HK40058071A - Longitudinal constraints for energy storage devices - Google Patents

Description

Longitudinal restraint for energy storage devices

This application is a divisional application of a patent application entitled "longitudinal restraint for an energy storage device" filed on 2016, 05 and 13 days, and having an application number of 201680039194.3.

Technical Field

The present disclosure relates generally to structures for energy storage devices, to energy storage devices incorporating such structures, and to methods for making such structures and energy devices.

Background

A rocking chair or plug-in secondary battery is a type of energy storage device in which carrier ions such as lithium ions, sodium ions, potassium ions, calcium ions, magnesium ions, or aluminum ions move between a positive electrode and a negative electrode through an electrolyte. A secondary battery may include a single battery cell or two or more battery cells that have been electrically coupled to form a battery, where each battery cell includes a positive electrode, a negative electrode, a microporous separator, and an electrolyte.

In the rocking chair type battery cell, both the positive and negative electrode structures include a material in which carrier ions are inserted and extracted. When the battery is discharged, carrier ions are extracted from the negative electrode and inserted into the positive electrode. When the battery is charged, the reverse process occurs: the carrier ions are extracted from the positive electrode and inserted into the negative electrode.

Fig. 1 shows a cross-sectional view of an electrochemical stack (stack) of a prior art energy storage device (e.g., non-aqueous, secondary battery). The electrochemical stack 1 includes a positive electrode current collector 3, a positive electrode active material layer 5, a microporous separator 7, a negative electrode active material layer 9, and a negative electrode current collector 11 in a stacked manner. Each layer has a height measured in the electrode stacking direction (i.e., in the direction from the positive electrode current collector 3 to the negative electrode current collector 11 as shown in fig. 1) that is significantly smaller (e.g., at least ten times smaller) than the length and width of each layer measured in the directions perpendicular to each other and perpendicular to the electrode stacking direction, respectively. Referring now to fig. 2, a roll 13 (sometimes referred to as a "jelly roll") having a top 15 and a bottom 17 is formed by winding an electrochemical stack around a central axis 19; the roll 13 is then loaded into a can (not shown), and filled with a nonaqueous electrolyte to assemble a secondary battery. As shown in fig. 2, the electrode stacking direction of the layers is orthogonal to the central axis 19.

Existing energy storage devices, such as batteries, fuel cells and electrochemical capacitors, typically have a two-dimensional layered structure (e.g., a planar or spiral wound stack) as shown in fig. 1 and 2, wherein the surface area of each stack is approximately equal to its geometric coverage (ignoring porosity and surface roughness). Three-dimensional batteries have been proposed in the literature as a means of increasing battery capacity and active material utilization. It has been proposed that three-dimensional structures can be used to provide higher surface area and higher energy than two-dimensional layered cell structures. It is beneficial to fabricate three-dimensional energy storage devices due to the increase in energy that can be obtained from a small geometric area. See, for example, Rust et al, WO2008/089110 and Long et al, "Three-Dimensional Battery architecture", Chemical Reviews, (2004), 104, 4463-4492.

Conventional wound batteries (see, e.g., U.S. patent nos. 6,090,505 and 6,235,427 and fig. 2) typically have electrode materials (active material, binder, conductive aid) coated onto a single foil and compressed prior to battery assembly. The foil on which the electrodes are coated is usually part of the current collection path. In a single jelly-roll battery, such as 18650 or a prismatic battery, the current collector foil is ultrasonically welded to an electrode bus, tab (tab), label (tag), or the like, which carries current from the active material through the current collector foil and tab to the exterior of the battery. Depending on the design, tabs may be present in multiple locations along a single jelly roll, or one location along one or both ends of the current collector foil. Conventional stacked pouch batteries have multiple plates (or foils) of active material, where the area on top of each foil is then gathered and welded together to tabs; which then carries the current to the exterior of the battery pouch (see, e.g., U.S. patent publication No. 2005/0008939).

However, one of the challenges associated with secondary batteries is the reliability and cycle life of the battery. For example, the electrode structure of a lithium ion battery tends to expand (swell) and contract as the battery is repeatedly charged and discharged, which in turn can lead to electrical shorting and failure of the device.

Disclosure of Invention

In various aspects of the present disclosure, three-dimensional structures for energy storage devices (e.g., batteries, fuel cells, and electrochemical capacitors) are provided. Advantageously, according to one aspect of the present disclosure, the proportion of electrode active material relative to other components of the energy storage device (i.e., inactive material components of the energy storage device) may be increased. As a result, an energy storage device including the three-dimensional structure of the present disclosure may have an increased energy density. They may also provide higher energy retrieval rates than two-dimensional energy storage devices for a specific amount of energy stored, for example by minimizing or reducing the transport distance for electron and ion transfer between the positive and negative electrodes. These devices may be more suitable for miniaturization and for applications where the geometrical area available for the device is limited and/or the energy density requirements are higher than what can be achieved with a layered device.

Briefly, therefore, according to one aspect of the present disclosure, there is provided an energy storage device for cycling between a charging state and a discharging state. The energy storage device includes a housing, an electrode assembly, and a non-aqueous liquid electrolyte within the housing, and a constraint that maintains pressure on the electrode assembly as the energy storage device cycles between a charged state and a discharged state. The electrode assembly has a set of electrode structures (a plating), a set of counter electrode structures and an electrically insulating microporous separator material between the electrodes and the components of the counter electrode set. The electrode assembly has opposing first and second longitudinal end surfaces spaced apart along the longitudinal axis and a side surface surrounding the longitudinal axis and connecting the first and second longitudinal end surfaces, the first and second longitudinal end surfaces having a combined surface area that is less than 33% of a combined surface area of the side surface and the first and second longitudinal end surfaces. The members of the electrode group and the members of the counter electrode group are arranged in an alternating order in a stacking direction parallel to the longitudinal axis within the electrode assembly. The restraint has first and second compression members connected by at least one tension member that pulls the compression members toward each other, and maintains a pressure on the electrode assembly in the stacking direction that exceeds a pressure maintained on the electrode assembly in each of two directions perpendicular to each other and to the stacking direction.

According to yet another aspect of the present disclosure, a secondary battery for cycling between a charged state and a discharged state is provided, the secondary battery having a battery case, an electrode assembly, and a non-aqueous liquid electrolyte within the battery case, and a constraint that maintains pressure on the electrode assembly as the secondary battery cycles between the charged state and the discharged state. The electrode assembly has a set of electrode structures, a set of counter electrode structures, and an electrically insulating microporous separator material between the electrodes and members of the counter electrode set. The electrode assembly has opposing first and second longitudinal end surfaces spaced apart along the longitudinal axis and side surfaces surrounding the longitudinal axis and connecting the first and second longitudinal end surfaces, the first and second longitudinal end surfaces having a surface area that is less than 33% of a surface area of the electrode assembly. The members of the electrode group and the members of the counter electrode group are arranged in an alternating order in a stacking direction parallel to the longitudinal axis within the electrode assembly. A projection of the electrode group and the member of the counter electrode group on the first longitudinal surface encloses a first projection area, and a projection of the electrode group and the member of the counter electrode group on the second longitudinal surface encloses a second projection area. The restraining has first and second compression members respectively overlying the first and second projection regions, the compression members being connected by a tension member overlying side surfaces of the electrode assembly and pulling the compression members toward each other, and restrains a pressure on the electrode assembly maintained in the stacking direction, the pressure exceeding a pressure maintained on the electrode assembly in each of two directions perpendicular to each other and to the stacking direction.

Other objects and features will be in part apparent and in part pointed out hereinafter.

Drawings

Fig. 1 is a cross-section of an electrochemically stacked cell of a two-dimensional energy storage device of the prior art, such as a lithium ion cell.

Fig. 2 is a cross-section of a wound electrochemically stacked cell of a prior art two-dimensional energy storage device, such as a lithium ion battery.

Fig. 3A is a schematic view of one embodiment of an electrode assembly of the present disclosure having a triangular prism shape.

Fig. 3B is a schematic diagram of one embodiment of an electrode assembly of the present disclosure having a parallelepiped shape.

Fig. 3C is a schematic view of one embodiment of an electrode assembly of the present disclosure having a rectangular prism shape.

Fig. 3D is a schematic diagram of one embodiment of an electrode assembly of the present disclosure having a pentagonal prismatic shape.

Fig. 3E is a schematic diagram of one embodiment of an electrode assembly of the present disclosure having a hexagonal prism shape.

Fig. 4 is a schematic exploded view of one embodiment of a secondary battery of the present disclosure.

Fig. 5A is a schematic end view of one end of an electrode assembly of the secondary battery of fig. 4.

Fig. 5B is a schematic end view of the opposite end of the electrode assembly of fig. 5A.

Fig. 5C is a schematic top view of a side surface of the electrode assembly of fig. 5A.

Fig. 5D is a schematic bottom view of the opposite side surface of the electrode assembly of fig. 5A.

Fig. 6A is a schematic perspective view of the restraint of the secondary battery of fig. 4.

Figure 6B illustrates an embodiment of a cross section of an electrode assembly with a constraint that employs an internal compression member.

Figure 6C illustrates an embodiment of a cross section of an electrode assembly with a constraint that employs multiple internal compression members.

Fig. 7 is a schematic exploded view of an alternative embodiment of the secondary battery of the present disclosure.

Fig. 8 is a schematic view of an alternative embodiment of the restraint of the electrode assembly of the secondary battery of the present disclosure in an expanded form.

Fig. 9 is a schematic illustration of the constraint of fig. 8 after folding.

Fig. 10A is a schematic view of an alternative embodiment of a restraint and electrode assembly of the secondary battery of the present disclosure.

Fig. 10B is an enlarged view of the restraint and electrode assembly of fig. 10A.

Fig. 11A is a schematic view of an alternative embodiment of the restraint for the electrode assembly of the secondary battery of the present disclosure.

FIG. 11B is an enlarged view of the constraint of FIG. 11A.

Fig. 12A is a perspective view, partially broken away to show the internal structure, of one embodiment of an electrode assembly of a secondary battery of the present disclosure.

Fig. 12B is an end view of one end of the electrode assembly of fig. 12A.

Fig. 12C is an end view of the opposite end of the electrode assembly of fig. 12A.

Fig. 13 is a perspective view, with portions broken away to show the internal structure, of an alternative embodiment of a secondary battery of the present disclosure.

Fig. 14 is a perspective view, with portions broken away to show the internal structure, of an alternative embodiment of a secondary battery of the present disclosure.

Fig. 15 is a perspective view, with portions broken away to show the internal structure, of an alternative embodiment of a secondary battery of the present disclosure.

Fig. 16 is a cross-sectional view of an alternative embodiment of a restraint and electrode assembly of the present disclosure.

Corresponding reference characters indicate corresponding parts throughout the drawings.

Detailed Description

As used herein, the terms "a," "an," and "the" (i.e., singular forms) refer to a plurality of referents unless the context clearly dictates otherwise. For example, in one example, reference to "an electrode" includes a single electrode and a plurality of similar electrodes.

As used herein, "about" and "approximately" mean plus or minus 10%, 5%, or 1% of the stated value. For example, in one example, about 250 μm would include 225 μm to 275 μm. As a further example, in one example, about 1000 μm would include 900 μm to 1100 μm. Unless otherwise indicated, all numbers expressing quantities (e.g., measured values, etc.) and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations. Each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

As used herein, "state of charge" in the case of the state of the secondary battery refers to a state in which the secondary battery is charged to at least 75% of its rated capacity. For example, the battery may be charged to at least 80% of its rated capacity, at least 90% of its rated capacity, even at least 95% of its rated capacity, such as 100% of its rated capacity.

As used herein, the "discharge state" in the case of the state of the secondary battery refers to a state in which the secondary battery is discharged to less than 25% of its rated capacity. For example, a battery may be discharged to less than 20% of its rated capacity, such as less than 10% of its rated capacity, or even less than 5% of its rated capacity, such as 0% of its rated capacity.

As used herein, "cycling" in the context of cycling of a secondary battery between a charged state and a discharged state refers to charging and/or discharging the battery to cause the battery to move in a cyclical manner from a first state of either the charged state or the discharged state back to a second state opposite the first state (i.e., the charged state if the first state is discharged and the discharged state if the first state is charged), and then moving the battery back to the first state to complete the cycle. For example, a single cycle of a secondary battery between a charged state and a discharged state may include charging the battery from the discharged state to the charged state, and then discharging back to the discharged state to complete the cycle. A single cycle may also include discharging the battery from a charged state to a discharged state, and then charging back to the charged state to complete the cycle.

The "Feret diameter" as referred to herein with respect to the electrode assembly is defined as the distance between two parallel planes of the electrode assembly measured in a direction perpendicular to the two planes.

As used herein, "longitudinal axis," "lateral axis," and "vertical axis" refer to axes that are perpendicular to each other (i.e., each is orthogonal to each other). For example, "longitudinal axis," "lateral axis," and "vertical axis" as used herein are analogous to a Cartesian coordinate system used to define three-dimensional aspects or orientations. As such, the description herein of elements of the inventive subject matter is not limited to a particular axis or axes for describing the three-dimensional orientation of the elements. Alternatively, these axes may be interchangeable as it relates to the three-dimensional aspects of the inventive subject matter.

As used herein, "longitudinal direction", "transverse direction", and "vertical direction" refer to directions that are perpendicular to each other (i.e., each is orthogonal to each other). For example, "longitudinal direction," "lateral direction," and "vertical direction" as used herein may be generally parallel to the longitudinal, lateral, and vertical axes, respectively, of a cartesian coordinate system used to define a three-dimensional aspect or orientation.

As used herein, "repetitive cycling" in the case of cycling between a charged state and a discharged state of a secondary battery refers to cycling from the discharged state to the charged state or from the charged state to the discharged state more than once. For example, repeated cycling between a charged state and a discharged state may include cycling at least 2 times from the discharged state to the charged state, such as charging from the discharged state to the charged state, discharging back to the discharged state, recharging to the charged state, and finally discharging back to the discharged state. As yet another example, the repeating cycle between the charged state and the discharged state at least 2 times may include discharging from the charged state to the discharged state, charging back to the charged state, discharging again to the discharged state and finally charging back to the charged state. As a further example, the repeated cycling between the charged state and the discharged state may include cycling at least 5 times, and even cycling at least 10 times from the discharged state to the charged state. As a further example, repeated cycling between the charging state and the discharging state may include cycling from the discharging state to the charging state at least 25, 50, 100, 300, 500, and even 1000 times.

As used herein, "rated capacity" in the context of a secondary battery refers to the ability of the secondary battery to deliver current over a period of time as measured under standard temperature conditions (25 ℃). For example, the rated capacity may be measured in ampere-hours, or by determining the current output for a particular time, or by determining the time at which a current may be output for a particular current, and multiplying the current by the time. For example, for a battery rated for 20 amp-hours, if the current is specified at a rate of 2 amps, the battery may be understood as a battery capable of providing a 10 hour current output, whereas if the time is specified at a rate of 10 hours, the battery may be understood as a battery that will output 2 amps during 10 hours.

In general, a secondary battery of the present disclosure includes a battery case, an electrode assembly, and a non-aqueous liquid electrolyte within the battery case, and a constraint that maintains pressure on the electrode assembly as the secondary battery cycles between a charged state and a discharged state. As previously described, during formation of the secondary battery and/or subsequent cycling of the secondary battery between a charged state and a discharged state, the electrode and/or the counter electrode within the electrode assembly may expand along the stacking direction of the electrode and the counter electrode (i.e., the electrode stacking direction). Such expansion presents challenges when the electrode assembly includes tens (or even more) of stacked electrodes and counter electrodes. Advantageously, the constraints of the present disclosure maintain pressure on the electrode assembly during formation of the cell and/or during subsequent cycling of the cell between a charged state and a discharged state, which inhibits expansion of the electrode assembly (in the stacking direction). In addition, the constraint further inhibits buckling of the electrode assembly, which may be caused by a difference in pressure applied to different surfaces of the electrode assembly by the constraint.

The constraints of the present disclosure may be embodied in any one of a series of structures including: for example, the battery housing itself, structures external to the battery housing, structures internal to the battery housing, or even a combination of the battery housing, structures internal to the battery housing, and/or structures external to the battery housing. In one such embodiment, the battery housing is a restraining member; in other words, in this embodiment, the cell housing alone or in combination with one or more other structures (within and/or outside the cell housing) exerts a pressure on the electrode structure in the direction of electrode stacking that is greater than the pressure exerted on the electrode structure in directions that are perpendicular to each other and to the direction of electrode stacking. In another embodiment, the constraint does not include the cell housing and one or more discrete structures (within and/or external to the cell housing) other than the cell housing, the pressure exerted on the electrode structures in the electrode stacking direction being greater than the pressure exerted on the electrode structures in directions perpendicular to the electrode stacking direction and perpendicular to each other.

In one exemplary embodiment, constraining includes one or more discrete structures within the cell housing that exert a pressure on the electrode structure in the electrode stacking direction that exceeds the pressure exerted on the electrode structure in two directions that are perpendicular to the electrode stacking direction and to each other.

In one exemplary embodiment, the electrode structure is constrained within the cell housing and exerts a pressure on the electrode structure in the electrode stacking direction that exceeds the pressure exerted on the electrode structure in two directions that are perpendicular to the electrode stacking direction and to each other.

In one exemplary embodiment, the constraints include one or more discrete structures external to the cell housing and one or more discrete structures within the cell housing that, in combination, exert a pressure on the electrode structure in the electrode stacking direction that exceeds the pressure exerted on the electrode structure in two directions that are perpendicular to the electrode stacking direction and to each other.

Independently of the location of the restraint (e.g., inside or outside of, and/or contained by, the battery housing), the restraint and the battery housing jointly and preferably occupy no more than 75% of the volume bounded by the outer surface of the battery housing (i.e., the displaced volume of the battery). For example, in one such embodiment, the restraint and the battery housing jointly occupy no more than 60% of the volume bounded by the outer surface of the battery housing. As a further example, in one such embodiment, the restraint and the battery housing jointly occupy no more than 45% of the volume bounded by the outer surface of the battery housing. As a further example, in one such embodiment, the restraint and the battery housing jointly occupy no more than 30% of the volume bounded by the outer surface of the battery housing. As a further example, in one such embodiment, the restraint and the battery housing jointly occupy no more than 20% of the volume bounded by the outer surface of the battery housing.

The electrode assemblies of the present disclosure generally include two opposing longitudinal end surfaces (separated along a longitudinal axis of the electrode assembly) and a side surface (which surrounds the longitudinal axis) extending between the two opposing longitudinal end surfaces. Generally, the longitudinal end surfaces may be planar or non-planar. For example, in one embodiment, the opposing longitudinal end surfaces are convex. As a further example, in one embodiment, the opposing longitudinal end surfaces are concave. As a further example, in one embodiment, the opposing longitudinal end surfaces are substantially planar.

The opposing longitudinal end surfaces may also have any range of two-dimensional shapes when projected onto a plane. For example, the longitudinal end surfaces may independently have a smoothly curved shape (e.g., circular, elliptical, hyperbolic, or parabolic), they may independently include a series of lines and vertices (e.g., polygonal), or they may independently include a smoothly curved shape and include one or more lines and vertices. Similarly, the side surface of the electrode assembly may be a smoothly curved shape (e.g., the electrode assembly has a circular, elliptical, hyperbolic, or parabolic cross-sectional shape), or the side surface may include two or more faces connected at a vertex (e.g., the electrode assembly may have a polygonal cross-section). For example, in one embodiment, the electrode assembly has a cylindrical, elliptical cylindrical, parabolic cylindrical, or hyperbolic cylindrical shape. As a further example, in one such embodiment, the electrode assembly may have a prismatic shape, opposing longitudinal end surfaces of the same size and shape, and parallelogram-shaped side surfaces (i.e., faces extending between the opposing longitudinal end surfaces). As a further example, in one such embodiment, the electrode assembly has a shape corresponding to a triangular prism, the electrode assembly having two opposing triangular longitudinal end surfaces and a side surface comprising three parallelograms (e.g., rectangles) extending between the two longitudinal end surfaces. As a further example, in one such embodiment, the electrode assembly has a shape corresponding to a rectangular prism, the electrode assembly having two opposing rectangular longitudinal end surfaces and a side surface comprising four parallelogram (e.g., rectangular) faces. By way of further example, in one such embodiment, the electrode assemblies have a shape corresponding to a pentagonal prism, a hexagonal prism, etc., wherein the electrode assemblies each have opposing longitudinal end surfaces of two pentagonal, hexagonal, etc., faces and side surfaces of a parallelogram (e.g., rectangular) face each including five, six, etc.

Referring now to fig. 3A-3E, several exemplary geometries are schematically illustrated for electrode assembly 120. In fig. 3A, the electrode assembly 120 has a triangular prismatic shape with opposing first and second longitudinal end surfaces 122, 124 separated along a longitudinal axis a, and a side surface (not labeled) including three rectangular faces connecting the longitudinal end surfaces and surrounding the longitudinal axis a. In fig. 3B, the electrode assembly 120 has a parallelepiped shape with opposing first and second parallelogram-shaped longitudinal end surfaces 122, 124 separated along the longitudinal axis a, and side surfaces (not labeled) including four parallelogram-shaped faces connecting the two longitudinal end surfaces and surrounding the longitudinal axis a. In fig. 3C, the electrode assembly 120 has a rectangular prismatic shape with opposing first and second rectangular longitudinal end surfaces 122, 124 separated along the longitudinal axis a, and a side surface (not labeled) including four rectangular faces connecting the two longitudinal end surfaces and surrounding the longitudinal axis a. In fig. 3D, the electrode assembly 120 has a pentagonal prismatic shape with opposing first and second pentagonal longitudinal end surfaces 122, 124 spaced apart along a longitudinal axis a, and a side surface (not labeled) including five rectangular faces connecting the two longitudinal end surfaces and surrounding the longitudinal axis a. In fig. 3E, the electrode assembly 120 has a hexagonal prismatic shape with opposing first and second hexagonal longitudinal end surfaces 122, 124 separated along the longitudinal axis a, and a side surface (not labeled) comprising six rectangular faces connecting the two longitudinal end surfaces and surrounding the longitudinal axis a.

The opposing first and second longitudinal end surfaces of the electrode assembly have a combined surface area that is less than 50% of a total surface area of the electrode assembly (i.e., the total surface area is the sum of the surface areas of the first and second longitudinal end surfaces and the surface areas of the side surfaces of the electrode assembly), independent of the overall geometry of the electrode assembly. For example, the first and second opposing longitudinal end surfaces 122, 124 of the electrode assembly 120 of each of fig. 3A-3E each have a combined surface area (i.e., the sum of the surface areas of the first and second longitudinal end surfaces) that is less than 50% of the total surface area of a triangular prism (fig. 3A), a parallelepiped (fig. 3B), a rectangular prism (fig. 3C), a pentagonal prism (fig. 3D), or a hexagonal prism (fig. 3E), respectively. For example, in one such embodiment, the opposing first and second longitudinal end surfaces of the electrode assembly have a surface area that is less than 33% of the total surface of the electrode assembly. As a further example, in one such embodiment, the opposing first and second longitudinal end surfaces of the electrode assembly have a surface area that is less than 25% of the total surface of the electrode assembly. As a further example, in one such embodiment, the opposing first and second longitudinal end surfaces of the electrode assembly have a surface area that is less than 20% of the total surface of the electrode assembly. As a further example, in one such embodiment, the opposing first and second longitudinal end surfaces of the electrode assembly have a surface area that is less than 15% of the total surface of the electrode assembly. As a further example, in one such embodiment, the opposing first and second longitudinal end surfaces of the electrode assembly have a surface area that is less than 10% of the total surface of the electrode assembly.

In some embodiments, the electrode assembly is a rectangular prism, and the first and second opposing longitudinal end surfaces have a combined surface area that is less than the combined surface area of at least two opposing faces of the side surface (i.e., the sum of the surface areas of two opposing rectangular sides connecting the opposing longitudinal end surfaces). In some embodiments, the electrode assembly is a rectangular prism having first and second opposing longitudinal end surfaces and a side surface comprising two pairs of opposing surfaces (facets), and the two opposing longitudinal end surfaces have a combined surface area that is less than the combined surface area of at least one of the two pairs of opposing facets comprised by the side surface. In some embodiments, the electrode assembly is a rectangular prism having two opposing first and second longitudinal end surfaces and a side surface comprising two pairs of opposing surfaces (faces), and the two opposing longitudinal end surfaces have a combined surface area that is less than the combined surface area of each of the two pairs of opposing faces comprised by the side surface.

Generally, the electrode assembly includes an electrode group and a counter electrode group stacked in a direction (i.e., an electrode stacking direction) coinciding with a longitudinal axis (see, e.g., fig. 3A-3E) of the electrode assembly. In other words, the electrode and the counter electrode are stacked in a direction extending from a first opposite longitudinal end surface to a second opposite longitudinal end surface of the electrode assembly. In one embodiment, the members of the electrode set and/or the members of the counter electrode set are layered in nature (see, e.g., fig. 1 and 2). In another embodiment, the members of the electrode set and/or the members of the counter electrode set are non-layered in nature; in other words, in one embodiment, the members of the electrode and/or counter electrode set extend sufficiently from an imaginary backing plate (e.g., a plane substantially coincident with the surface of the electrode assembly) to have a surface area (neglecting porosity) that is two times higher than the geometric dimensions (i.e., projection) of the members in the backing plate. In certain embodiments, the ratio of the surface area of the non-laminar (i.e., three-dimensional) electrode and/or counter electrode structure to its geometric dimension in the imaginary backplane may be at least about 5, at least about 10, at least about 50, at least about 100, or even at least about 500. Typically, however, the ratio will be between about 2 and about 1000. In one such embodiment, the components of the electrode assembly are non-layered in nature. As a further example, in one such embodiment, the members of the counter electrode set are non-layered in nature. As a further example, in one such embodiment, the members of the electrode set and the members of the counter electrode set are non-layered in nature.

Expansion of the electrode assembly in the longitudinal direction (e.g., in a direction parallel to the longitudinal axis a in each of fig. 3A-3E) may be inhibited by the constraints of the present disclosure during formation of a secondary battery containing the electrode assembly and/or during cycling. Generally, the constraint comprises compression members (adapted to overlie the first and second projected regions, respectively) connected by tensioning members (adapted to overlie the side surfaces of the electrode assembly). The tensioning members tend to pull the compression members toward each other, thereby applying a compressive force to the opposing first and second longitudinal end surfaces of the electrode assembly, which in turn inhibits expansion of the electrode assembly in the longitudinal direction (which coincides with the electrode stacking direction as described further herein). In addition, after the battery is formed, it is restrained that pressure, which exceeds the pressure maintained on the electrode assembly in each of two directions perpendicular to each other and to the longitudinal direction, is applied to the electrode assembly in the longitudinal direction (i.e., the electrode stacking direction).

Referring now to fig. 4, there can be seen an exploded view of one embodiment of the secondary battery of the present disclosure, generally designated 100. The secondary battery includes a battery case 102 and a collection 110 of electrode assemblies 120 within the battery case 102, each electrode assembly having a first longitudinal end surface 122, an opposing second longitudinal end surface 124 (separated from the first longitudinal end surface 122 along a longitudinal axis (not shown) that is parallel to the "Y-axis" of the imaginary cartesian coordinate system of fig. 4), and side surfaces including sides 123, 125, 126, 127 (see fig. 12A). Each electrode assembly includes a set of electrode structures and a set of counter electrode structures, which are stacked relative to each other in each electrode assembly in an electrode stacking direction D (see, e.g., fig. 12A); in other words, the sets of electrode and counter electrode structures are arranged in an alternating series of electrodes and counter electrodes, with the series advancing in a direction D between the first and second longitudinal end surfaces 122, 124 (see, e.g., FIG. 12A; as shown in FIG. 4, the electrode stacking direction D is parallel to the Y-axis of the imaginary Cartesian coordinate system of FIG. 4). Further, the electrode stacking direction D within each electrode assembly 120 is perpendicular to the stacking direction of the set of electrode assemblies 120 within the set 110 (i.e., the electrode assembly stacking direction); in other words, the electrode assemblies are arranged relative to each other in a direction within the set 110 that is perpendicular to the electrode stacking direction D within a single electrode assembly (e.g., the electrode assembly stacking direction is a direction corresponding to the Z-axis of an imaginary cartesian coordinate system, and the electrode stacking direction D within each electrode assembly is a direction corresponding to the Y-axis of the imaginary cartesian coordinate system).

Tabs 141, 142 extend out of the battery case and provide electrical connection between the electrode assemblies of the pack 110 and an energy supply or consumer (not shown). More specifically, in this embodiment, the tab 141 is electrically connected to the tab extension 143 (using, for example, conductive paste), and the tab extension 143 is electrically connected to the electrode included by each electrode assembly 120. Similarly, the tab 142 is electrically connected to the tab extension 144 (using, for example, conductive adhesive), and the tab extension 144 is electrically connected to the counter electrode included by each electrode assembly 120.

Each electrode assembly 120 in the embodiment shown in fig. 4 has an associated constraint 130 to inhibit expansion in the longitudinal direction (i.e., the electrode stacking direction D). Each constraint 130 includes a compression member 132, 134 (see fig. 5A and 5B) overlying first and second longitudinal end surfaces 122, 124, respectively, and a tension member 133, 135 (see fig. 5C and 5D) overlying sides 123, 125, respectively. The tensioning members 133, 135 pull the compression members 132, 134 toward each other and the compression members 132, 134 apply a compressive force to the opposing first and second longitudinal end surfaces 122, 124. As a result, expansion of the electrode assembly in the longitudinal direction is suppressed during formation of the battery and/or cycling of the battery between a charged state and a discharged state. Further, the constraint 130 exerts a pressure on the electrode assembly in the longitudinal direction (i.e., the electrode stacking direction D) that exceeds a pressure maintained on the electrode structure in either one of two directions that are mutually perpendicular to each other and to the longitudinal direction (as shown, the longitudinal direction corresponds to the direction of the "Y" axis of the imaginary cartesian coordinate system shown, and mutually perpendicular to each other and to the two directions perpendicular to the longitudinal direction correspond to the directions of the X axis and the Z axis of the imaginary cartesian coordinate system shown, respectively).

Referring now to fig. 5A, 5B, 5C, and 5D, each electrode assembly 120 in the embodiment of fig. 4 has a geometry corresponding to the geometry of a rectangular prism: having a dimension X₁×Z₁Has a dimension X, and first and second longitudinal end surfaces 122, 124₁×Y₁And has a dimension Y, and side surfaces 123, 125₁×Z₁Side surfaces 126, 127 (wherein, X)₁、Y₁And Z₁Dimensions measured in directions corresponding to the X, Y and Z axes, respectively, of a cartesian coordinate system). The first and second longitudinal end surfaces 122, 124 thus have an X-dimension₁And Z₁The surface area corresponding to the product of (a), the sides 123, 125 each having a surface area corresponding to X₁And Y₁Product ofCorresponding surface areas, and sides 126, 127 each having a surface area corresponding to Y₁And Z₁The product corresponds to the surface area. According to one aspect of the present disclosure, a sum of surface areas of the first and second longitudinal end surfaces is less than 33% of a surface area of a total surface of the electrode assembly, wherein the electrode assembly is a rectangular prism, and a combined surface area of the first and second longitudinal end surfaces is equal to (X)₁*Z₁)+(X₁*Z₁) And the surface area of the side surface is equal to (X)₁*Y₁)+(X₁*Y₁)+(Y₁*Z₁)+(Y₁*Z₁). For example, in one such embodiment, the sum of the surface areas of the first and second longitudinal end surfaces is less than 25% of the surface area of the total surface of the electrode assembly, wherein the combined surface area of the first and second longitudinal end surfaces is equal to (X)₁*Z₁)+(X₁*Z₁) And the total surface of the electrode assembly is equal to (X)₁*Y₁)+(X₁*Y₁)+(Y₁*Z₁)+(Y₁*Z₁)+(X₁*Z₁)+(X₁*Z₁)。

Each constraint 130 in this embodiment includes a compression member 132, 134 overlying the first and second longitudinal end surfaces 122, 124, respectively, and at least one tension member pulling the compression members toward each other. For example, the constraint may include tensioning members 133, 135 overlying the sides 123, 125 of the side surfaces, respectively. Generally, the compression members 132, 134 exert a pressure on the first and second longitudinal end surfaces 122, 124 (i.e., in the electrode stacking direction D) that exceeds the pressure maintained on the side surfaces 123, 125 and on the side surfaces 126, 127 of the electrode assembly (i.e., in each of two directions that are perpendicular to each other and to the electrode stacking direction). For example, in one such embodiment, the application of pressure on the first and second longitudinal end surfaces 122, 124 (i.e., in the electrode stacking direction D) is constrained to exceed at least 3 times the pressure maintained on the electrode assembly in at least one of two directions perpendicular to the electrode stacking direction and perpendicular to each other, or even in both directions. As another example, in one such embodiment, the pressure is constrained to be applied (i.e., in the electrode stacking direction D) on the first and second longitudinal end surfaces 122, 124 that exceeds at least 4 times the pressure maintained on the electrode assembly in at least one of two directions perpendicular to the electrode stacking direction and perpendicular to each other, or even in both directions. As another example, in one such embodiment, the pressure is constrained to be applied (i.e., in the electrode stacking direction D) on the first and second longitudinal end surfaces 122, 124 that exceeds at least 5 times the pressure maintained on the electrode assembly in at least one of two directions perpendicular to the electrode stacking direction and perpendicular to each other, or even in both directions.

Referring now to FIG. 6A, in one embodiment, constraints 130 may originate from having a length L₁Width W₁And a thickness t₁The sheet 107. To form the restraint, the sheet 107 is simply wrapped around the electrode structure 120 (see fig. 4 and 5A-5D) and folded at fold line 113 to enclose the electrode structure. The edges 115, 117 overlap each other and are welded, glued or otherwise secured to each other to form a constraint that includes compression members 132, 134 (compression member 134 includes overlapping edges 115, 177 once secured to each other) and tension members 133, 135. In this embodiment, the constraint has a displacement volume (i.e., L) corresponding to the sheet 107₁、W₁And t₁Product of) is determined.

The sheet 107 may comprise any of a wide range of compatible materials capable of applying the desired force to the electrode structure. Typically, the constraint will typically include having a value of at least 10000 psi: (b>70MPa) that is compatible with the battery electrolyte, that does not significantly corrode at the floating (floating) or anode potential of the battery, and that does not significantly react or lose mechanical strength at 45 ℃. For example, constraints may include any of a wide range of metals, alloys, ceramics, glass, plastics, or combinations thereof (i.e., composites). In one exemplary embodiment, constraints include metals such as stainless steel (e.g., SS316, 440C, or 440C hard), aluminum (e.g., aluminum 7075-T6, hard H18), titanium (e.g., 6Al-4V), beryllium copper (hard), copper (oxygen free, hard), nickel; however, in general, when aboutWhen the bundle comprises metal, it is generally preferred to combine in a manner that limits corrosion and creates an electrical short between the electrode and the counter electrode. In another exemplary embodiment, the constraint comprises a ceramic, such as alumina (e.g., sintered or Coorstek AD96), zirconia (e.g., Coorstek YZTP), yttria-stabilized zirconia (e.g., ENrG)). In another exemplary embodiment, the constraint comprises glass such as Schott D263 tempered glass. In another exemplary embodiment, the constraint comprises a plastic, such as Polyetheretherketone (PEEK) (e.g., Aptiv 1102), PEEK with carbon (e.g., Victrex 90HMF40 or Xycomp 1000-04), polyphenylene sulfide (PPS) with carbon (e.g., Tepex Dynalite 207), Polyetheretherketone (PEEK) with 30% glass (e.g., Victrex 90HMF40 or Xycomp 1000-04), polyimide (e.g.,). In another exemplary embodiment, the constraint comprises a composite material such as E glass standard fiber/epoxy, 0 degree, E glass UD/epoxy, 0 degree, Kevlar standard fiber/epoxy, 0 degree, Kevlar UD/epoxy, 0 degree, carbon standard fiber/epoxy, 0 degree, carbon UD/epoxy, 0 degree, ToyoboHM fibers/epoxy. In another exemplary embodiment, the constraint comprises a fiber, such as Kevlar 49 aramid fiber, S-glass fiber, carbon fiber, Vectran UM LCP fiber, Dyneema, Zylon.

Thickness of constraint (t)₁) Will depend on a number of factors including, for example, the materials of construction of the restraint, the overall size of the electrode assembly, and the composition of the cell's anodes and cathodes. In some embodiments, for example, the constraint will comprise a sheet having a thickness in the range of about 10 microns to about 100 microns. For example, in one such embodiment, the constraint comprises a sheet of stainless steel (e.g., SS316) having a thickness of about 30 μm. As a further example of the use of the invention,in another such embodiment, the constraint comprises an aluminum foil (e.g., 7075-T6) having a thickness of about 40 μm. As another example, in another such embodiment, the constraint comprises a zirconia flake having a thickness of about 30 μm (e.g., Coorstek YZTP). As another example, in another such embodiment, the constraint comprises an E-glass UD/epoxy 0 degree laminate having a thickness of about 75 μm. As another example, in another such embodiment, the constraints include>A 12 μm carbon fiber of 50% packing density.

In certain embodiments, the constrained compression member and/or the tensioning member comprise a porous material. Generally, the porous material will allow easy access of the electrolyte to the electrode assembly. For example, in some embodiments, the compression members and/or tension members may have a void fraction of at least 0.25. As another example, in some embodiments, the compression member and/or the tension member may have a void fraction of at least 0.375. As another example, in some embodiments, the compression members and/or tension members may have a void fraction of at least 0.5. As another example, in some embodiments, the compression members and/or tension members may have a void fraction of at least 0.625. As another example, in some embodiments, the compression members and/or tension members may have a void fraction of at least 0.75.

In yet another embodiment, the constraint 130 includes one or more compression members inside the electrode assembly 120. For example, referring now to FIG. 6B, a cross-section of an embodiment of an electrode assembly 120 having a constraint 130 with an internal compression member 132a is shown. In the embodiment shown in fig. 6B, the constraint 130 may include first and second compression members 132, 134 at the longitudinal end surfaces 122, 124 of the electrode assembly 120, respectively. However, additionally and/or alternatively, the constraint 130 may further comprise at least one inner compression member 132a, the inner compression member 132a being located at an inner region of the electrode assembly other than the longitudinal end surfaces 122, 124. The inner compression member 132a may be connected to the tension members 133, 135 to apply a compressive pressure to a portion of the electrode assembly 120 between the inner compression member 132a and another compression member (e.g., one or more compression members 132, 134 at the longitudinal end surfaces 122, 124 of the electrode assembly 120 and/or one or more other inner compression members 132). Referring to the embodiment shown in fig. 6B, an inner compression member 132a may be provided, the inner compression member 132a being spaced apart along the longitudinal axis (stacking direction D) away from the first and second longitudinal end surfaces 122, 124 of the electrode assembly 120, respectively, e.g., toward a central region of the electrode assembly 120. The inner compression member 132a may be connected to the tension members 133, 135 at an inner position away from the electrode assembly end surfaces 122, 124. In one embodiment, in addition to the compression members 132, 134 provided at the electrode assembly end surfaces 122, 124, at least one inner compression member 132a is provided at an inner position remote from the end surfaces 122, 124. In another embodiment, the constraint 130 includes an internal compression member 132a at an internal location of the electrode assembly 120 that is spaced internally from the longitudinal end surfaces 122, 124, with or without compression members 132, 134 at the longitudinal end surfaces 122, 124. In yet another embodiment, the restraint 130 includes an internal compression member 132a at an internal location of the electrode assembly that is spaced internally from the longitudinal end surfaces 122, 124 without the compression members 132, 134 at the longitudinal end surfaces 122, 124. In one embodiment, the internal compression member 132a may be understood to act with one or more of the compression members 132, 134 and/or the other internal compression member 132a to apply a compressive pressure on each portion of the electrode assembly 120 in the longitudinal direction between the internal compression member 132a and the longitudinal surfaces 122, 124 of the electrode assembly 120 where the compression members 132, 134 are located, and/or to apply a compressive pressure on portions of the electrode assembly 120 in the longitudinal direction between the internal compression member 132a and the other internal compression member 132 a. In one version, at least one of the internal compression members 132a includes at least a portion of an electrode or counter electrode structure 151, 152, as described in further detail below. For example, the internal compression member 132a may include the counter electrode active material, the separator, the electrode current collector, the counter electrode current collector, the electrode stem, and at least a portion of the counter electrode stem.

According to one embodiment, as described above, the constraint 130 may include an inner compression member 132a, the inner compression member 132a being part of the inner structure of the electrode assembly 106, such as part of the electrode 151 and/or counter electrode structure 152. In one embodiment, by providing compression between structures within the electrode assembly 120, a tightly constrained structure may be achieved that is sufficiently compensated for the tension created by the growth of the electrode structure 120. For example, in one embodiment, one or more internal compression members 132 may act with compression members 132, 134 at longitudinal end surfaces 122, 124 of electrode assembly 120 to constrain growth in a direction parallel to the longitudinal direction by being in tension with each other via connecting tension members 133, 135. In yet another embodiment, growth of the electrode structure 151 (e.g., an anode structure) may be counteracted by compression via one or more internal compression members 132a corresponding to portions of the counter electrode structure 152 (e.g., a cathode), which are in tension with each other via the tension members 133, 135.

In general, in some embodiments, the components of the restraint 130 may be implemented as the electrode 151 and/or counter electrode structure 152, respectively, within the electrode assembly 120, not only to provide effective restraint, but to more effectively utilize the volume of the electrode assembly 120 without unduly increasing the size of the secondary battery having the electrode assembly 120. For example, in one embodiment, the constraint 130 may comprise tensioning members 133, 135 attached to one or more electrode structures 151 and/or counter electrode structures 152 serving as the internal compression member 132 a. As a further example, in certain embodiments, the at least one internal compression member 132a may be implemented as a set of electrode structures 151. As a further example, in certain embodiments, the at least one internal compression member 132a may be implemented as a set of counter electrode structures 152.

Referring now to FIG. 6C, a Cartesian coordinate system having a vertical axis (Z axis), a longitudinal axis (Y axis), and a lateral axis (X axis) is shown; wherein the X-axis is oriented out of the plane of the page; and the designation of the stacking direction D as described above is co-parallel with the Y-axis. More specifically, fig. 7 shows a cross-section of an electrode assembly 120 having a constraint 130, the constraint 130 having compression members 132, 134 at its longitudinal surfaces and at least one internal compression member 132 a. The constraint 130 comprises compression members 132, 134 and internal compression members implemented as sets of electrode structures 151 and/or sets of counter electrode structures 152; thus, in this embodiment, the at least one internal compression member 132a, electrode structure 151 and/or counter electrode structure 152 may be understood to be interchangeable. Also, the diaphragm 150 may also form a portion of the internal compression member 132 a. More specifically, shown in fig. 6C is one embodiment of a flush (flush) connection corresponding to the internal compression member 132a of the electrode 151 or counter electrode structure 152. The flush connection may further include an adhesive layer 182 otherwise adhered between the tension members 133, 135 and the internal compression member 132 a. The adhesive layer 182 secures the internal compression member 132a to the tensioning members 133, 135 so that the internal compression member 132a can be maintained in tension with other compression members, such as other internal compression members or compression members at the longitudinal end surfaces of the electrode assembly 120.

As further shown in fig. 6C, in one embodiment, the components of the electrode group 151 have an electrode active material layer 160, an electrode current collector 163 (such as an ion porous electrode current collector), and an electrode stem 165 supporting the electrode active material layer 160 and the electrode current collector 163. Similarly, in one embodiment, as shown in fig. 6C, the members of the counter electrode group 152 have a counter electrode active material layer 167, a counter electrode current collector 169, and a counter electrode stem 171 supporting the counter electrode active material layer 167 and the counter electrode current collector 169.

Without being bound by any particular theory (e.g., as shown in fig. 6C), in certain embodiments, the components of the electrode group 151 include an electrode active material layer 160, an electrode current collector 163, and an electrode stem 165 supporting the electrode active material layer 160 and the electrode current collector 163. Similarly, in certain embodiments, the components of the counter electrode group 152 include a counter electrode active material layer 167, a counter electrode current collector 169, and a counter electrode stem 171 supporting the counter electrode active material layer 167 and the counter electrode current collector 169. In one embodiment, at least a portion of any of the electrode and counter electrode structures 151, 152, such as the current collectors 163, 169, stems 165, 171, counter electrode active material layer 167, and separator 130, may serve as part or all of the inner compression member 132a, such as by being connected to the tension members 133, 135 or otherwise in tension with one or more other inner or outer compression members 132, 134. In one embodiment, the internal compression member 132a may be connected to the tension members 133, 135 by at least one of gluing, welding, bonding, adhering, or the like. Although the embodiment shown in fig. 6C depicts the internal compression member 132a corresponding to the electrode and counter electrode structures 151, 152 (i.e., both electrode and counter electrode structures are in tension with one another by being connected to the tensioning members 133, 135), in alternative embodiments, only one of the electrode and/or counter electrode structures is used as the internal compression member 132a, and/or only a portion of the electrode or counter electrode structure 151, 152 may be used as the internal compression member 132a, such as by being adhered to the tensioning members 133, 135. For example, in one embodiment, at least one of the electrode current collector 163 and/or the counter electrode current collector 152, for example, may be used as the internal compression member 132, such as by being adhered to the tension members 133, 135.

Referring again to fig. 4, to complete the manufacture of the secondary battery 100, the battery case 102 is filled with a non-aqueous electrolyte (not shown), and the cover 104 is folded (along fold line 106) and sealed to the upper surface 108. When fully assembled, the sealed secondary battery occupies a volume bounded by its exterior surface (i.e., a displaced volume), the secondary battery housing 102 occupies a volume corresponding to the displaced volume of the battery (including the cover 104) minus its interior volume (i.e., a prismatic volume bounded by the interior surfaces 103A, 103B, 103C, 103D, 103E and the cover 104), and each constraint 130 of the set 110 occupies a volume corresponding to its respective displaced volume. Thus, in combination, the battery housing and restraint occupy no more than 75% of the volume restrained by the outer surface of the battery housing (i.e., the displaced volume of the battery). For example, in one such embodiment, the restraint and battery housing combination occupies no more than 60% of the volume restrained by the outer surface of the battery housing. As a further example, in one such embodiment, the restraint and battery housing combination occupies no more than 45% of the volume restrained by the outer surface of the battery housing. As a further example, in one such embodiment, the restraint and battery housing combination occupies no more than 30% of the volume restrained by the outer surface of the battery housing. As a further example, in one such embodiment, the restraint and battery housing combination occupies no more than 20% of the volume restrained by the outer surface of the battery housing.

For convenience of illustration in fig. 4, the secondary battery 100 includes only one set 110 of electrode assemblies, and the set includes only six electrode assemblies 120. In practice, a secondary battery may include more than one set of electrode assemblies, with each set being disposed laterally with respect to one another (e.g., in opposing directions within the X-Y plane of the cartesian coordinate system of fig. 4), or each set being disposed perpendicularly with respect to one another (e.g., in a direction substantially parallel to the Z-axis of the cartesian coordinate system of fig. 4). Additionally, in each of these embodiments, each of the sets of electrode assemblies may include one or more electrode assemblies. For example, in some embodiments, a secondary battery may include one, two, or more sets of electrode assemblies, each such set including one or more electrode assemblies (e.g., 1,2, 3, 4, 5, 6, 10, 15, or more electrode assemblies within each such set), and when a battery includes two or more such sets, the sets may be disposed laterally or vertically with respect to the electrode assemblies of other sets that include the secondary battery. In each of these various embodiments, each individual electrode assembly may have its own constraint (i.e., a 1: 1 relationship between the electrode assembly and the constraint), two or more electrode assemblies may have a common constraint (i.e., a single constraint for two or more electrode assemblies), or two or more electrode assemblies may share components of the constraint (i.e., two or more electrode assemblies may have common compression and/or tension members).

Referring now to fig. 12A, in one exemplary embodiment, the electrode assembly 120 includes first and second longitudinal end surfaces 121, 122 and side surfaces including sides 123, 124, 125, 126. The electrode assembly 120 further includes a set of electrode structures 151 and a set of counter electrode structures 152 stacked in an electrode stacking direction D parallel to the longitudinal axis a, extending between the opposing first and second longitudinal end surfaces 121, 122. The electrode and counter electrode structures 151, 152 are stacked in an alternating order (e.g., interdigitated) with substantially each member of the electrode set between two members of the counter electrode set, and substantially each member of the counter electrode set between two members of the electrode set. For example, in addition to alternating the first and last electrode or counter electrode structures in the series (series), in one embodiment, each electrode structure in the alternating series is between two counter electrode structures, and each counter electrode structure in the series is between two electrode structures. Additionally, in the hypothetical backplane (e.g., sides 126, 127, respectively), the ratio of the surface area of the non-layered electrode and counter electrode structures to their respective geometric coverage can be at least about 5, at least about 10, at least about 50, at least about 100, or even at least about 500, as previously described.

As shown in fig. 12A, each member 151 of the group of electrode structures is between two members 152 of the group of counter electrode structures with one exception, and each member 152 of the group of counter electrode structures is between two members 151 of the group of electrode structures with one exception. More generally, in one embodiment, the electrode and counter electrode sets each have N members, each of the N-1 electrode set members is between two counter electrode structures, each of the N-1 counter electrode set members is between electrode structures, and N is at least 2. For example, in one embodiment, N is at least 4 (as shown in fig. 4), at least 5, at least 10, at least 25, at least 50, or even at least 100.

Referring now to fig. 12B and 12C, the projection of the members of the electrode and counter electrode sets on the first longitudinal end surface 122 encompasses a first projection area 162, and the projection of the members of the electrode and counter electrode sets on the second longitudinal end surface 124 encompasses a second projection area 164. Generally, the first and second projected areas 162, 164 will generally comprise a substantial portion of the surface area of the first and second longitudinal end surfaces 122, 124, respectively. For example, in one embodiment, the first and second projected areas each comprise at least 50% of the surface area of the first and second longitudinal end surfaces, respectively. As another example, in one such embodiment, the first and second projected areas each comprise at least 75% of the surface area of the first and second longitudinal end surfaces, respectively. As another example, in one such embodiment, the first and second projected areas comprise at least 90% of the surface area of the first and second longitudinal end surfaces, respectively.

The electrodes and components of the counter electrode set comprise electroactive materials capable of absorbing and releasing carrier ions such as lithium, sodium, potassium, calcium, magnesium or aluminium ions. In some embodiments, member 151 of the electrode structure set comprises an anode active electroactive material (sometimes referred to as the negative electrode) and member 152 of the counter electrode structure set comprises a cathode active electroactive material (sometimes referred to as the positive electrode). In other embodiments, member 151 of the electrode structure set comprises a cathodically active electroactive material and member 152 of the counter electrode structure set comprises an anodically active electroactive material. In each of the embodiments and examples described in this paragraph, the negative active material may be a particle aggregate electrode or a monomer electrode.

Exemplary anode active electroactive materials include carbon materials such as graphite and soft or hard carbon, or any of a range of metals, semi-metals, alloys, oxides, and composites capable of alloying with lithium. Specific examples of metals or semimetals that can constitute the anode material include tin, lead, magnesium, aluminum, boron, gallium, silicon, indium, zirconium, germanium, bismuth, cadmium, antimony, silver, zinc, arsenic, hafnium, yttrium, and palladium. In one exemplary embodiment, the anode active material includes aluminum, tin, or silicon, or an oxide thereof, a nitride thereof, a fluoride thereof, or other alloys thereof. In another exemplary embodiment, the anode active material includes silicon or an alloy thereof.

Exemplary cathode active materials include any of a wide range of cathode active materials. For example, for a lithium ion battery, the cathode active material may include a cathode material selected from the group consisting of transition metal oxides, transition metal sulfides, transition metal nitrides, lithium-transition metal oxides, lithium-transition metal sulfides, and lithium-transition metal nitrides, may be selectively used. The transition metal element of these transition metal oxides, transition metal sulfides and transition metal nitrides may include a transition metal element havingMetal elements of the d-shell or f-shell. Specific examples of such metal elements are Sc, Y, lanthanoid, actinoid, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pb, Pt, Cu, Ag and Au. Other cathode active materials include LiCoO₂、LiNi_0.5Mn_1.5O₄、Li(Ni_xCo_yAl₂)O₂、LiFePO₄、Li₂MnO₄、V₂O₅Molybdenum oxysulfide, phosphate, silicate, vanadate, and combinations thereof.

In one embodiment, the anode active material is microstructured to provide a significant void volume fraction to accommodate volume expansion and contraction as lithium ions (or other carrier ions) bind to or leave the anode active material during charge and discharge processes. Typically, the void volume fraction of the negative electrode active material is at least 0.1. However, in general, the void volume fraction of the anode active material is not more than 0.8. For example, in one embodiment, the void volume fraction of the negative electrode active material is from about 0.15 to about 0.75. As another example, in one embodiment, the void volume fraction of the negative electrode active material is about 0.2 to about 0.7. As another example, in one embodiment, the void volume fraction of the negative electrode active material is about 0.25 to about 0.6.

Depending on the composition of the microstructured anode active material and the method of forming the same, the microstructured anode active material may comprise a layer of macroporous, microporous, or mesoporous material, or a combination thereof, such as a combination of micropores and mesopores or a combination of mesopores and macropores. Microporous materials are generally characterized by: pore sizes of less than 10nm, wall sizes of less than 10nm, pore depths of 1-50 microns, and pore morphologies generally characterized by "sponge-like" and irregular appearance, non-smooth walls, and branched pores. Mesoporous materials are generally characterized by: pore sizes of 10-50nm, wall sizes of 10-50nm, pore depths of 1-100 microns, and pore morphologies that are generally characterized by somewhat well-defined branched or dendritic pores. Macroporous materials are generally characterized by: pore sizes greater than 50nm, wall sizes greater than 50nm, pore depths of 1-500 microns, and pore morphologies that can vary, continuous, branched, or dendritic, and smooth or rough walls. Additionally, the void volume may include open or closed voids, or a combination thereof. In one embodiment, the void volume comprises open voids, i.e., the anode active material comprises voids having openings at the side surfaces of the anode active material through which lithium ions (or other carrier ions) can enter or exit the anode active material; for example, lithium ions may enter the negative active material through the void openings after exiting the positive active material. In another embodiment, the void volume comprises closed voids, i.e., the negative active material comprises voids surrounded by the negative active material. In general, open voids may provide a greater interfacial surface area for the carrier ions, while closed voids tend to be less susceptible to solid electrolyte interfaces, each providing space for expansion of the negative active material upon entry of the carrier ions. Thus, in certain embodiments, it is preferred that the negative active material include a combination of open and closed voids.

In one embodiment, the negative active material includes porous aluminum, tin, or silicon or alloys thereof. The porous silicon layer may be formed, for example, by: anodization, etching (e.g., by depositing a noble metal such as gold, platinum, silver, or gold/palladium on a (100) surface of single crystal silicon, and etching the surface with a hydrofluoric acid and hydrogen peroxide mixture), or by other methods known in the art (such as patterned chemical etching). In addition, the porous anode active material will typically have a porosity of at least about 0.1 but less than 0.8 and a thickness of about 1 to about 100 microns. For example, in one embodiment, the negative active material includes porous silicon, has a thickness of about 5 to about 100 microns, and has a porosity of about 0.15 to about 0.75. As another example, in one embodiment, the negative active material includes porous silicon, has a thickness of about 10 to about 80 microns, and has a porosity of about 0.15 to about 0.7. As another example, in one embodiment, the negative active material includes porous silicon, has a thickness of about 20 to about 50 microns, and has a porosity of about 0.25 to about 0.6. As another example, in one embodiment, the negative active material comprises a porous silicon alloy (such as nickel silicide), has a thickness of about 5 to about 100 microns, and has a porosity of about 0.15 to about 0.75.

In another embodiment, the negative active material includes fibers of aluminum, tin, or silicon, or alloys thereof. The individual fibers may have a diameter (thickness dimension) of about 5nm to about 10,000nm and a length generally corresponding to the thickness of the negative electrode active material. The silicon fibers (nanowires) can be formed by the following method: for example by chemical vapor deposition or other techniques known in the art, such as Vapor Liquid Solid (VLS) growth and Solid Liquid Solid (SLS) growth. Further, the negative active material will typically have a porosity of at least about 0.1 but less than 0.8 and a thickness of about 1 to about 200 microns. For example, in one embodiment, the negative active material includes silicon nanowires, has a thickness of about 5 to about 100 microns, and has a porosity of about 0.15 to about 0.75. As another example, in one embodiment, the negative active material includes silicon nanowires, has a thickness of about 10 to about 80 microns, and has a porosity of about 0.15 to about 0.7. As another example, in one embodiment, the negative active material includes silicon nanowires, has a thickness of about 20 to about 50 microns, and has a porosity of about 0.25 to about 0.6. As another example, in one embodiment, the negative active material includes nanowires of a silicon alloy (such as nickel silicide), has a thickness of about 5 to about 100 microns, and has a porosity of about 0.15 to about 0.75.

In one embodiment, the components of the electrode group include an electrode active material layer, an electrode current collector, and an electrode stem supporting the electrode active material layer and the electrode current collector. Similarly, in one embodiment, the components of the counter electrode group include a counter electrode active material layer, a counter electrode current collector, and a counter electrode stem supporting the counter electrode active material layer and the counter electrode current collector.

In one embodiment, each member of the electrode set has a bottom, a top, and a longitudinal axis (A) extending from the bottom to the top thereof_E) And a longitudinal axis (A)_E) In a direction generally perpendicular to the direction of advancement of the alternating sequence of electrode structures and counter electrode structures. In addition, each member of the electrode assembly has a longitudinal axis (A)_E) MeasuringLength (L) of_E) Width (W) measured in the direction of advance of the electrode structure and counter-electrode structure in alternating sequence_E) And a length (L) perpendicular to the measurement_E) And width (W)_E) Height (H) measured in each direction of the_E). Each member of the electrode set also has a perimeter (P)_E) The perimeter corresponds to the sum of the lengths of the projected sides of the electrodes in a plane perpendicular to their longitudinal axis.

Length (L) of the members of the electrode group_E) Will vary depending on the energy storage device and its intended use. Typically, however, the members of the electrode assembly will typically have a length (L) in the range of about 5mm to about 500mm_E). For example, in one such embodiment, the members of the electrode set have a length (L) of about 10mm to about 250mm_E). As another example, in one such embodiment, the members of the electrode set have a length (L) of about 25mm to about 100mm_E)。

Width (W) of members of the electrode group_E) Will also vary depending on the energy storage device and its intended use. Typically, however, each member of the electrode set will typically have a width (W) in the range of about 0.01mm to 2.5mm_E). For example, in one embodiment, the width (W) of each member of the electrode set_E) Will be in the range of about 0.025mm to about 2 mm. As another example, in one embodiment, the width (W) of each member of the electrode set_E) Will be in the range of about 0.05mm to about 1 mm.

Height (H) of the members of the electrode group_E) Will also vary depending on the energy storage device and its intended use. Typically, however, the components of the electrode assembly will typically have a height (H) in the range of about 0.05mm to about 10mm_E). For example, in one embodiment, the height (H) of each member of the electrode set_E) Will be in the range of about 0.05mm to about 5 mm. As another example, in one embodiment, the height (H) of each member of the electrode set_E) Will be in the range of about 0.1mm to about 1 mm.

Perimeter (P) of members of the electrode group_E) Will similarly vary depending on the energy storage device and its intended use. However, the device is not suitable for use in a kitchenIn general, however, the components of the electrode assembly will typically have a circumference (P) in the range of about 0.025mm to about 25mm_E). For example, in one embodiment, the perimeter (P) of each member of the electrode set_E) Will be in the range of about 0.1mm to about 15 mm. As another example, in one embodiment, the perimeter (P) of each member of the electrode set_E) Will be in the range of about 0.5mm to about 10 mm.

Typically, the members of the electrode assembly have a width (W) substantially greater than the width (W) thereof_E) And its height (H)_E) Length (L) of each of_E). For example, in one embodiment, for each member of the electrode set, L_EAnd W_EAnd H_EIs at least 5:1 (i.e., respectively, L_EAnd W_EIs at least 5:1, respectively, L_EAnd H_EIs at least 5: 1). As another example, in one embodiment, L_EAnd W_EAnd H_EAt least 10: 1. As another example, in one embodiment, L_EAnd W_EAnd H_EAt least 15: 1. As another example, in one embodiment, L is for each member of the electrode set_EAnd W_EAnd H_EAt least 20: 1.

In addition, it is generally preferred that the members of the electrode assembly have a circumference (P) substantially greater than that of the electrode assembly_E) Length (L) of_E) (ii) a For example, in one embodiment, for each member of the electrode set, L_EAnd P_EAre each at least 1.25: 1. As another example, in one embodiment, L is for each member of the electrode set_EAnd P_EAre each at least 2.5: 1. As another example, in one embodiment, L is for each member of the electrode set_EAnd P_EAre each at least 3.75: 1.

In one embodiment, the height (H) of the members of the electrode set_E) And width (W)_E) Are each at least 0.4: 1. For example, in one embodiment, for each construct of the set of electrodesMember H_EAnd W_EWill be at least 2:1, respectively. As another example, in one embodiment, H_EAnd W_EWill be at least 10:1, respectively. As another example, in one embodiment, H_EAnd W_EWill be at least 20:1, respectively. However, in general, H_EAnd W_EAre generally less than 1000: 1. for example, in one embodiment, H_EAnd W_EWill be less than 500:1, respectively. As another example, in one embodiment, H_EAnd W_EWill be less than 100:1, respectively. As another example, in one embodiment, H_EAnd W_EWill be less than 10:1, respectively. As another example, in one embodiment, for each member of the electrode set, H_EAnd W_EWill range from about 2:1 to about 100:1, respectively.

Each member of the counter electrode group has a bottom, a top and a longitudinal axis (A) extending from the bottom to the top thereof_CE) And a longitudinal axis (A)_CE) In a direction generally perpendicular to the direction of advancement of the alternating sequence of electrode structures and counter electrode structures. In addition, each member of the counter electrode group has a longitudinal axis (A)_CE) Measured length (L)_CE) Width (W) measured in the direction of advance of the electrode structure and counter-electrode structure in alternating sequence_CE) And a length (L) perpendicular to the measurement_CE) And width (W)_CE) Height (H) measured in each direction of the_CE). Each member of the counter electrode group also has a perimeter (P)_CE) The perimeter corresponds to the sum of the lengths of the sides of the projection of the counter electrode in a plane perpendicular to its longitudinal axis.

Length (L) of member of counter electrode group_CE) Will vary depending on the energy storage device and its intended use. Typically, however, each member of the counter electrode set will typically have a length (L) in the range of about 5mm to about 500mm_CE). For example, in one such embodiment, each member of the counter electrode set has a length (L) of about 10mm to about 250mm_CE). As another example, in one such embodiment,each member of the counter electrode set has a length (L) of about 25mm to about 100mm_CE)。

Width (W) of members of counter electrode group_CE) Will also vary depending on the energy storage device and its intended use. However, typically, the members of the counter electrode set will typically have a width (W) in the range of about 0.01mm to 2.5mm_CE). For example, in one embodiment, the width (W) of each member of the electrode set_CE) Will be in the range of about 0.025mm to about 2 mm. As another example, in one embodiment, the width (W) of each member of the electrode set is measured_CE) Will be in the range of about 0.05mm to about 1 mm.

Height (H) of members of counter electrode group_CE) Will also vary depending on the energy storage device and its intended use. In general, however, the members of the counter electrode set will typically have a height (H) in the range of about 0.05mm to about 10mm_CE). For example, in one embodiment, the height (H) of each member of the electrode set_CE) Will be in the range of about 0.05mm to about 5 mm. As another example, in one embodiment, the height (H) of each member of the electrode set is measured_CE) Will be in the range of about 0.1mm to about 1 mm.

Perimeter (P) of members of the counter electrode group_CE) Will also vary depending on the energy storage device and its intended use. In general, however, the members of the counter electrode set will typically have a circumference (P) in the range of about 0.025mm to about 25mm_CE). For example, in one embodiment, the perimeter (P) of each member of the electrode set_CE) Will be in the range of about 0.1mm to about 15 mm. As another example, in one embodiment, the perimeter (P) of each member of the electrode set is measured_CE) Will be in the range of about 0.5mm to about 10 mm.

Typically, each member of the counter electrode set has a width (W) substantially greater than the width (W)_CE) And is substantially greater than its height (H)_CE) Length (L) of_CE). For example, in one embodiment, L is for each member of the counter electrode set_CEAnd W_CEAnd H_CEIs at least 5:1 (i.e., respectively, L_CEAnd W_CEIs at least 5:1, respectively, L_CEAnd H_CEIs at least 5: 1). As another example, in one embodiment, L is for each member of the counter electrode set_CEAnd W_CEAnd H_CEAt least 10: 1. As another example, in one embodiment, L is for each member of the counter electrode set_CEAnd W_CEAnd H_CEAt least 15: 1. As another example, in one embodiment, L is for each member of the counter electrode set_CEAnd W_CEAnd H_CEAt least 20: 1.

In addition, it is generally preferred that the members of the counter electrode set have a circumference (P) substantially greater than that of the counter electrode set_CE) Length (L) of_CE) (ii) a For example, in one embodiment, L is for each member of the counter electrode set_CEAnd P_CEAre each at least 1.25: 1. As another example, in one embodiment, L is for each member of the counter electrode set_CEAnd P_CEAre each at least 2.5: 1. As another example, in one embodiment, L is for each member of the counter electrode set_CEAnd P_CEAre each at least 3.75: 1.

In one embodiment, the height (H) of the members of the counter electrode set_CE) And width (W)_CE) Are each at least 0.4: 1. For example, in one embodiment, for each member of the counter electrode set, H_CEAnd W_CEWill be at least 2:1, respectively. As another example, in one embodiment, H is for each member of the counter electrode set_CEAnd W_CEWill be at least 10:1, respectively. As another example, in one embodiment, H is for each member of the counter electrode set_CEAnd W_CEWill be at least 20:1, respectively. However, in general, for each member of the electrode set, H_CEAnd W_CEWill generally be less than 1000:1, respectively. For example, in one embodiment, for each member of the counter electrode set, H_CEAnd W_CEWill be less than 500:1, respectively. AsAs another example, in one embodiment, H_CEAnd W_CEWill be less than 100:1, respectively. As another example, in one embodiment, H_CEAnd W_CEWill be less than 10:1, respectively. As another example, in one embodiment, H is for each member of the counter electrode set_CEAnd W_CEWill range from about 2:1 to about 100:1, respectively.

Referring again to fig. 12A, an electrically insulating membrane layer 153 surrounds and electrically isolates each member 151 of the electrode structure set from each member 152 of the counter electrode structure set. The electrically insulating separator layer 153 will typically comprise a microporous separator material permeable to the non-aqueous electrolyte; for example, in one embodiment, the microporous membrane material comprises pores having a diameter of at least 50 angstroms, more typically a diameter in the range of about 2500 angstroms, with a porosity in the range of about 25% to about 75%, more typically in the range of about 35-55%. In addition, the microporous separator material is impregnated with a non-aqueous electrolyte to allow carrier ions to conduct between the electrode and an adjacent member of the counter electrode set. In one embodiment, for example, and ignoring the porosity of the microporous separator material, for ion exchange during charging or discharging, at least 70 vol% of the electrically insulating separator material layer 153 between the member 151 of the electrode structure set and the nearest member 152 (i.e., the "adjacent pair") of the counter electrode structure set is microporous separator material; in other words, the microporous separator material constitutes at least 70 vol% of the electrically insulating material between the member 151 of the electrode structure group and the nearest member 152 of the counter electrode structure group. As another example, in one embodiment, the microporous membrane material constitutes at least 75 vol% of the electrically insulating membrane material layer between adjacent pairs of members 151 and 152 of the electrode structure set and counter electrode structure set, respectively, regardless of the porosity of the microporous membrane material. As another example, in one embodiment, and ignoring the porosity of the microporous membrane material, the microporous membrane material constitutes at least 80 vol% of the electrically insulating membrane material layer between adjacent pairs of members 151 and 152 of the electrode structure set and counter electrode structure set, respectively. As another example, in one embodiment, and ignoring the porosity of the microporous membrane material, the microporous membrane material constitutes at least 85 vol% of the electrically insulating membrane material layer between adjacent pairs of members 151 and 152 of the electrode structure set and counter electrode structure set, respectively. As another example, in one embodiment, and ignoring the porosity of the microporous membrane material, the microporous membrane material constitutes at least 90 vol% of the electrically insulating membrane material layer between adjacent pairs of members 151 and 152 of the electrode structure set and counter electrode structure set, respectively. As another example, in one embodiment, and ignoring the porosity of the microporous membrane material, the microporous membrane material constitutes at least 95 vol% of the electrically insulating membrane material layer between adjacent pairs of members 151 and 152 of the electrode structure set and counter electrode structure set, respectively. As another example, in one embodiment, and ignoring the porosity of the microporous membrane material, the microporous membrane material constitutes at least 99 vol% of the electrically insulating membrane material layer between adjacent pairs of members 151 and 152 of the electrode structure set and counter electrode structure set, respectively.

In one embodiment, the microporous separator material comprises a particulate material and a binder, and has a porosity (void fraction) of at least about 20 vol%. The pores of the microporous membrane material will have a diameter of at least 50 angstroms and will typically fall within the range of about 250 to 2500 angstroms. The microporous separator material will typically have a porosity of less than about 75%. In one embodiment, the microporous separator material has a porosity (void fraction) of at least about 25 vol%. In one embodiment, the microporous separator material will have a porosity of about 35-55%.

The binder for the microporous separator material may be selected from a wide range of inorganic or polymeric materials. For example, in one embodiment, the binder is an inorganic material selected from the group consisting of: silicates, phosphates, aluminates, aluminosilicates, and hydroxides (such as magnesium hydroxide, calcium hydroxide, and the like). For example, in one embodiment, the binder is a fluoropolymer derived from monomers comprising vinylidene fluoride, hexafluoropropylene, tetrafluoropropene, and the like. In another embodiment, the adhesive is a polyolefin, such as polyethylene, polypropylene, or polybutylene, having any range of different molecular weights and densities. In another embodiment, the adhesive is selected from the group comprising: ethylene-diene-propylene terpolymers, polystyrene, polymethyl methacrylate, polyethylene glycol, polyvinyl acetate, polyvinyl butyral, polyacetal and polyethylene glycol diacrylate. In another embodiment, the adhesive is selected from the group comprising: methylcellulose, carboxymethylcellulose, styrene rubber, butadiene rubber, styrene-butadiene rubber, isoprene rubber, polyacrylamide, polyvinyl ether, polyacrylic acid, polymethacrylic acid, and polyethylene oxide. In another embodiment, the adhesive is selected from the group comprising: acrylates, styrenes, epoxies and silicones. In another embodiment, the binder is a copolymer or blend of two or more of the foregoing polymers.

The particulate material comprised by the microporous separator material may also be selected from a wide range of materials. Typically, such materials have relatively low electronic and ionic conductivity at operating temperatures and do not corrode at the operating voltages of the battery electrodes or current collectors in contact with the microporous separator material. For example, in one embodiment, the particulate material has a particle size of less than 1 x 10^-4S/cm of conductivity of the carrier ion (e.g., lithium). As another example, in one embodiment, the particulate material has a particle size of less than 1 x 10^-5Conductivity of carrier ion of S/cm. As another example, in one embodiment, the particulate material has a particle size of less than 1 × 10^-6Conductivity of carrier ion of S/cm. Exemplary particulate materials include particulate polyethylene, polypropylene, TiO₂-a polymer composite, silica aerogel, fumed silica, silica gel, silica hydrogel, silica xerogel, silica sol, colloidal silica, alumina, titania, magnesia, kaolin, talc, diatomaceous earth, calcium silicate, aluminum silicate, calcium carbonate, magnesium carbonate, or combinations thereof. For example, in one embodiment, the particulate material comprises a material such as TiO₂、SiO₂、Al₂O₃、GeO₂、B₂O₃、Bi₂O₃、BaO、ZnO、ZrO₂、BN、Si₃N₄、Ge₃N₄See, for example, pZhang, "Battery Separators" Chemical Reviews 2004,104, 4419-4462. In one embodiment, the particulate material will have an average particle size of about 20nm to 2 microns, more typically 200nm to 1.5 microns. In one embodiment, the particulate material will have an average particle size of about 500nm to 1 micron.

In an alternative embodiment, the particulate material comprised by the microporous separator material may be bonded by techniques such as sintering, bonding, curing, etc., while maintaining a desired porosity for electrolyte to enter to provide ionic conductivity for the function of the battery.

Microporous separator materials can be deposited, for example, by electrophoretic deposition of particulate separator materials in which the particles are bound by surface energy (such as electrostatic attraction or van der waals forces), slurry deposition (including spin or spray coating) of particulate separator materials, screen printing, dip coating, and electrostatic spray deposition. The binder may be included in the deposition process; for example, the particulate material may be slurry deposited with a dissolved binder that precipitates upon evaporation of the solvent, electrophoretically deposited in the presence of the dissolved binder material, or co-electrophoretically deposited with the binder and insulating particles, and the like. Alternatively or additionally, the binder may be added after the particles are deposited into or onto the electrode structure; for example, the particulate material may be dispersed in an organic binder solution and dip-coated or spray-coated, and then the binder material dried, melted, or cross-linked to provide adhesive strength.

In the assembled energy storage device, the microporous separator material is impregnated with a non-aqueous electrolyte suitable for use as an electrolyte for a secondary battery. Generally, the nonaqueous electrolyte contains a lithium salt dissolved in an organic solvent. Exemplary lithium salts include inorganic lithium salts, such as LiClO₄、LiBF₄、LiPF₆、LiAsF₆LiCl and LiBr; and organic lithium salts such as LiB (C)₆H₅)₄、LiN(SO₂CF₃)₂、LiN(SO₂CF₃)₃、LiNSO₂CF₃、LiNSO₂CF₅、LiNSO₂C₄F₉、LiNSO₂C₅F₁₁、LiNSO₂C₆F₁₃And LiNSO₂C₇F₁₅. Exemplary organic solvents that dissolve the lithium salt include cyclic esters, chain esters, cyclic ethers, and chain ethers. Specific examples of the cyclic ester include propylene carbonate, butylene carbonate, γ -butyrolactone, vinylene carbonate, 2-methyl- γ -butyrolactone, acetyl- γ -butyrolactone and γ -valerolactone. Specific examples of the chain ester include dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dipropyl carbonate, ethyl methyl carbonate, butyl methyl carbonate, propyl methyl carbonate, butyl ethyl carbonate, propyl ethyl carbonate, butyl propyl carbonate, alkyl propionate, dialkyl malonate, and alkyl acetate. Specific examples of the cyclic ether include tetrahydrofuran, alkyltetrahydrofuran, dialkyltetrahydrofuran, alkoxytetrahydrofuran, dialkoxytetrahydrofuran, 1, 3-dioxolane, alkyl-1, 3-dioxolane, and 1, 4-dioxolane. Specific examples of the chain ether include 1, 2-dimethoxyethane, 1, 2-diethoxyethane, diethyl ether, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether, and tetraethylene glycol dialkyl ether.

Referring again to fig. 12A, 12B and 12C, regions 122, 124 of the longitudinal end surfaces of the electrode assembly that coincide with projections of the electrodes onto the longitudinal end surfaces 162, 164 and members of the counter electrode set (i.e., "projected surface regions"), respectively, will be subjected to significant compressive loads applied by the restraint 130 (see fig. 4). For example, in one embodiment, the regions of the longitudinal end surfaces of the electrode assembly coinciding with projections onto the electrodes on the longitudinal end surfaces and members of the counter electrode set will each be subjected to a compressive load of at least 0.7kPa (averaged over the surface area of each of the first and second projected surface regions, respectively). As another example, in one such embodiment, the regions of the longitudinal end surfaces of the electrode assembly that coincide with projections to the electrodes on the longitudinal end surfaces and members of the counter electrode set will each be subjected to a compressive load of at least 1.75kPa (averaged over the surface area of each of the first and second projected surface regions, respectively). As another example, in one such embodiment, the regions of the longitudinal end surfaces of the electrode assembly that coincide with projections to the electrodes on the longitudinal end surfaces and members of the counter electrode set will each be subjected to a compressive load of at least 2.8kPa (averaged over the surface area of each of the first and second projected surface regions, respectively). As another example, in one such embodiment, the regions of the longitudinal end surfaces of the electrode assembly coinciding with projections onto the electrodes on the longitudinal end surfaces and members of the counter electrode set will each be subjected to a compressive load of at least 3.5kPa (averaged over the surface area of each of the first and second projected surface regions, respectively). As another example, in one such embodiment, the regions of the longitudinal end surfaces of the electrode assembly coinciding with projections onto the electrodes on the longitudinal end surfaces and members of the counter electrode set will each be subjected to a compressive load of at least 5.25kPa (averaged over the surface area of each of the first and second projected surface regions, respectively). As another example, in one such embodiment, the regions of the longitudinal end surfaces of the electrode assembly that coincide with projections to the electrodes on the longitudinal end surfaces and members of the counter electrode set will each be subjected to a compressive load of at least 7kPa (averaged over the surface area of each of the first and second projected surface regions, respectively). As another example, in one such embodiment, the regions of the longitudinal end surfaces of the electrode assembly that coincide with projections to the electrodes on the longitudinal end surfaces and members of the counter electrode set will each be subjected to a compressive load of at least 8.75kPa (averaged over the surface area of each of the first and second projected surface regions, respectively). However, typically, the regions of the longitudinal end surfaces of the electrode assembly coinciding with projections onto the electrodes on the longitudinal end surfaces and members of the counter electrode set will each be subjected to a compressive load of no more than about 10kPa (averaged over the surface area of each of the first and second projected surface regions, respectively). In each of the foregoing exemplary embodiments, the longitudinal end surfaces of the secondary battery of the present disclosure will experience such a compressive load when the battery is charged to at least about 80% of its rated capacity.

In certain embodiments, substantially the entire longitudinal end surface of the electrode assembly will be subjected to significant compressive loads (and not necessarily only the first and second projected surface areas). For example, in some embodiments, typically, each of the longitudinal end surfaces of the electrode assembly will be subjected to a compressive load of at least 0.7kPa (averaged over the total surface area of each of the longitudinal end surfaces, respectively). For example, in one embodiment, each of the longitudinal end surfaces of the electrode assembly will be subjected to a compressive load (averaged over the total surface area of each of the longitudinal end surfaces, respectively) of at least 1.75 kPa. As another example, in one such embodiment, each of the longitudinal end surfaces of the electrode assembly will be subjected to a compressive load (averaged over the total surface area of each of the longitudinal end surfaces, respectively) of at least 2.8 kPa. As another example, in one such embodiment, each of the longitudinal end surfaces of the electrode assembly will be subjected to a compressive load (averaged over the total surface area of each of the longitudinal end surfaces, respectively) of at least 3.5 kPa. As another example, in one such embodiment, each of the longitudinal end surfaces of the electrode assembly will be subjected to a compressive load (averaged over the total surface area of each of the longitudinal end surfaces, respectively) of at least 5.25 kPa. As another example, in one such embodiment, each of the longitudinal end surfaces of the electrode assembly will be subjected to a compressive load of at least 7kPa (averaged over the total face area of each of the longitudinal end surfaces, respectively). As another example, in one such embodiment, each of the longitudinal end surfaces of the electrode assembly will be subjected to a compressive load (averaged over the total surface area of each of the longitudinal end surfaces, respectively) of at least 8.75 kPa. However, typically, the longitudinal end surfaces of the electrode assembly will be subjected to a compressive load (averaged over the total surface area of each of the longitudinal end surfaces, respectively) of no greater than about 10 kPa. In each of the foregoing exemplary embodiments, the longitudinal end surfaces of the electrode assembly will experience such a compressive load when the battery is charged to at least about 80% of its rated capacity.

In one embodiment, each of the first and second longitudinal end surfaces of the electrode assembly is subjected to a compressive load of at least 100 psi. For example, in one embodiment, each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 200 psi. As another example, in one embodiment, each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 300 psi. As another example, in one embodiment, each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 400 psi. As yet another example, in one embodiment, each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 500 psi. As another example, in one embodiment, each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 600 psi. As yet another example, in one embodiment, each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 700 psi. As yet another example, in one embodiment, each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 800 psi. As another example, in one embodiment, each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 900 psi. In yet another example, each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 1000 psi.

Referring again to fig. 4 and 5A, 5B, 5C and 5D, and in accordance with an aspect of the present disclosure, the tensioning members 133, 135 are preferably relatively close to the side surfaces to inhibit buckling of the electrode assembly in response to compressive forces applied to the longitudinal end surfaces. In the embodiment shown in fig. 5A-5D, for example, the tensioning members 133, 135 contact the sides 123, 125, respectively. However, in other embodiments, there may be a gap between the tension members and the side surfaces. However, in general, the distance between the take-up member and the side surface of the electrode assembly is less than 50% of the minimum feret diameter of the electrode assembly, which is measured in the same direction as the distance between the take-up member and the side surface of the electrode assembly. As another example, in one such embodiment, the distance between the take-up member and the side surface of the electrode assembly is less than 40% of the minimum feret diameter of the electrode assembly, where the feret diameter is measured in the same direction as the distance between the take-up member and the side surface of the electrode assembly. As another example, in one such embodiment, the distance between the take-up member and the side surface of the electrode assembly is less than 30% of the minimum feret diameter of the electrode assembly, where the feret diameter is measured in the same direction as the distance between the take-up member and the side surface of the electrode assembly. As another example, in one such embodiment, the distance between the take-up member and the side surface of the electrode assembly is less than 20% of the minimum feret diameter of the electrode assembly, where the feret diameter is measured in the same direction as the distance between the take-up member and the side surface of the electrode assembly. As another example, in one such embodiment, the distance between the take-up member and the side surface of the electrode assembly is less than 10% of the minimum feret diameter of the electrode assembly, where the feret diameter is measured in the same direction as the distance between the take-up member and the side surface of the electrode assembly. As another example, in one such embodiment, the distance between the take-up member and the side surface of the electrode assembly is less than 5% of the minimum feret diameter of the electrode assembly, where the feret diameter is measured in the same direction as the distance between the take-up member and the side surface of the electrode assembly.

Referring now to fig. 7, an exploded view of an alternate embodiment of the secondary battery of the present disclosure may be seen, generally indicated at 100. The secondary battery includes a battery case 102 and a set 110 of electrode assemblies 120 within the battery case 102, each of the electrode assemblies having a first longitudinal end surface 122, an opposing second longitudinal end surface 124 (separated from the first longitudinal end surface 122 along a longitudinal axis (not shown) parallel to the imaginary cartesian coordinate system "Y-axis" of fig. 7), and side surfaces including sides 123, 125, 126, 127 (see fig. 4). In contrast to the embodiment shown in fig. 4, in this embodiment, the individual constraints 130 exert a compressive force on the first and second longitudinal surfaces of each of the electrode assemblies of the set 110. As previously described, the combined surface area of the opposing first and second longitudinal end surfaces of each of the electrode assemblies within the set 110 is less than 50% of the total surface area of each of the electrode assemblies within the set, respectively. The tensioning members of the restraint 130 tend to pull the compression members toward each other, thereby applying a compressive force to each of the opposing first and second longitudinal end surfaces of each electrode assembly within the collection 110, which in turn inhibits expansion of each electrode assembly within the collection 110 in a longitudinal direction (which coincides with the electrode stacking direction of each electrode assembly as described herein before). In addition, after the battery is formed, a pressure is applied on each electrode assembly constrained within the set 110 of longitudinal directions (i.e., electrode stacking directions), which exceeds a pressure maintained on each corresponding electrode assembly in any one of two directions perpendicular to each other and to the longitudinal directions.

Referring now to fig. 8, 9, 10A and 10B, in an alternative embodiment, the constraint 130 is formed by the sheet 107 including the slot 109, the connection region 111 and the fold region 113. To form the restraint, the sheet 107 is simply wrapped around the electrode structure 120 (shown in fig. 9 without the electrode structure 120), folded along the fold region 113, and the overlapping edges 115, 117 are welded, glued, or otherwise secured to one another to form the restraint including the compression members 132, 134 (compression member 134 which includes the overlapping edges 115, 177 once secured to one another) and the tension members 133, 135. In one such embodiment, the constraint 130 is stretched in the stacking direction D to place the attachment region 111 under tension, which in turn results in a compressive force being applied to the longitudinal end surfaces 122, 124. In an alternative embodiment, instead of stretching the connection region 111 to place it in tension, the connection region is pre-tensioned prior to installation over the electrode assembly. In another alternative embodiment, the connection region 111 is not initially in tension when installed over the electrode assembly, but rather the formation of the cell causes the electrode assembly to expand and induce tension in the connection tension member (i.e., self-tension).

Referring now to fig. 11A and 11B, in an alternative embodiment, constraint 130 includes one or more serpentine tension members 121 in addition to slot 109 and connection region 111. The serpentine tensioning member 121 provides a second tensioning force in those embodiments, wherein the force is greater during formation than during cycling. In such embodiments, the straight members provide greater resistance and yield during formation, while the serpentine tensioning members apply less tension during cycling. As previously described, constraints 130 may be formed by: the sheet 107 is wrapped around the electrode structure 120, folded along the fold region 113, and the overlapping edges 115, 117 are secured (shown in fig. 11A and 11B without the electrode structure 20). When the sheet 107 is wrapped around the electrode structure, the constraint 130 is stretched in the stacking direction D to place the connection region 111 and the serpentine tensioning member 121 under tension, which in turn exerts a compressive force on the electrode structure 120 in the stacking direction D.

Generally, constraints with high strength and stiffness can inhibit rapid growth of the electrode assembly during cell formation, while constraints with much lower strength and stiffness allow for changes in the volume of the electrode assembly due to variations in lithiation encountered at different states of charge. In addition, constraints with lower stiffness and higher preload (or start-up load) help control the resistance of the cell by maintaining a minimum force between the cathode and anode. One way to address these competing needs according to one embodiment of the present disclosure is to construct constraints from two components. These components may be made of any of (i) similar materials with different geometries or (ii) materials with different elastic moduli and the same geometry, (iii) some combination of elastic moduli and geometric properties to achieve the desired stiffness. In both cases, the first component ("element 1") is designed with a higher stiffness (material or geometric drive) than the second component ("element 2") and deforms elastically and then plastically, but does not crack under load, which it experiences during cell formation. The element 2 will preferably only deform elastically. In both cases, the first element should prevent the second element from displacing more than itself by enveloping or otherwise supporting the second element.

In one embodiment, the constraint comprises an elastically deformable material located between the longitudinal surface of the electrode assembly and the compression member. In this embodiment, the elastically deformable material elastically deforms to accommodate the expansion of the electrode and elastically recovers to its original thickness and shape as the electrode contracts. As a result, as the electrode and/or the counter electrode expand and contract during the cycle of the secondary battery, a minimum force may be maintained on the electrode assembly in the longitudinal direction.

Referring now to FIG. 16, in one exemplary embodiment, the constraint 130 includes first and second elements 136, 137. In this embodiment, compression member 132 includes compression regions 132A, 132B of first and second elements 136, 137, respectively, overlying longitudinal end surface 122, and compression member 134 includes compression regions 134A and 134B of first and second elements 136, 137, respectively, overlying longitudinal end surface 124. In addition, tension member 133 includes tension member regions 133A, 133B of first and second elements 136, 137, respectively, that overlie side 123, and tension member 135 includes tension member regions 135A and 135B of first and second elements 136, 137, respectively, that flank 125. In this exemplary embodiment, the first element 136 serves to limit the maximum growth of the electrode assembly during cell formation or cell cycling, while the element 137 serves to maintain a preload in the direction of the electrode stacking direction D during a discharge state. In the exemplary embodiment, element 136 is not preloaded (no force is applied on the electrode assembly) prior to formation. The element 137 is preloaded onto the electrode assembly to exert a compressive force on the first and second longitudinal end surfaces 122, 124. As the electrode assembly expands (e.g., during the charging step, the silicon-containing anode expands upon carrier ion binding), the force on the element 136 increases rapidly due to its higher stiffness, while the force on the lower stiffness element 137 increases slowly due to its displacement being limited by the element 136. Above a certain force, the element 136 will yield or move from elastic to plastic (permanent) deformation, while the element 137 remains in the elastic range. As the force continues to rise, the length of the element 136 permanently increases. Thereafter, when the force is reduced to a small value (e.g., during the discharge step, the silicon-containing anode contracts as the carrier ions pull out), the element 136 has been permanently deformed and may no longer contact the electrode assembly 120, and the element 137 may return to near its initial preload level.

Referring now to fig. 13, in an alternative embodiment, a secondary battery 100 includes a battery case 102 and a collection of electrode assemblies 120 within the battery case 102. As previously described, each of the electrode assemblies has a first longitudinal end surface and an opposite second longitudinal end surface spaced apart along the longitudinal axis, and side surfaces surrounding the longitudinal axis (see fig. 4 and 12A). In addition, the set has an associated constraint 130, the constraint 130 including a top constraint member 130T and a bottom constraint member 130B to inhibit expansion in the electrode stacking direction D of each of the electrode assemblies within the set. Top and bottom constraining members 130T, 130B include interlocking tabs (tab)132D, 132C, respectively, which in combination constitute compression member 132. Top and bottom binding members 130T and 130B each include interlocking tabs that, in combination, form compression member 134 (not shown). As in other embodiments, each of the compression members applies a compressive force to the opposing first and second longitudinal end surfaces, and the tensioning members include the slots 109 and the connection regions 111 as previously described.

Referring now to fig. 14, in an alternative embodiment, a secondary battery 100 includes a battery case 102, a set of electrode assemblies (not shown) within the battery case 102, and an associated constraint 130 to inhibit swelling of each of the electrode assemblies within the set in the electrode stacking direction. The constraint 130 includes first and second casings 130R, 130L that respectively enclose first and second longitudinal halves of a set of electrode assemblies. As in other embodiments, a first compression member 132 comprising elements 132E and 132F overlies a first longitudinal end surface (not shown) of the electrode assembly within the stack, a second compression member (not shown) overlies a second longitudinal end surface (not shown) of the electrode assembly within the stack, and a tension member overlies a side surface of the electrode assembly. As in other embodiments, each of the compression members applies a compressive force to the opposing first and second longitudinal end surfaces, and the tensioning members include the slots 109 and the connection regions 111 as previously described.

Referring now to fig. 15, in an alternative embodiment, a secondary battery 100 includes a battery case 102, a set of electrode assemblies 120 within the battery case 102, and an associated constraint 130 to inhibit swelling of each of the electrode assemblies within the set in the electrode stacking direction. The restraint 130 includes a series of bands 151 surrounding each electrode assembly and a cap 153 interposed between the bands 151 and first and second longitudinal end surfaces (not shown) of each electrode assembly 120 in the set. In this embodiment, the portion of the band overlying the longitudinal end surface and the cap constitute the compression member of the present disclosure, and the portion of the band overlying the side surface of the electrode assembly constitutes the tension member. As in other embodiments, each of the compression members applies a compressive force to the opposing first and second longitudinal end surfaces, as previously described.

In other embodiments numbered 1-122 below, aspects of the present disclosure include:

example 1:

a secondary battery for cycling between a charged state and a discharged state, the secondary battery comprising a battery case, an electrode assembly and a non-aqueous liquid electrolyte within the battery case, and a constraint which maintains pressure on the electrode assembly as the secondary battery cycles between the charged state and the discharged state, the electrode assembly comprising a set of electrode structures, a set of counter electrode structures and an electrically insulating microporous separator material between the electrodes and members of the counter electrode assembly, wherein the electrode structure comprises a porous membrane material and the electrode assembly comprises a porous membrane material which is arranged to be porous and to support the electrode assembly in a gas-tight manner

The electrode assembly has opposite first and second longitudinal end surfaces spaced apart along the longitudinal axis, and side surfaces surrounding the longitudinal axis and connecting the first and second longitudinal end surfaces, the first and second longitudinal end surfaces having a surface area less than 33% of a surface area of the electrode assembly,

the members of the electrode group and the members of the counter electrode group are arranged in an alternating order in a stacking direction parallel to the longitudinal axis within the electrode assembly,

a projection of the electrode group and the member of the counter electrode group on the first longitudinal surface encloses a first projection area, and a projection of the electrode group and the member of the counter electrode group on the second longitudinal surface encloses a second projection area,

the constraint includes first and second compression members overlying the first and second projected areas, respectively, the compression members being connected by a tension member overlying a side surface of the electrode assembly and pulling the compression members toward each other, an

The pressure maintained on the electrode assembly in the stacking direction is restrained, which exceeds the pressure maintained on the electrode assembly in each of two directions perpendicular to each other and to the stacking direction.

Example 2:

the secondary battery according to embodiment 1, wherein the constraining applies an average compressive force of at least 0.7kPa to each of the first and second projected areas, averaged over the surface area of the first and second projected areas, respectively.

Example 3:

the secondary battery according to embodiment 1, wherein the constraining applies an average compressive force of at least 1.75kPa to each of the first and second projected areas, averaged over the surface area of the first and second projected areas, respectively.

Example 4:

the secondary battery according to embodiment 1, wherein the constraining applies an average compressive force of at least 2.8kPa to each of the first and second projected areas, averaged over the surface area of the first and second projected areas, respectively.

Example 5:

the secondary battery according to embodiment 1, wherein the constraining applies an average compressive force of at least 3.5kPa to each of the first and second projected areas, averaged over the surface area of the first and second projected areas, respectively.

Example 6:

the secondary battery according to embodiment 1, wherein the constraining applies an average compressive force of at least 5.25kPa to each of the first and second projected areas, averaged over the surface area of the first and second projected areas, respectively.

Example 7:

the secondary battery according to embodiment 1, wherein the constraining applies an average compressive force of at least 7kPa to each of the first and second projected areas, averaged over the surface area of the first and second projected areas, respectively.

Example 8:

the secondary battery according to embodiment 1, wherein the constraining applies an average compressive force to each of the first and second projected areas of at least 8.75kPa, averaged over the surface area of the first and second projected areas, respectively.

Example 9:

the secondary battery according to embodiment 1, wherein the constraining applies an average compressive force of at least 10kPa to each of the first and second projected areas, averaged over the surface area of the first and second projected areas, respectively.

Example 10:

the secondary battery according to any one of the preceding embodiments, wherein the surface areas of the first and second longitudinal end surfaces are less than 25% of the surface area of the electrode assembly.

Example 11:

the secondary battery according to any one of the preceding embodiments, wherein the surface area of the first and second longitudinal end surfaces is less than 20% of the surface area of the electrode assembly.

Example 12:

the secondary battery according to any one of the preceding embodiments, wherein the surface area of the first and second longitudinal end surfaces is less than 15% of the surface area of the electrode assembly.

Example 13:

the secondary battery according to any one of the preceding embodiments, wherein the surface areas of the first and second longitudinal end surfaces are less than 10% of the surface area of the electrode assembly.

Example 14:

the secondary battery according to any one of the preceding embodiments, wherein the restraint and housing have a combined volume that is less than 60% of the volume enclosed by the battery housing.

Example 15:

the secondary battery according to any one of the preceding embodiments, wherein the restraint and housing have a combined volume that is less than 45% of the volume enclosed by the battery housing.

Example 16:

the secondary battery according to any one of the preceding embodiments, wherein the restraint and the housing have a combined volume that is less than 30% of the volume enclosed by the battery housing.

Example 17:

the secondary battery according to any one of the preceding embodiments, wherein the restraint and the housing have a combined volume that is less than 20% of the volume enclosed by the battery housing.

Example 18:

the secondary battery according to any one of the preceding embodiments, wherein each member of the electrode group has a bottom, a top, a length L_EWidth W_EHeight H_EAnd a central longitudinal axis A extending from the bottom to the top of each such member and in a direction generally transverse to the stacking direction_ELength L of each member of the electrode group_EAt its central longitudinal axis A_EMeasured in the direction of (a), the width W of each member of the electrode group_EMeasured in the stacking direction, and the height H of each member of the electrode group_EAt right angles to the central longitudinal axis A of each such member_EAnd measured in a direction perpendicular to the stacking direction, L_EW with each member of the electrode group_EAnd H_EAt a ratio of at least 5:1, respectively, of H for each member of the electrode set_EAnd W_EAre between 0.4:1 and 1000:1, respectively.

Example 19:

the secondary battery according to any one of the preceding embodiments, wherein the microporous separator material comprises a particulate material and a binder, has a porosity of at least 20 vol%, and is infiltrated with the non-aqueous liquid electrolyte.

Example 20:

the secondary battery according to any one of the preceding embodiments, wherein the tensioning member is sufficiently close to the side surface to inhibit buckling of the electrode assembly when the secondary battery is cycled between the charged state and the discharged state.

Example 21:

the secondary battery according to any one of the preceding embodiments, wherein a distance between the straining member and the side surface is less than 50% of a minimum Ferrett diameter of the electrode assembly, wherein the Ferrett diameter is measured in the same direction as a distance between the straining member and a side surface of the electrode assembly.

Example 22:

the secondary battery according to any one of the preceding embodiments, wherein a distance between the straining member and the side surface is less than 40% of a minimum Ferrett diameter of the electrode assembly, wherein the Ferrett diameter is measured in the same direction as a distance between the straining member and a side surface of the electrode assembly.

Example 23:

the secondary battery according to any one of the preceding embodiments, wherein a distance between the straining member and the side surface is less than 30% of a minimum Ferrett diameter of the electrode assembly, wherein the Ferrett diameter is measured in the same direction as a distance between the straining member and a side surface of the electrode assembly.

Example 24:

the secondary battery according to any one of the preceding embodiments, wherein a distance between the straining member and the side surface is less than 20% of a minimum Ferrett diameter of the electrode assembly, wherein the Ferrett diameter is measured in the same direction as a distance between the straining member and a side surface of the electrode assembly.

Example 25:

the secondary battery according to any one of the preceding embodiments, wherein a distance between the straining member and the side surface is less than 10% of a minimum Ferrett diameter of the electrode assembly, wherein the Ferrett diameter is measured in the same direction as a distance between the straining member and a side surface of the electrode assembly.

Example 26:

the secondary battery according to any one of the preceding embodiments, wherein a distance between the straining member and the side surface is less than 5% of a minimum Ferrett diameter of the electrode assembly, wherein the Ferrett diameter is measured in the same direction as a distance between the straining member and a side surface of the electrode assembly.

Example 27:

the secondary battery according to any one of the preceding embodiments, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 100 psi.

Example 28:

the secondary battery according to any one of the preceding embodiments, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 200 psi.

Example 29:

the secondary battery according to any one of the preceding embodiments, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 300 psi.

Example 30:

the secondary battery according to any one of the preceding embodiments, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 400 psi.

Example 31:

the secondary battery according to any one of the preceding embodiments, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 500 psi.

Example 32:

the secondary battery according to any one of the preceding embodiments, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 600 psi.

Example 33:

the secondary battery according to any one of the preceding embodiments, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 700 psi.

Example 34:

the secondary battery according to any one of the preceding embodiments, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 800 psi.

Example 35:

the secondary battery according to any one of the preceding embodiments, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 900 psi.

Example 36:

the secondary battery according to any one of the preceding embodiments, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 1000 psi.

Example 37:

the secondary battery according to any one of the preceding embodiments, wherein the secondary battery has a rated capacity, and the first and second longitudinal end surfaces bear such a compressive load when the secondary battery is charged to at least 80% of its rated capacity.

Example 38:

the secondary battery of any preceding embodiment, wherein the electrode structure comprises an anode active electroactive material and the counter electrode structure comprises a cathode active electroactive material.

Example 39:

the secondary battery according to any one of the preceding embodiments, wherein the electrode structure comprises an anode active electroactive material comprising silicon and the counter electrode structure comprises a cathode active electroactive material.

Example 40:

the secondary battery according to any one of the preceding embodiments, wherein the secondary battery includes a set of electrode assemblies, the set including at least two electrode assemblies.

Example 41:

the secondary battery according to any one of embodiments 1-39, wherein the secondary battery includes a set of at least two electrode assemblies, and the constraint maintains pressure on the electrode assemblies within the set as the secondary battery cycles between a charged state and a discharged state.

Example 42:

the secondary battery according to any one of embodiments 1-39, wherein the secondary battery comprises a set of at least two electrode assemblies, and the secondary battery comprises a corresponding number of constraints, wherein, and as the secondary battery cycles between a charged state and a discharged state, each of the constraints maintains pressure on one of the electrode assemblies within the set.

Example 43:

the secondary battery according to any one of the preceding embodiments, wherein the electrode assembly includes at least 5 electrode structures and at least 5 counter electrode structures.

Example 44:

the secondary battery according to any one of the preceding embodiments, wherein the electrode assembly includes at least 10 electrode structures and at least 10 counter electrode structures.

Example 45:

the secondary battery according to any one of the preceding embodiments, wherein the electrode assembly includes at least 50 electrode structures and at least 50 counter electrode structures.

Example 46:

the secondary battery according to any one of the preceding embodiments, wherein the electrode assembly includes at least 100 electrode structures and at least 100 counter electrode structures.

Example 47:

the secondary battery according to any one of the preceding embodiments, wherein the electrode assembly includes at least 500 electrode structures and at least 500 counter electrode structures.

Example 48:

the secondary battery of any preceding embodiment, wherein the restraint comprises a material having an ultimate tensile strength of at least 10000psi (>70 MPa).

Example 49:

the secondary battery according to any one of the preceding embodiments, wherein the constraint comprises a material compatible with a battery electrolyte.

Example 50:

the secondary battery according to any one of the preceding embodiments, wherein the constraint comprises a material that does not significantly corrode at the floating or anode potential of the battery.

Example 51:

the secondary battery according to any one of the preceding embodiments, wherein the restraint comprises a material that does not significantly react or lose mechanical strength at 45 ℃.

Example 52:

the secondary battery according to any one of the preceding embodiments, wherein the restraint comprises a metal, a metal alloy, a ceramic, a glass, a plastic, or a combination thereof.

Example 53:

the secondary battery of any of the preceding embodiments, wherein the constraint comprises a sheet of material having a thickness in a range of about 10 microns to about 100 microns.

Example 54:

the secondary battery of any of the preceding embodiments, wherein the constraint comprises a sheet of material having a thickness in a range of about 30 microns to about 75 microns.

Example 55:

the secondary battery according to any one of the preceding embodiments, wherein the constraint comprises > 50% packing density of carbon fibers.

Example 56:

the secondary battery according to any one of the preceding embodiments, wherein the compression member exerts a pressure on the first and second longitudinal end surfaces that exceeds a pressure maintained on the electrode assembly in each of two directions that are perpendicular to each other and to the stacking direction by at least 3 times.

Example 57:

the secondary battery according to any one of the preceding embodiments, wherein the compression member exerts a pressure on the first and second longitudinal end surfaces that exceeds a pressure maintained on the electrode assembly in each of two directions that are perpendicular to each other and to the stacking direction by at least 3 times.

Example 58:

the secondary battery according to any one of the preceding embodiments, wherein the compression member exerts a pressure on the first and second longitudinal end surfaces that exceeds a pressure maintained on the electrode assembly in each of two directions that are perpendicular to each other and to the stacking direction by at least 4 times.

Example 59:

according to the secondary battery of any one of the preceding embodiments, the compression member exerts a pressure on the first and second longitudinal end surfaces that exceeds a pressure maintained on the electrode assembly in each of two directions perpendicular to each other and to the stacking direction by at least 5 times.

Example 60:

an energy storage device for cycling between a charged state and a discharged state, the energy storage device comprising a housing, an electrode assembly and a non-aqueous liquid electrolyte within the housing, and a constraint which maintains a pressure on the electrode assembly as the energy storage device cycles between the charged state and the discharged state, the electrode assembly comprising a set of electrode structures, a set of counter electrode structures and an electrically insulating microporous separator material between the electrodes and members of the counter electrode assembly, wherein the electrode structure comprises a porous membrane material and the electrode assembly comprises a porous membrane material which is arranged to be porous to allow the electrolyte to flow between the electrode structure and the counter electrode structure

The electrode assembly has opposing first and second longitudinal end surfaces spaced apart along the longitudinal axis, and a side surface surrounding the longitudinal axis and connecting the first and second longitudinal end surfaces, a combined surface area of the first and second longitudinal end surfaces being less than 33% of a combined surface area of the side surface and the first and second longitudinal end surfaces,

the members of the electrode group and the members of the counter electrode group are arranged in an alternating order in a stacking direction parallel to the longitudinal axis within the electrode assembly,

the constraining comprises first and second compression members connected by at least one tensioning member pulling the compression members toward each other, and

the pressure maintained on the electrode assembly in the stacking direction is restrained, which exceeds the pressure maintained on the electrode assembly in each of two directions perpendicular to each other and to the stacking direction.

Example 61:

the energy storage device of embodiment 60, wherein the energy storage device is a secondary battery.

Example 62:

the energy storage device of embodiment 60, wherein the constraint comprises first and second compression members overlying longitudinal end surfaces of the electrode assembly.

Example 63:

the energy storage device of any preceding embodiment, wherein the constraint comprises at least one compression member inside the longitudinal end surface.

Example 64:

the energy storage device according to any of the preceding embodiments, wherein a projection of the members of the electrode group and the counter electrode group on the first longitudinal surface encompasses a first projection area and a projection of the members of the electrode group and the counter electrode group on the second longitudinal surface encompasses a second projection area, and wherein the first and second projection areas each comprise at least 50% of a surface area of the first and second longitudinal end surfaces, respectively.

Example 65:

the energy storage apparatus according to any of the preceding embodiments, wherein a projection of the electrode group and a member of the counter electrode group on the first longitudinal surface encompasses a first projection area and a projection of the electrode group and a member of the counter electrode group on the second longitudinal surface encompasses a second projection area, and wherein an average compressive force of at least 0.7kPa is constrained to be applied to each of the first and second projection areas, averaged over the surface area of the first and second projection areas, respectively.

Example 66:

the energy storage device of any preceding embodiment, wherein the constraining applies an average compressive force to each of the first and second projected areas of at least 1.75kPa, averaged over the surface area of the first and second projected areas, respectively.

Example 67:

the energy storage device of any preceding embodiment, wherein the constraining applies an average compressive force to each of the first and second projected areas of at least 2.8kPa, averaged over the surface area of the first and second projected areas, respectively.

Example 68:

the energy storage device of any preceding embodiment, wherein the constraining applies an average compressive force to each of the first and second projected areas of at least 3.5kPa, averaged over the surface area of the first and second projected areas, respectively.

Example 69:

the energy storage device of any preceding embodiment, wherein the constraining applies an average compressive force to each of the first and second projected areas of at least 5.25kPa, averaged over the surface area of the first and second projected areas, respectively.

Example 70:

the energy storage device of any preceding embodiment, wherein the constraining applies an average compressive force to each of the first and second projected areas of at least 7kPa, averaged over the surface area of the first and second projected areas, respectively.

Example 71:

the energy storage device of any preceding embodiment, wherein the constraining applies an average compressive force to each of the first and second projected areas of at least 8.75kPa, averaged over the surface area of the first and second projected areas, respectively.

Example 72:

the energy storage device of any preceding embodiment, wherein the constraining applies an average compressive force to each of the first and second projected areas of at least 10kPa, averaged over the surface area of the first and second projected areas, respectively.

Example 73:

the energy storage device of any preceding embodiment, wherein a combined surface area of the first and second longitudinal end surfaces is less than 25% of a surface area of the electrode assembly.

Example 74:

the energy storage device of any preceding embodiment, wherein a combined surface area of the first and second longitudinal end surfaces is less than 20% of a surface area of the electrode assembly.

Example 75:

the energy storage device of any preceding embodiment, wherein a combined surface area of the first and second longitudinal end surfaces is less than 15% of a surface area of the electrode assembly.

Example 76:

the energy storage device of any preceding embodiment, wherein a combined surface area of the first and second longitudinal end surfaces is less than 10% of a surface area of the electrode assembly.

Example 77:

the energy storage device of any preceding embodiment, wherein the constraint and the enclosure have a combined volume that is less than 60% of a volume enclosed by the enclosure.

Example 78:

the energy storage device of any preceding embodiment, wherein the constraint and the enclosure have a combined volume that is less than 45% of a volume enclosed by the enclosure.

Example 79:

the energy storage device of any preceding embodiment, wherein the constraint and the enclosure have a combined volume that is less than 30% of a volume enclosed by the enclosure.

Example 80:

the energy storage device of any preceding embodiment, wherein the constraint and the enclosure have a combined volume that is less than 20% of a volume enclosed by the enclosure.

Example 81:

the energy storage device of any preceding embodiment, wherein each member of the electrode set has a bottom, a top, a length L_EWidth W_EHeight H_EAnd a central longitudinal axis A extending from the bottom to the top of each such member and in a direction generally transverse to the stacking direction_ELength L of each member of the electrode group_EAt its central longitudinal axis A_EMeasured in the direction of (a), the width W of each member of the electrode group_EMeasured in the stacking direction, and the height H of each member of the electrode group_EAt right angles to the central longitudinal axis A of each such member_EAnd measured in a direction perpendicular to the stacking direction, L_EW with each member of the electrode group_EAnd H_EAt a ratio of at least 5:1, respectively, of H for each member of the electrode set_EAnd W_EAre between 0.4:1 and 1000:1, respectively.

Example 82:

the energy storage device of any preceding embodiment, wherein the microporous separator material comprises a particulate material and a binder, has a porosity of at least 20 vol%, and is infiltrated with the non-aqueous liquid electrolyte.

Example 83:

the energy storage device of any of the preceding embodiments, wherein the tensioning member is sufficiently close to the side surface to inhibit buckling of the electrode assembly when the energy storage device is cycled between the charged state and the discharged state.

Example 84:

the energy storage device of any preceding embodiment, wherein the distance between the tensioning member and the side is less than 50% of the minimum Ferrett diameter of the electrode assembly.

Example 85:

the energy storage device of any preceding embodiment, wherein the distance between the tensioning member and the side is less than 40% of the minimum Ferrett diameter of the electrode assembly.

Example 86:

the energy storage device of any preceding embodiment, wherein the distance between the tensioning member and the side is less than 30% of the minimum Ferrett diameter of the electrode assembly.

Example 87:

the energy storage device of any preceding embodiment, wherein the distance between the tensioning member and the side is less than 20% of the minimum Ferrett diameter of the electrode assembly.

Example 88:

the energy storage device of any preceding embodiment, wherein the distance between the tensioning member and the side is less than 10% of the minimum Ferrett diameter of the electrode assembly.

Example 89:

the energy storage device of any preceding embodiment, wherein the distance between the tensioning member and the side is less than 5% of the minimum Ferrett diameter of the electrode assembly.

Example 90:

the energy storage device of any preceding embodiment, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 100 psi.

Example 91:

the energy storage device of any preceding embodiment, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 200 psi.

Example 92:

the energy storage device of any preceding embodiment, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 300 psi.

Example 93:

the energy storage device of any preceding embodiment, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 400 psi.

Example 94:

the energy storage device of any preceding embodiment, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 500 psi.

Example 95:

the energy storage device of any preceding embodiment, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 600 psi.

Example 96:

the energy storage device of any preceding embodiment, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 700 psi.

Example 97:

the energy storage device of any preceding embodiment, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 800 psi.

Example 98:

the energy storage device of any preceding embodiment, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 900 psi.

Example 99:

the energy storage device of any preceding embodiment, wherein each of the first and second longitudinal end surfaces is subjected to a compressive load of at least 1000 psi.

Example 100:

the energy storage device of any preceding embodiment, wherein the energy storage device has a rated capacity, and the first and second longitudinal end surfaces bear such compressive loads when the energy storage device is charged to at least 80% of its rated capacity.

Example 101:

the energy storage device of any preceding embodiment, wherein the electrode structure comprises an anodically active electroactive material and the counter electrode structure comprises a cathodically active electroactive material.

Example 102:

the energy storage device of any preceding embodiment, wherein the electrode structure comprises an anode active electroactive material comprising silicon and the counter electrode structure comprises a cathode active electroactive material.

Example 103:

the energy storage device according to any of the preceding embodiments, wherein the energy storage device comprises a set of electrode assemblies, the set comprising at least two electrode assemblies.

Example 104:

the energy storage device of any of embodiments 60-103, wherein the energy storage device comprises a set of at least two electrode assemblies, and the constraining maintains pressure on the electrode assemblies within the set as the energy storage device cycles between a charged state and a discharged state.

Example 105:

the energy storage device of any of embodiments 1-60-103, wherein the energy storage device comprises a set of at least two electrode assemblies and the energy storage device comprises a corresponding number of constraints, wherein and as the energy storage device cycles between a charged state and a discharged state, each of the constraints maintains a pressure on one of the electrode assemblies within the set.

Example 106:

the energy storage device of any preceding embodiment, wherein the electrode assembly comprises at least 5 electrode structures and at least 5 counter electrode structures.

Example 107:

the energy storage device of any preceding embodiment, wherein the electrode assembly comprises at least 10 electrode structures and at least 10 counter electrode structures.

Example 108:

the energy storage device of any preceding embodiment, wherein the electrode assembly comprises at least 50 electrode structures and at least 50 counter electrode structures.

Example 109:

the energy storage device of any preceding embodiment, wherein the electrode assembly comprises at least 100 electrode structures and at least 100 counter electrode structures.

Example 110:

the energy storage device of any preceding embodiment, wherein the electrode assembly comprises at least 500 electrode structures and at least 500 counter electrode structures.

Example 111:

the energy storage device of any preceding embodiment, wherein the constraint comprises a material having an ultimate tensile strength of at least 10000psi (>70 MPa).

Example 112:

the energy storage device of any preceding embodiment, wherein the constraint comprises a material compatible with the electrolyte.

Example 113:

the energy storage device of any of the preceding embodiments, wherein the constraint comprises a material that does not significantly corrode at the floating or anodic potential of the energy storage device.

Example 114:

the energy storage device of any preceding embodiment, wherein the constraint comprises a material that does not significantly react or lose mechanical strength at 45 ℃.

Example 115:

the energy storage device of any preceding embodiment, wherein the constraint comprises a metal, a metal alloy, a ceramic, a glass, a plastic, or a combination thereof.

Example 116:

the energy storage device of any preceding embodiment, wherein the constraint comprises a sheet of material having a thickness in a range of about 10 microns to about 100 microns.

Example 117:

the energy storage device of any preceding embodiment, wherein the constraint comprises a sheet of material having a thickness in a range of about 30 microns to about 75 microns.

Example 118:

the energy storage device of any preceding embodiment, wherein the constraint comprises > 50% packing density of carbon fibers.

Example 119:

the energy storage device according to any one of the preceding embodiments, wherein the compression member exerts a pressure on the first and second longitudinal end surfaces that exceeds a pressure maintained on the electrode assembly in each of two directions that are perpendicular to each other and to the stacking direction by at least a factor of 3.

Example 120:

the energy storage device according to any one of the preceding embodiments, wherein the compression member exerts a pressure on the first and second longitudinal end surfaces that exceeds a pressure maintained on the electrode assembly in each of two directions that are perpendicular to each other and to the stacking direction by at least a factor of 3.

Example 121:

the energy storage device according to any one of the preceding embodiments, wherein the compression member exerts a pressure on the first and second longitudinal end surfaces that exceeds a pressure maintained on the electrode assembly in each of two directions that are perpendicular to each other and to the stacking direction by at least a factor of 4.

Example 122:

the energy storage device according to any one of the preceding embodiments, the compression member exerts a pressure on the first and second longitudinal end surfaces that exceeds a pressure maintained on the electrode assembly in each of two directions that are perpendicular to each other and to the stacking direction by at least a factor of 5.

As various changes could be made in the above articles, combinations, and methods without departing from the scope of the disclosure, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

All directional descriptors such as top, bottom, left, right, etc. are for ease of reference with respect to the drawings only and are not meant to be limiting.

Claims (10)

1. An energy storage device for cycling between a charged state and a discharged state, the energy storage device comprising a housing, an electrode assembly and a non-aqueous liquid electrolyte within the housing, and a constraint that maintains pressure on the electrode assembly as the energy storage device cycles between the charged state and the discharged state, the electrode assembly comprising a set of electrode structures, a set of counter electrode structures, and an electrically insulating microporous separator material between an electrode and a member of a counter electrode set, wherein the electrode structure comprises a first electrode and a second electrode, and the first electrode is a porous separator material that is electrically insulating, and the second electrode is electrically insulating microporous separator material, and the second electrode is electrically insulating, and the second electrode structure is electrically insulating, and the second electrode is electrically insulating, and the second electrode is a cell is electrically insulating, and a cell, and a cell

The electrode assembly having opposing first and second longitudinal end surfaces separated along a longitudinal axis and a side surface surrounding the longitudinal axis and connecting the first and second longitudinal end surfaces, the combined surface area of the first and second longitudinal end surfaces being less than 33% of the combined surface area of the side surface and the first and second longitudinal end surfaces,

the members of the electrode group and the members of the counter electrode group are arranged in an alternating order in a stacking direction parallel to the longitudinal axis within the electrode assembly,

the constraint comprises a first compression member and a second compression member connected by at least one tensioning member pulling the compression members towards each other, and

the restraining maintains a pressure on the electrode assembly in the stacking direction that exceeds a pressure maintained on the electrode assembly in each of two directions that are perpendicular to each other and to the stacking direction.

2. The energy storage device of claim 1, wherein the energy storage device is a secondary battery.

3. The energy storage device of claim 1, wherein the constraint comprises a first compression member and a second compression member overlying a longitudinal end surface of the electrode assembly.

4. The energy storage device of any of the preceding claims, wherein the constraint comprises at least one compression member inside the longitudinal end surface.

5. The energy storage device of any preceding claim, wherein a projection of the members of the electrode and counter electrode groups on the first longitudinal surface encompasses a first projection area and a projection of the members of the electrode and counter electrode groups on the second longitudinal surface encompasses a second projection area, and wherein the first and second projection areas each comprise at least 50% of a surface area of the first and second longitudinal end surfaces, respectively.

6. The energy storage device of any preceding claim, wherein a projection of the members of the electrode and counter electrode groups on the first longitudinal surface encompasses a first projection area and a projection of the members of the electrode and counter electrode groups on the second longitudinal surface encompasses a second projection area, and wherein the constraint applies an average compressive force of at least 0.7kPa to each of the first and second projection areas, averaged over the surface areas of the first and second projection areas, respectively.

7. The energy storage device of any preceding claim, wherein the constraint applies an average compressive force to each of the first and second projected areas of at least 1.75kPa, averaged over the surface area of the first and second projected areas, respectively.

8. The energy storage device of any preceding claim, wherein the constraint applies an average compressive force to each of the first and second projected areas of at least 2.8kPa, averaged over the surface area of the first and second projected areas, respectively.

9. The energy storage device of any preceding claim, wherein the constraint applies an average compressive force to each of the first and second projected areas of at least 3.5kPa, averaged over the surface area of the first and second projected areas, respectively.

10. The energy storage device of any preceding claim, wherein the constraint applies an average compressive force to each of the first and second projected areas of at least 5.25kPa, averaged over the surface area of the first and second projected areas, respectively.