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WO2018123520A1 - Dispositif de stockage d'énergie électrique - Google Patents

Dispositif de stockage d'énergie électrique Download PDF

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Publication number
WO2018123520A1
WO2018123520A1 PCT/JP2017/044230 JP2017044230W WO2018123520A1 WO 2018123520 A1 WO2018123520 A1 WO 2018123520A1 JP 2017044230 W JP2017044230 W JP 2017044230W WO 2018123520 A1 WO2018123520 A1 WO 2018123520A1
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WO
WIPO (PCT)
Prior art keywords
separator
power storage
storage device
storage module
compression rate
Prior art date
Application number
PCT/JP2017/044230
Other languages
English (en)
Japanese (ja)
Inventor
毅 真里谷
耕二郎 田丸
寿光 田中
Original Assignee
株式会社豊田自動織機
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社豊田自動織機 filed Critical 株式会社豊田自動織機
Publication of WO2018123520A1 publication Critical patent/WO2018123520A1/fr

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/10—Multiple hybrid or EDL capacitors, e.g. arrays or modules
    • H01G11/12—Stacked hybrid or EDL capacitors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/52—Separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G2/00—Details of capacitors not covered by a single one of groups H01G4/00-H01G11/00
    • H01G2/02—Mountings
    • H01G2/04—Mountings specially adapted for mounting on a chassis
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/24—Alkaline accumulators
    • H01M10/30—Nickel accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H01M50/491—Porosity
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present disclosure relates to a power storage device.
  • a bipolar battery including a bipolar electrode in which a positive electrode is formed on one surface of a current collector plate and a negative electrode is formed on the other surface is known (see Patent Document 1).
  • a bipolar battery a plurality of bipolar electrodes are stacked in series across a separator holding an electrolyte layer.
  • a separator a microporous membrane separator or a nonwoven fabric separator is used.
  • the battery is pressed from above and below using an iron plate and bolts and nuts.
  • a restraining force is applied to the bipolar electrode by restraining plates provided at both ends in the stacking direction and restraining members such as bolts and nuts.
  • the restraint plate is designed so that fatigue failure does not occur due to the internal pressure fluctuation (load fluctuation) of the cell.
  • a deformable member such as a resin is not provided between the constraining plate and the bipolar electrode, so that the influence of fluctuations in the internal pressure of the cell is large.
  • Bipolar electrodes also tend to have a large area, and from this point of view, the influence of cell internal pressure fluctuations is large. Therefore, when using a restraint plate having a predetermined strength (thickness), it is necessary to carefully examine the pressure applied to the restraint plate.
  • This disclosure is intended to provide a power storage device that can suppress load fluctuations with respect to a restraining member such as a restraining plate for restraining stacked bipolar electrodes.
  • a power storage device includes a plurality of bipolar electrodes each including an electrode plate, a positive electrode provided on a first surface of the electrode plate, and a negative electrode provided on a second surface of the electrode plate, and a plurality of bipolar electrodes And at least one power storage module in which a plurality of bipolar electrodes are stacked in the stacking direction via the separator, and both ends of the at least one power storage module in the stacking direction.
  • a restraint structure that includes a first restraining member and a second restraining member provided in a portion, and applies a compressive force in a stacking direction to a portion provided with a positive electrode, a separator, and a negative electrode in at least one power storage module;
  • the separator is made of a porous resin, and the compressibility of the separator compressed by the constraining structure is greater than 0% and less than 40%.
  • the power storage module is formed by stacking a plurality of bipolar electrodes in the stacking direction via separators.
  • the restraint structure including the first restraining member and the second restraining member, a compressive force is applied to the portion where the positive electrode, the separator, and the negative electrode are provided.
  • the compression ratio of the separator is greater than 0% and less than 40%, deformation of the restraint member due to fluctuations in the internal pressure of the cell and relaxation of the separator compression amount (that is, crushing amount) occur simultaneously.
  • This compression rate range is a range suitable for a separator made of a porous resin.
  • the load fluctuation on the restraining member is suitably suppressed. This leads to a reduction in the stress amplitude of the restraining member.
  • the separator is not compressed (when it is not crushed, that is, when the compression rate is 0%), the stress amplitude tends to increase. Therefore, the said structure is advantageous from a viewpoint of the fatigue
  • the compression rate of the separator compressed by the restraint structure may be 10% or more.
  • the amount of compression of the separator that is, the amount of crushing
  • the separator may be separated from the bipolar electrode.
  • the distance between the bipolar electrodes cannot be controlled, and the ion conduction distance may become extremely long. These phenomena are not preferable because they increase the resistance in the power storage module. Therefore, if the compression ratio of the separator is 10% or more, the separation phenomenon of the separator from the bipolar electrode can be prevented, and an increase in resistance can be prevented. As a result, a desired output can be maintained.
  • the compression rate of the separator compressed by the constraining structure may be 30% or less. If the compression rate of the separator is increased too much, the surface pressure that the restraining member receives from the separator becomes high, so that it is necessary to increase the strength of the restraining member, that is, the plate thickness.
  • a plate thickness in an appropriate range can be set with respect to the assumed internal pressure of the cell.
  • the plate thickness in the proper range is a plate that does not deform the constraining member against the assumed internal pressure (it does not deform as far as the separator is separated) and that satisfies the desired thickness in terms of downsizing the power storage device. It is thick.
  • the compression ratio of the separator compressed by the constraining structure may be 20% or more and 30% or less.
  • the lower limit value and the upper limit value are set in this way, the possibility of various problems such as separation of the separator, enlargement of the restraint member due to increased surface pressure by the separator, and electrolyte diffusion failure is more reliably reduced. it can.
  • the porous resin may be made of non-woven fabric.
  • the storage module may be a nickel metal hydride secondary battery.
  • the above compression rate range is particularly suitable.
  • the management of the compression rate of the separator has a great effect in terms of the reliability and miniaturization of the nickel-hydrogen secondary battery.
  • the compression rate of the separator and the thicknesses of the first restraining member and the second restraining member may be set. Thereby, the separation of the separator from the bipolar electrode during normal operation can be suppressed. Moreover, it can suppress that a 1st restraint member and a 2nd restraint member yield by the reaction force from the compressed separator.
  • the compression ratio of the separator may be set so that the thickness of the first restraining member and the second restraining member is minimized under the above range. In this case, the physique of the power storage device with respect to the output can be reduced. Therefore, the power storage device can be highly integrated.
  • the separator compression rate and the thickness of the first and second restraining members may be set so that the initial minimum porosity of the separator is 33% or more.
  • the electrolyte solution can be diffused without any problem, and a desired output can be maintained. Further, it is possible to cause sufficient gas escape during gas generation.
  • the compression rate of the separator and the thickness of the first restraining member and the second restraining member are such that the stress generated in the restraining structure during the normal operation of the power storage module is less than the fatigue strength of the first restraining member and the second restraining member. It may be set. In this case, it is possible to prevent the first restraining member and the second restraining member from being fatigued and destroyed by the reaction force from the compressed separator.
  • FIG. 3A is a sectional view showing the bipolar electrode and the separator before compression
  • FIG. 3B is a sectional view showing the bipolar electrode and the separator after compression.
  • FIG. 3A is a sectional view showing the bipolar electrode and the separator before compression
  • FIG. 3B is a sectional view showing the bipolar electrode and the separator after compression.
  • the power storage device 10 shown in FIG. 1 is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles.
  • the power storage device 10 includes a plurality (three in the present embodiment) of power storage modules 12, but may include a single power storage module 12.
  • the power storage module 12 is a bipolar battery.
  • the power storage module 12 is a secondary battery such as a nickel hydride secondary battery or a lithium ion secondary battery, but may be an electric double layer capacitor. In the following description, a nickel metal hydride secondary battery is illustrated.
  • the plurality of power storage modules 12 can be stacked via a conductive plate 14 such as a metal plate, for example.
  • a conductive plate 14 such as a metal plate, for example.
  • the conductive plates 14 are also arranged outside the power storage modules 12 positioned at both ends in the stacking direction (Z direction) of the power storage modules 12.
  • the conductive plate 14 is electrically connected to the adjacent power storage module 12. Thereby, the some electrical storage module 12 is connected in series in the lamination direction.
  • a positive electrode terminal 24 is connected to the conductive plate 14 located at one end
  • a negative electrode terminal 26 is connected to the conductive plate 14 located at the other end.
  • the positive terminal 24 may be integrated with the conductive plate 14 to be connected.
  • the negative electrode terminal 26 may be integrated with the conductive plate 14 to be connected.
  • the positive electrode terminal 24 and the negative electrode terminal 26 extend in a direction (X direction) intersecting the stacking direction.
  • the positive and negative terminals 24 and 26 can charge and discharge the power storage device 10.
  • the conductive plate 14 can also function as a heat radiating plate for releasing heat generated in the power storage module 12.
  • a refrigerant such as air passes through the plurality of gaps 14a provided inside the conductive plate 14, heat from the power storage module 12 can be efficiently released to the outside.
  • Each gap 14a extends, for example, in a direction (Y direction) intersecting the stacking direction.
  • the conductive plate 14 is smaller than the power storage module 12, but may be the same as or larger than the power storage module 12.
  • the power storage device 10 may include a restraining structure 16 that restrains the alternately stacked power storage modules 12 and conductive plates 14 in the stacking direction.
  • the restraint structure 16 connects, for example, a pair of restraint plates 16A and 16B (first restraint member and second restraint member) provided at both ends in the stacking direction of the plurality of power storage modules 12 and the restraint plates 16A and 16B. Connecting members (such as bolts 18 and nuts 20).
  • Constraint plates 16A and 16B are made of metal such as iron, for example. More specifically, the material constituting the restraining plates 16A and 16B is, for example, carbon steel such as S45C (JIS standard), aluminum die casting (aluminum alloy die casting) such as ADC10, or the like.
  • the restraint plates 16A and 16B have a predetermined plate thickness.
  • the plate thickness of the restraining plates 16A and 16B can be determined based on several criteria. For example, the plate thickness of the restraining plates 16A and 16B is determined so as to be deformed so as not to cause separation of the separator 40 described later with respect to the internal pressure assumed in the cell.
  • the plate thickness is designed so that the deformation of the constraining plates 16A and 16B is less than the design standard (criteria) up to an internal pressure of 4 MPa. Is done. As long as these criteria are satisfied, the restraining plates 16A and 16B should be as thin as possible.
  • An insulating film 22 such as a resin film is disposed between the constraining plates 16A and 16B and the conductive plate 14.
  • each of the restraining plates 16A and 16B and the insulating film 22 has, for example, a rectangular shape.
  • the insulating film 22 is larger than the conductive plate 14, and the restraining plates 16 ⁇ / b> A and 16 ⁇ / b> B are larger than the power storage module 12.
  • an insertion hole 16A1 through which the shaft portion of the bolt 18 is inserted is provided at a position on the outer side of the power storage module 12 at the edge of the restraint plate 16A.
  • an insertion hole 16 ⁇ / b> B ⁇ b> 1 through which the shaft portion of the bolt 18 is inserted is provided at a position on the outer side of the power storage module 12 at the edge of the restraining plate 16 ⁇ / b> B when viewed from the stacking direction.
  • the insertion hole 16A1 and the insertion hole 16B1 are located at the corners of the restraint plates 16A, 16B.
  • One constraining plate 16A is abutted against the conductive plate 14 connected to the negative electrode terminal 26 via the insulating film 22, and the other constraining plate 16B has the insulating film 22 applied to the conductive plate 14 connected to the positive electrode terminal 24.
  • the bolt 18 is passed through the insertion hole 16A1 and the insertion hole 16B1, for example, from one restraint plate 16A side toward the other restraint plate 16B side.
  • a nut 20 is screwed onto the tip of the bolt 18 protruding from the other restraining plate 16B.
  • the insulating film 22, the conductive plate 14, and the power storage module 12 are sandwiched and unitized, and a restraining load (compression force) is applied in the stacking direction.
  • the power storage module 12 illustrated in FIG. 2 includes a stacked body 30 in which a plurality of bipolar electrodes 32 are stacked. When viewed from the stacking direction of the bipolar electrode 32, the stacked body 30 has, for example, a rectangular shape. A separator 40 may be disposed between the adjacent bipolar electrodes 32.
  • Each bipolar electrode 32 includes an electrode plate 34, a positive electrode 36 provided on the first surface 34 c of the electrode plate 34, and a negative electrode 38 provided on the second surface 34 d of the electrode plate 34.
  • the positive electrode 36 of one bipolar electrode 32 faces the negative electrode 38 of one bipolar electrode 32 adjacent in the stacking direction across the separator 40, and the negative electrode 38 of one bipolar electrode 32 connects the separator 40. It faces the positive electrode 36 of the other bipolar electrode 32 that is adjacent in the stacking direction.
  • the separator 40 is sandwiched between the positive electrode 36 and the negative electrode 38.
  • an electrode plate 34 having a negative electrode 38 disposed on the inner surface (the lower surface in the drawing) is disposed at one end of the stacked body 30.
  • the electrode plate 34 corresponds to a negative terminal electrode.
  • an electrode plate 34 having a positive electrode 36 disposed on the inner surface (the upper surface in the drawing) is disposed at the other end of the stacked body 30.
  • This electrode plate 34 corresponds to a positive terminal electrode.
  • the negative electrode 38 of the negative electrode-side termination electrode faces the positive electrode 36 of the uppermost bipolar electrode 32 with the separator 40 interposed therebetween.
  • the positive electrode 36 of the positive terminal electrode is opposed to the negative electrode 38 of the lowermost bipolar electrode 32 with the separator 40 interposed therebetween.
  • the electrode plates 34 of these termination electrodes are connected to the adjacent conductive plates 14 (see FIG. 1).
  • the power storage module 12 includes a cylindrical resin portion 50 that extends in the stacking direction of the bipolar electrodes 32 and accommodates the stacked body 30.
  • the resin part 50 holds the peripheral edge part 34 a of the plurality of electrode plates 34.
  • the resin part 50 is configured to surround the laminated body 30.
  • the resin part 50 is joined to the peripheral part 34a of the electrode plate 34, and the first seal part 52 that holds the peripheral part 34a and the first seal part 52 in the direction (X direction and Y direction) intersecting the stacking direction. 2nd seal part 54 provided in the outside.
  • the 1st seal part 52 which constitutes the inner wall of resin part 50 is provided over the perimeter of peripheral part 34a of electrode board 34 in a plurality of bipolar electrodes 32 (namely, layered product 30).
  • the first seal portion 52 is welded, for example, to the peripheral portion 34a of the electrode plate 34, and seals the peripheral portion 34a.
  • the peripheral edge 34 a of the electrode plate 34 of each bipolar electrode 32 is held in a state of being buried in the first seal portion 52.
  • the peripheral portions 34 a of the electrode plates 34 disposed at both ends of the stacked body 30 are also held in a state of being buried in the first seal portion 52.
  • an internal space that is airtightly partitioned by the electrode plates 34 and 34 and the first seal portion 52 is formed between the electrode plates 34 and 34 adjacent in the stacking direction.
  • An electrolytic solution (not shown) made of an alkaline solution such as an aqueous potassium hydroxide solution is accommodated in the internal space.
  • the second seal part 54 constituting the outer wall of the resin part 50 covers the outer peripheral surface 52a of the first seal part 52 extending in the stacking direction of the bipolar electrodes 32.
  • the inner peripheral surface 54a of the second seal portion 54 is welded, for example, to the outer peripheral surface 52a of the first seal portion 52, and seals the outer peripheral surface 52a.
  • the welding surface (joint surface) of the second seal portion 54 with respect to the first seal portion 52 forms, for example, four rectangular planes.
  • the resin part 50 (the first seal part 52 and the second seal part 54) is formed in a rectangular cylindrical shape by, for example, injection molding using an insulating resin.
  • the resin material constituting the resin portion 50 include polypropylene (PP), polyphenylene sulfide (PPS), and modified polyphenylene ether (modified PPE).
  • the resin part 50 regulates the movement of gas and electrolyte from one cell to another cell. Thereby, the insulation between adjacent cells is ensured.
  • the electrode plate 34 is a rectangular metal foil made of nickel, for example.
  • the peripheral edge 34a of the electrode plate 34 is an uncoated region where the positive electrode active material and the negative electrode active material are not coated. In the uncoated region, the electrode plate 34 is exposed. The uncoated region is buried and held in the first seal portion 52 constituting the inner wall of the resin portion 50.
  • An example of the positive electrode active material constituting the positive electrode 36 is nickel hydroxide.
  • Examples of the negative electrode active material constituting the negative electrode 38 include a hydrogen storage alloy.
  • the formation region of the negative electrode 38 on the second surface 34 d of the electrode plate 34 may be slightly larger than the formation region of the positive electrode 36 on the first surface 34 c of the electrode plate 34.
  • the separator 40 is formed in a sheet shape, for example.
  • the separator 40 has a rectangular shape, for example.
  • the separator 40 is made of a porous resin.
  • Separator 40 consists of a nonwoven fabric which is a kind of porous resin, for example.
  • the material forming the separator 40 is a porous film made of a polyolefin resin such as polyethylene (PE) or polypropylene (PP), a woven fabric or a non-woven fabric made of polypropylene, polyethylene terephthalate (PET), methylcellulose or the like. Etc. are exemplified.
  • the electrolyte is alkaline, and thus the material forming the separator 40 is required to have alkali resistance.
  • a glass fiber separator cannot be used.
  • the fibers of the nonwoven fabric may be made of polypropylene (PP) and polyethylene (PE). Surface treatment for imparting affinity to the electrolyte solution may be performed on the fibers of the nonwoven fabric.
  • PP polypropylene
  • PE polyethylene
  • Surface treatment for imparting affinity to the electrolyte solution may be performed on the fibers of the nonwoven fabric.
  • the separator 40 may be reinforced with a vinylidene fluoride resin compound.
  • the separator 40 is not limited to a sheet shape, and may be a bag shape.
  • the conductive plate 14 connected to the power storage module 12 is disposed, for example, inside the resin portion 50.
  • the conductive plate 14 abuts on the electrode plates 34 provided at both ends of the stacked body 30 in the stacking direction, and transmits the compressive force from the restraining structure 16 to the stacked body 30.
  • the restraint structure 16 applies a compressive force in the stacking direction to the positive electrode 36, the separator 40, and the negative electrode 38 in each power storage module 12.
  • the separator 40 disposed between the positive electrode 36 and the negative electrode 38 of the bipolar electrode 32 is compressed at a predetermined compression rate.
  • the surface pressure (compression surface pressure and load surface pressure) received by the constraining plates 16A and 16B by the compressed separator 40 is considered. Since the separator 40 is compressed with an appropriate compression rate, the stress amplitude of the restraining plates 16A and 16B is reduced.
  • the compression rate is easy to manage. The compression rate is a ratio indicating how much the thickness in the stacking direction of the separator 40 after compression is reduced (the amount of compression and crushing) with respect to the thickness in the stacking direction of the separator 40 before compression.
  • FIG. 4 is a diagram illustrating the compressive load characteristics of the separator 40.
  • the compression surface pressure is a surface pressure that the constraining plates 16A and 16B receive from the separator 40 only because the separator 40 is compressed without taking the cell internal pressure into consideration.
  • the compression rate compressing amount
  • the compression surface pressure tends to increase rapidly. This means that the higher the compression ratio, the higher the possibility of exceeding the deformation criteria of the restraining plates 16A and 16B. For example, if the compression rate is 40% or more, the compression surface pressure exceeds 6 MPa, which is not preferable.
  • FIG. 5 is a diagram showing the load surface pressure of the restraining plates 16A and 16B with respect to the cell internal pressure.
  • This load surface pressure is the surface pressure that the restraining plates 16A and 16B receive when the cell internal pressure is taken into consideration.
  • FIG. 5 is a simulation result regarding the surface pressure in the nickel-hydrogen secondary battery. In this simulation, the compressive load characteristic of the separator 40 shown in FIG. 4 is considered. As shown in FIG. 5, the higher the initial compression ratio, the smaller the increase width of the restraint plate load surface pressure, that is, the stress amplitude. Further, when the initial compression ratio is 10%, 17%, and 23%, the restraint plate load surface pressure is always higher than the cell internal pressure.
  • FIG. 6 is a diagram illustrating a change in the output of the power storage device 10 when the compression rate of the separator 40 is changed.
  • the change in output is shown as a ratio, with the maximum output being 100%.
  • FIG. 6 shows a case where SOC (State Of Charge) 60%, temperature 25 ° C., output 10 seconds, 1.0 V cut, and initial porosity of separator 40 is 65%.
  • SOC State Of Charge
  • the compression rate exceeds 40%
  • the output is rapidly reduced. It is considered that this is because, when the compressibility of the separator 40 is increased too much, the gaps in the separator 40 are reduced and the diffusion of the electrolytic solution is hindered.
  • “1.0V cut” means that the output is taken out to 1.0V. If the value is less than that, it is judged as overdischarge, and no output is taken out.
  • the compression rate of the separator 40 compressed by the constraining structure 16 is greater than 0% and less than 40%. More preferably, the compression rate of the separator 40 compressed by the constraining structure 16 may be 10% or more. More preferably, the compression rate of the separator 40 compressed by the constraining structure 16 may be 30% or less. More preferably, the compression rate of the separator 40 compressed by the constraining structure 16 may be 20% or more and 30% or less. The compressibility of the separator 40 compressed by the constraining structure 16 may be 25% or less, 20% or less, or 15% or less.
  • the compression surface pressure is about 0.1 MPa.
  • the compression surface pressure is about 0.3 MPa.
  • the compression rate of the separator 40 is 20%, the compression surface pressure is about 0.6 MPa.
  • the compression rate of the separator 40 is 25%, the compression surface pressure is about 1.1 MPa.
  • the compression rate of the separator 40 is 30%, the compression surface pressure is about 1.9 MPa.
  • the compression rate of the separator 40 is 35%, the compression surface pressure is about 3.3 MPa.
  • the positive electrode 36 is formed on the first surface 34 c of the electrode plate 34, and the negative electrode 38 is formed on the second surface 34 d of the electrode plate 34 to obtain the bipolar electrode 32.
  • the bipolar electrode 32 is stacked via the separator 40 to obtain the stacked body 30.
  • sticker part 52 is formed in the peripheral part 34a of the electrode plate 34 of each bipolar electrode 32 by hot press or injection molding.
  • the second seal portion 54 is formed by, for example, injection molding.
  • the second seal portion 54 can be formed by pouring a resin material of the second seal portion 54 having fluidity into the mold.
  • the first seal portion 52 that is a part of the resin portion 50 is formed before the lamination step, and the second seal portion 54 that is the remaining portion of the resin portion 50 is formed after the lamination step.
  • an electrolytic solution is injected into the resin part 50 through an injection port or the like.
  • the storage module 12 is manufactured by sealing the injection port.
  • a plurality of power storage modules 12 are stacked via the conductive plate 14.
  • a positive electrode terminal 24 and a negative electrode terminal 26 are connected in advance to the conductive plates 14 located at both ends in the stacking direction.
  • a pair of restraint plates 16A and 16B are respectively disposed at both ends in the stacking direction via the insulating film 22, and the restraint plates 16A and 16B are connected to each other using the bolt 18 and the nut 20.
  • a restraint load compression force
  • the distance between the restraining plates 16A and 16B can be adjusted so that the compression rate of the separator 40 becomes the above-described predetermined compression rate.
  • power storage device 10 shown in FIG. 1 is manufactured.
  • a compressive force is applied to the portion where the positive electrode 36, the separator 40, and the negative electrode 38 are provided by the constraining structure 16 including the constraining plates 16A and 16B. If the compression rate of the separator 40 is greater than 0% and less than 40%, deformation of the restraint plates 16A and 16B due to fluctuations in the internal pressure of the cells and relaxation of the compression amount (that is, crushing amount) of the separator 40 occur simultaneously. That is, the compression state of the separator 40 reduces the internal pressure fluctuation.
  • the range of the compression rate is a range suitable for the separator 40 made of a porous resin.
  • the compression rate range suitable for the separator 40 made of porous resin By setting the compression rate range suitable for the separator 40 made of porous resin, load fluctuations on the restraining plates 16A and 16B are suitably suppressed. This leads to a reduction in the stress amplitude of the restraining plates 16A and 16B.
  • the separator 40 When the separator 40 is not compressed (when it is not crushed, that is, when the compression rate is 0%), the stress amplitude tends to increase (see FIG. 5). Therefore, the said structure is advantageous from a viewpoint of the fatigue
  • the compression rate of the separator 40 is too large, due to the surface pressure received from the compressed separator 40, a load higher than that when the internal pressure of the cell is increased is applied to the restraining plates 16A and 16B (see FIG. 4). ). This is disadvantageous from the viewpoint of fatigue of the restraining plates 16A and 16B. Further, the deformation criteria of the restraining plates 16A and 16B may be exceeded. By making the compression rate of the separator 40 less than 40%, these various problems that may occur with respect to the restraining plates 16A and 16B are solved.
  • the separator 40 may be separated from the bipolar electrode 32 (see FIG. 5).
  • the distance between the bipolar electrodes 32 cannot be controlled, and the ion conduction distance may become extremely long. These phenomena are not preferable because they increase the resistance in the power storage module 12. Therefore, when the compressibility of the separator 40 is 10% or more, the separation phenomenon of the separator 40 from the bipolar electrode 32 can be prevented, and an increase in resistance can be prevented. As a result, a desired output can be maintained (see FIG. 6).
  • the compression rate of the separator 40 is 30% or less, a plate thickness in an appropriate range can be set with respect to the assumed internal pressure of the cell.
  • the plate thickness in an appropriate range is such that the constraining plate does not deform with respect to the assumed internal pressure (it does not deform as far as the separator 40 is separated) and satisfies the desired thickness from the viewpoint of miniaturization of the power storage device 10. Thickness.
  • the compression rate of the separator 40 when the compression rate of the separator 40 is increased too much, the gaps in the separator 40 are reduced, and the diffusion of the electrolytic solution may be hindered. Also from this viewpoint, when the compression rate of the separator is 30% or less, the electrolyte solution can be diffused without any problem, and a desired output can be maintained (see FIG. 6).
  • the size of the restraining plates 16A and 16B is increased due to the separation of the separator 40 and the increase in the surface pressure by the separator 40. , And the possibility of various problems such as poor diffusion of the electrolyte solution is more reliably reduced.
  • the separator 40 made of porous resin is used, so the above-described compression rate range is particularly suitable.
  • a nickel metal hydride secondary battery provided with a bipolar electrode since a deformable member such as a resin is not provided between the restraining plates 16A and 16B and the bipolar electrode 32, the influence of fluctuations in the internal pressure of the cell is great.
  • a case with a fixed shape may be provided for each cell, but a bipolar nickel-hydrogen secondary battery does not have such a case. Therefore, the pressure receiving area is large and stress is easily applied.
  • the bipolar electrode 32 tends to have a large coating area, and from this point of view, the influence of cell internal pressure fluctuations is large.
  • the management of the compression rate of the separator 40 has a great effect in terms of reliability and miniaturization in the bipolar nickel-hydrogen secondary battery.
  • the separator 40 made of a polymorphic resin can adjust the thickness variation of the first seal portion 52 and the distance between the electrode plates 34 and 34 by reducing the amount of compression after compression.
  • the first restraining member and the second restraining member are not limited to plate-like members such as restraining plates 16A and 16B. What is used as the first restraining member and the second restraining member as long as a structure that is provided at both ends in the stacking direction of the electricity storage module and can apply a compressive force to the electricity storage module is realized. Also good.
  • the compression rate of the separator 40 is always greater than 0% during normal operation of the power storage module 12.
  • the stress generated in the restraint structure 16 when the power storage module 12 is abnormal is less than the yield stress of the restraint plates 16A and 16B.
  • the following two criteria (3) and (4) are further satisfied regarding the compression rate of the separator 40 and the optimal setting of the restraining plates 16A and 16B.
  • (3) The initial minimum porosity of the separator 40 is 33% or more.
  • the stress generated in the restraint structure 16 during the normal operation of the power storage module 12 is less than the fatigue strength of the restraint plates 16A and 16B.
  • FIG. 7 is a diagram showing an example of the establishment range of the above four criteria.
  • the horizontal axis indicates the thickness of the separator before compression
  • the vertical axis indicates the thickness of the restraint plate.
  • the thickness of the separator after compression is 75 ⁇ m. Therefore, when the horizontal axis is converted into the compression rate of the separator, the range where the thickness of the separator before compression is 75 ⁇ m to 125 ⁇ m corresponds to the range where the compression rate of the separator is 0% to 40%.
  • the right region of the graph A is a region that satisfies the criterion (1)
  • the left region of the graph B is a region that satisfies the criterion (2).
  • the left region of the graph C is a region satisfying the criterion (3)
  • the left region of the graph D is a region satisfying the criterion (4).
  • a region satisfying all the four criteria is a portion indicated by a region R in FIG. Among the portions indicated by the region R, the compression rate and the restraint plate thickness of the separator indicated by the point Ra where the restraint plate thickness is the smallest are the optimum design conditions that satisfy the above criteria (1) to (4).
  • Criterion (1) relates to deformation of the constraining plate due to fluctuations in the internal pressure of the cell and relaxation of the compression amount of the separator.
  • the thickness of the restraint plate is reduced, the amount of deformation of the restraint plate due to fluctuations in the internal pressure of the cell is increased, so that the compression rate of the separator satisfying the criterion (1) is also increased.
  • the storage module is provided with an open valve when the internal pressure rises, the storage module is operating at an internal pressure within a predetermined range that is less than the operating pressure of the open valve. Refers to the case.
  • Criterion (2) relates to the yield stress of the restraint plate.
  • the criterion (1) is abnormal, for example, when the storage module is provided with an open valve at the time when the internal pressure increases, the internal pressure of the storage module reaches the operating pressure of the open valve.
  • Criterion (3) relates to the diffusion of electrolyte between cells.
  • the boundary line of the criterion (3) in FIG. 7 is shifted to the left side of the graph.
  • the boundary line of the criterion (3) in FIG. Shift to the right refers to the time when the power storage module is tightened by the restraint structure.
  • Criterion (4) relates to the fatigue strength of the restraint plate. When the fatigue strength setting is increased, the boundary line of the criterion (4) in FIG. 7 shifts to the left side of the graph, and when the fatigue strength setting is decreased, the boundary line of the criterion (4) in FIG. Shift to.
  • FIG. 8 is a diagram showing an example of the compression characteristics of the separator.
  • the horizontal axis indicates the surface pressure
  • the vertical axis indicates the compression rate.
  • a graph E in FIG. 8 shows a compression characteristic of a separator having a thickness of 70 ⁇ m
  • a graph F shows a compression characteristic of a separator having a thickness of 80 ⁇ m
  • a graph G shows a compression characteristic of the separator having a thickness of 90 ⁇ m.
  • These compression characteristics are obtained using an autograph based on the load and stroke of the autograph.
  • the basis weight of each separator is 31 g / m2. From these compression characteristics, it is understood that when the basis weight is the same, the surface pressure for the same compression rate can be controlled by changing the thickness of the separator.
  • the reaction force can be calculated by converting the surface pressure from the pressure receiving area applied to the restraining plate.
  • FIG. 9 is a diagram illustrating an example of the relationship between the thickness of the separator and the porosity.
  • the horizontal axis represents the separator thickness
  • the vertical axis represents the porosity
  • the change in the porosity when the thickness of the separator having a basis weight of 31 g / m 2 is increased is plotted. From the results shown in the figure, it is understood that the porosity can be controlled by changing the thickness of the separator when the basis weight is the same.
  • the restraint plate include carbon steel for machine structure represented by S45C.
  • the physical properties after quenching and tempering are, for example, Young's modulus 205 MPa, Poisson's ratio 0.3, yield stress 490 MPa, tensile strength 690 MPa, and fatigue strength 305 MPa.
  • the minimum compression rate of the separator 40 is always greater than 0% during normal operation of the power storage module 12, and the stress generated in the restraint structure 16 when the power storage module 12 is abnormal is caused by the restraint plate 16A.
  • the compression rate of the separator 40 and the thicknesses of the restraining plates 16A and 16B may be set under a range that is equal to or less than the yield stress of 16B.
  • the compression rate of the separator 40 may be set so that the thicknesses of the restraining plates 16A and 16B are minimized within the above range. In this case, the physique of the power storage device 10 with respect to the output can be reduced. Therefore, the power storage device 10 can be highly integrated.
  • the compression rate of the separator 40 and the thickness of the restraining plates 16A and 16B may be set so that the initial minimum porosity of the separator 40 is 33% or more.
  • the electrolyte solution can be diffused without any problem, and a desired output can be maintained. Further, it is possible to cause sufficient gas escape during gas generation.
  • the compressibility of the separator 40 and the thickness of the restraint plates 16 ⁇ / b> A and 16 ⁇ / b> B are set so that the stress generated in the restraint structure 16 during the normal operation of the power storage module 12 is less than the fatigue strength of the restraint plates 16 ⁇ / b> A and 16 ⁇ / b> B. Sato may be set. In this case, it is possible to prevent the restraint plates 16A and 16B from being fatigued by the reaction force from the compressed separator 40.
  • SYMBOLS 10 Power storage device, 12 ... Power storage module, 16 ... Restraint structure, 16A, 16B ... Restraint plate (first restraint member, second restraint member), 32 ... Bipolar electrode, 34 ... Electrode plate, 34a ... Peripheral part, 34c ... 1st surface, 34d ... 2nd surface, 36 ... positive electrode, 38 ... negative electrode, 40 ... separator, 50 ... resin part, 52 ... 1st seal

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacturing & Machinery (AREA)
  • Secondary Cells (AREA)
  • Cell Separators (AREA)

Abstract

L'invention concerne un dispositif de stockage (10) d'électricité comprenant : au moins un module de stockage d'électricité (12) dans lequel une pluralité d'électrodes bipolaires (32) sont stratifiées dans une direction de stratification, des séparateurs (40) étant intercalés entre eux ; et une structure de contrainte (16) qui comprend des éléments de contrainte (16A, 16B) qui sont disposés aux deux extrémités dudit module de stockage d'électricité (12) dans la direction de stratification, et qui applique une force de compression à une partie dudit module de stockage d'électricité (12) dans la direction de stratification, une électrode positive (36), un séparateur (40) et une électrode négative (38) étant prévus dans ladite partie. Chaque séparateur (40) qui est pris en sandwich entre l'électrode positive (36) et l'électrode négative (38), tout en étant disposé entre la pluralité d'électrodes bipolaires (32), est formé à partir d'une résine poreuse. Le taux de compression de chaque séparateur (40) comprimé par la structure de contrainte (16) est supérieur à 0 % mais inférieur à 40 %.
PCT/JP2017/044230 2016-12-27 2017-12-08 Dispositif de stockage d'énergie électrique WO2018123520A1 (fr)

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WO2020012891A1 (fr) * 2018-07-12 2020-01-16 株式会社豊田自動織機 Batterie au nickel-hydrure métallique
JP2020030948A (ja) * 2018-08-22 2020-02-27 株式会社豊田自動織機 蓄電モジュールの製造方法及び蓄電モジュール
JP2020030981A (ja) * 2018-08-23 2020-02-27 株式会社豊田自動織機 蓄電モジュール及び蓄電モジュールの製造方法
JP2020030950A (ja) * 2018-08-22 2020-02-27 株式会社豊田自動織機 蓄電モジュール
WO2020039763A1 (fr) * 2018-08-22 2020-02-27 株式会社豊田自動織機 Module de stockage d'énergie et procédé de fabrication de module de stockage d'énergie
JP2022189409A (ja) * 2021-06-11 2022-12-22 トヨタ自動車株式会社 電池システム
EP4300524A4 (fr) * 2021-04-01 2025-01-08 GS Yuasa International Ltd. Élément de stockage d'électricité

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JP2002075318A (ja) * 2000-08-30 2002-03-15 Matsushita Electric Ind Co Ltd 二次電池
JP2004523091A (ja) * 2001-07-11 2004-07-29 エレクトロ エナジー，インコーポレイティド 積層ウェハーセルのバイポーラ型電気化学バッテリー
JP2003123712A (ja) * 2001-10-12 2003-04-25 Matsushita Electric Ind Co Ltd 電解質を含む電気化学素子
JP2010198933A (ja) * 2009-02-25 2010-09-09 Toyota Motor Corp 電極板加圧装置
JP2011138761A (ja) * 2009-12-04 2011-07-14 Sony Corp セパレータおよび電池
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Publication number Priority date Publication date Assignee Title
WO2020012891A1 (fr) * 2018-07-12 2020-01-16 株式会社豊田自動織機 Batterie au nickel-hydrure métallique
JP2020030948A (ja) * 2018-08-22 2020-02-27 株式会社豊田自動織機 蓄電モジュールの製造方法及び蓄電モジュール
JP2020030950A (ja) * 2018-08-22 2020-02-27 株式会社豊田自動織機 蓄電モジュール
WO2020039763A1 (fr) * 2018-08-22 2020-02-27 株式会社豊田自動織機 Module de stockage d'énergie et procédé de fabrication de module de stockage d'énergie
JP7056464B2 (ja) 2018-08-22 2022-04-19 株式会社豊田自動織機 蓄電モジュールの製造方法及び蓄電モジュール
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JP2020030981A (ja) * 2018-08-23 2020-02-27 株式会社豊田自動織機 蓄電モジュール及び蓄電モジュールの製造方法
EP4300524A4 (fr) * 2021-04-01 2025-01-08 GS Yuasa International Ltd. Élément de stockage d'électricité
JP2022189409A (ja) * 2021-06-11 2022-12-22 トヨタ自動車株式会社 電池システム
JP7468462B2 (ja) 2021-06-11 2024-04-16 トヨタ自動車株式会社 電池システム

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