KR102813933B1 - Battery module and battery pack including the same - Google Patents

Abstract

According to one embodiment of the present invention, a battery module includes a battery cell stack in which a plurality of battery cells including electrode leads are stacked; a bus bar connected to the electrode leads; a sensing assembly positioned on the battery cell stack; and a connecting member connecting the bus bar and the sensing assembly, wherein the connecting member includes a contact portion that contacts the bus bar and a spring portion that brings the contact portion into close contact with the bus bar, and the spring portion is positioned at the center of the contact portion.

Description

BATTERY MODULE AND BATTERY PACK INCLUDING THE SAME

The present invention relates to a battery module and a battery pack including the same, and more specifically, to a battery module including a plurality of battery cells connected to each other through a bus bar, and a battery pack including the same.

Secondary batteries, which have high applicability according to product group and electrical characteristics such as high energy density, are widely used in portable devices as well as electric or hybrid vehicles driven by electric power sources, and power storage devices. These secondary batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency enhancement, not only because they can drastically reduce the use of fossil fuels, but also because they do not generate any by-products from energy use.

Currently commercialized secondary batteries include nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are receiving attention due to their advantages such as the fact that they have almost no memory effect compared to nickel-based secondary batteries, can be freely charged and discharged, have a very low self-discharge rate, and have high energy density.

These lithium secondary batteries mainly use lithium oxide and carbon material as positive and negative active materials, respectively. The lithium secondary battery comprises an electrode assembly in which positive and negative plates, each coated with the positive and negative active materials, are arranged with a separator between them, and an outer material, i.e., a battery case, that seals and stores the electrode assembly together with an electrolyte.

In general, lithium secondary batteries can be classified into square secondary batteries in which the electrode assembly is built into a metal can and pouch-type secondary batteries in which the electrode assembly is built into a pouch of an aluminum laminate sheet, depending on the shape of the outer packaging material.

While small mobile devices use one to three battery cells per device, medium and large devices such as automobiles require high output and large capacity. Accordingly, medium and large battery modules that electrically connect multiple battery cells are used.

It is desirable for medium- and large-sized battery modules to be manufactured with as small a size and weight as possible, so square batteries and pouch-type batteries that can be stacked with high integration and have small weight per capacity are mainly used as battery cells for medium- and large-sized battery modules.

Meanwhile, when configuring a battery pack by connecting multiple battery cells in series/parallel, it is common to configure a battery module composed of multiple battery cells and configure the battery pack by adding other components to at least one of the battery modules.

Such a battery module may be configured to include a battery cell stack in which a plurality of battery cells are stacked, a bus bar connecting the plurality of battery cells, and a sensing assembly positioned on the battery cell stack to measure the voltage and temperature of the battery cells. At this time, a method such as welding was used in the past to connect the bus bar and the sensing assembly. Accordingly, such an additional welding process was required in the manufacturing process. In addition, for such welding, one end of the sensing assembly had to be positioned outside the bus bar, and the welded portion had to be exposed to the outside.

The purpose of embodiments of the present invention is to provide a battery module and a battery pack including the same with improved manufacturing processability by enabling simpler connection of a bus bar and a sensing assembly.

However, the problems to be solved by the embodiments of the present invention are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention.

According to one embodiment of the present invention, a battery module comprises: a battery cell stack in which a plurality of battery cells including electrode leads are stacked; a bus bar connected to the electrode leads; a sensing assembly positioned on the battery cell stack; and a connecting member connecting the bus bar and the sensing assembly, wherein the connecting member comprises a contact portion that contacts the bus bar and a spring portion that brings the contact portion into close contact with the bus bar, and the spring portion is positioned at the center of the contact portion.

The above contact portion may be plate-shaped, and the above spring portion may be a plate spring.

The above spring portion can be bent by protruding in the opposite direction to the direction in which the bus bar is located.

The above contact portion and the above spring portion can be integrated.

The above spring portion may have one end connected to the contact portion, and the remaining ends excluding the one end may be spaced apart from the contact portion.

The above battery module includes busbar frames positioned at the front and rear sides of the battery cell stack, respectively, and the busbar is mounted on the busbar frame, and the connecting member can be positioned between the busbar and the busbar frame.

The above contact portion can contact the bus bar, and the above spring portion can contact the bus bar frame.

The above busbar frame may include a detachment prevention member protruding in the direction of the connecting member.

The above-mentioned detachment prevention part may include an outer detachment prevention part arranged along the outer periphery of the spring part.

A through hole is formed in the above spring portion, and the detachment prevention portion may include an inner detachment prevention portion passing through the through hole.

The above connecting member includes at least one connecting portion that connects the connecting member and the sensing assembly, and the connecting portion can be bent after penetrating the sensing assembly.

The above sensing assembly may be a flexible printed circuit (FPC) or a flexible flat cable (FFC).

According to embodiments of the present invention, a bus bar and a sensing assembly can be connected more simply without welding by using a connecting member including a spring portion, thereby improving manufacturing processability and reducing costs.

Figure 1 is an exploded perspective view of a battery module according to one embodiment of the present invention.
Figure 2 is a perspective view of a battery cell included in the battery module of Figure 1.
FIG. 3 is a front view of a battery cell stack and a first bus bar frame included in the battery module of FIG. 1.
Figure 4 is an enlarged partial view of part “A” of Figure 3.
Figure 5 is a cross-sectional view taken along the cutting line B-B' of Figure 4.
Figure 6 is a partial view of part “C” of Figure 3 viewed from a different angle.
Figure 7 is a perspective view of a connecting member according to one embodiment of the present invention.
FIG. 8 is a partial diagram illustrating a connecting member and a first bus bar frame according to a modified embodiment of the present invention.
Fig. 9 is a partial view showing the connecting member of Fig. 8 and the first bus bar frame in contact with each other.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts irrelevant to the description are omitted, and the same reference numerals are used for identical or similar components throughout the specification.

In addition, the size and thickness of each component shown in the drawing are arbitrarily shown for the convenience of explanation, so the present invention is not necessarily limited to what is shown. In the drawing, the thickness is shown enlarged to clearly express several layers and regions. And in the drawing, the thickness of some layers and regions is shown exaggeratedly for the convenience of explanation.

Also, when we say that a part such as a layer, film, region, or plate is "over" or "on" another part, this includes not only cases where it is "directly over" the other part, but also cases where there is another part in between. Conversely, when we say that a part is "directly over" another part, it means that there is no other part in between. Also, when we say that a part is "over" or "on" a reference part, it means that it is located above or below the reference part, and does not necessarily mean that it is located "over" or "on" the opposite direction of gravity.

Additionally, throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

Additionally, throughout the specification, when we say "in plan", we mean when the target portion is viewed from above, and when we say "in cross section", we mean when the target portion is viewed from the side in a cross-section cut vertically.

Figure 1 is an exploded perspective view of a battery module according to one embodiment of the present invention.

Referring to FIG. 1, a battery module (100) according to one embodiment of the present invention includes a battery cell stack (200) in which a plurality of battery cells (110) including electrode leads (150) are stacked; a bus bar (300) connected to the electrode leads (150); a sensing assembly (400) positioned on the battery cell stack (200); and a connecting member connecting the bus bar (300) and the sensing assembly (400). The connecting member will be described in detail later with reference to FIGS. 3 to 7.

FIG. 2 is a perspective view of a battery cell (110) included in the battery module (100) of FIG. 1.

Referring to Fig. 2, it is preferable that the battery cell (110) is a pouch-type battery cell. For example, the battery cell (110) according to the present embodiment has a structure in which two electrode leads (150) face each other and protrude from one end (114a) and the other end (114b) of the battery body (113). More specifically, the electrode leads (150) are connected to an electrode assembly (not shown) and protrude from the electrode assembly (not shown) to the outside of the battery cell (110).

Meanwhile, the battery cell (110) can be manufactured by bonding the two ends (114a, 114b) of the battery case (114) and one end (114c) connecting them while the electrode assembly (not shown) is stored in the battery case (114). In other words, the battery cell (110) according to the present embodiment has a total of three sealing parts (114sa, 114sb, 114sc), and the sealing parts (114sa, 114sb, 114sc) have a structure in which they are sealed by a method such as heat fusion, and the remaining other end can be formed as a connecting part (115).

Referring back to FIG. 1, the battery cells (110) of FIG. 2 can be stacked along the y-axis direction to form a battery cell stack (200). Accordingly, the electrode leads (150) of each of the plurality of battery cells (110) protrude toward the front (x-axis direction) and the rear (opposite to the x-axis) of the battery cell stack (200).

Depending on the direction in which the electrode lead (150) protrudes, busbar frames (310, 320) may be positioned at the front and rear (x-axis direction and direction opposite to the x-axis) of the battery cell stack (200), respectively. Specifically, a first busbar frame (310) may be positioned at the front (x-axis direction) of the battery cell stack (200), and a second busbar frame (320) may be positioned at the rear (x-axis direction) of the battery cell stack (200).

FIG. 3 is a front view of the battery cell stack (200) and the first busbar frame (310) included in the battery module of FIG. 1. Specifically, it is a view of the first busbar frame (310) combined with the battery cell stack (200) as viewed from the opposite direction of the x-axis.

Referring to FIGS. 1 to 3 together, at least one bus bar (300) is mounted on a first bus bar frame (310), and an electrode lead (150) protruding from a battery cell (110) may pass through a slit formed in the first bus bar frame (310) and then be bent to be connected to the bus bar (300). There is no particular limitation on the method of this connection, but they may be connected by welding each other. In this way, by connecting the electrode leads (150) of the battery cells (110) to the bus bar (300), the battery cells (110) may be electrically connected to each other.

Meanwhile, in addition to the busbar (300), the first busbar frame (310) may have a part of a sensing assembly (400) positioned on the battery cell stack (200) and a module connector (410) connected to the sensing assembly (400).

The sensing assembly (400) may be a flexible printed circuit (FPC) or a flexible flat cable (FFC).

This sensing assembly (400) senses the voltage and temperature of a plurality of battery cells (110) and transmits electrical information to a BMS (Battery Manufacturing System) through a module connector (410), thereby detecting phenomena such as overvoltage, overcurrent, and overheating of each battery cell (110). Accordingly, the sensing assembly (400) may include a voltage sensing circuit and a temperature sensing circuit.

FIG. 4 is a partial view showing an enlarged portion of "A" of FIG. 3, FIG. 5 is a cross-sectional view taken along the cutting line B-B' of FIG. 4, FIG. 6 is a partial view of "C" of FIG. 3 viewed from a different angle, and FIG. 7 is a perspective view of a connecting member (500) according to one embodiment of the present invention. In this case, the bus bar is omitted in FIG. 6 for convenience of explanation.

Referring to FIGS. 4 to 7, the battery module (100) according to the present embodiment includes a connecting member (500) that connects a bus bar (300) and a sensing assembly (400). It is preferable that the connecting member (500) includes a material that can conduct electricity, and voltage information of the battery cells (110) can be transmitted to the sensing assembly (400) via the bus bar (300) through the connecting member (500).

The connecting member (500) includes a contact portion (510) that comes into contact with the bus bar (300) and a spring portion (520) that presses the contact portion (510) against the bus bar (300). The spring portion (520) may be located at the center of the contact portion (510). In other words, the contact portion (510) may be located along the outer periphery of the spring portion (520).

The contact portion (510) may be plate-shaped, and the spring portion (520) may be a plate spring. The contact portion (510) may be configured as a plate to form a wide contact area with the bus bar (300), and the spring portion (520) may be configured as a plate spring to effectively bring the contact portion (510) into close contact with the bus bar (300) in a limited space. To this end, the spring portion (520) of the plate spring may be protruded and bent in a direction opposite to the direction in which the bus bar (300) is located (in the direction opposite to the x-axis).

Meanwhile, as illustrated in FIGS. 6 and 7, it is preferable that the contact portion (510) and the spring portion (520) according to the present embodiment be integrated. That is, rather than providing a separate elastic member, the connecting member (500) itself may be provided with the spring portion (520) of the plate spring. Accordingly, a limited space can be efficiently utilized, and electrical connection between the bus bar (300) and the sensing assembly (400) is possible simply by positioning the connecting member (500) between the bus bar (300) and the first bus bar frame (310). In addition, the elastic force of the spring portion (520) can be evenly applied to the contact portion (510).

More specifically, the spring portion (520) may have one end (521) connected to the contact portion (510), and the remaining end (522) excluding one end (521) may be spaced from the contact portion (510). With this structure, the spring portion (520) may be formed integrally with the contact portion (510) and may be bent by protruding in a direction opposite to the direction in which the bus bar (300) is located (in the direction opposite to the x-axis).

In addition, the connecting member (500) may include at least one protruding connecting portion (530) for connection with the sensing assembly (400). Specifically, the connecting portion (530) formed in the connecting member (500) may be bent after penetrating the sensing assembly (400), thereby connecting the connecting member (500) and the sensing assembly (400).

In the past, methods such as welding were used to connect the bus bar (300) and the sensing assembly (400). Accordingly, this additional welding process was required in the manufacturing process. In addition, for this welding, one end of the sensing assembly (400) had to be positioned outside the bus bar (300), and the welding portion had to be exposed to the outside.

On the other hand, according to the present embodiment, electrical connection between the bus bar (300) and the sensing assembly (400) is possible simply by positioning the connecting member (500) between the bus bar (300) and the first bus bar frame (310), so that a conventional welding process is unnecessary. Accordingly, when manufacturing the battery module (100), the manufacturing process can be improved and the cost can be reduced.

In addition, since the connecting member (500) is positioned between the bus bar (300) and the first bus bar frame (310), one end of the sensing assembly (400) and the connecting member (500) can naturally be positioned on the inner side rather than the outer side of the bus bar (300), thereby enabling protection for one end of the sensing assembly (400) and the connecting member (500).

Referring again to FIG. 5, as described above, the busbar (300) may be mounted on the first busbar frame (310), and the connecting member (500) may be positioned between the busbar (300) and the first busbar frame (310). At this time, the contact portion (510) may contact the busbar (300), and the spring portion (520) may contact the first busbar frame (310).

Specifically, the busbar (300) is inserted into the fixing portion (311) of the first busbar frame (310) so that the busbar (300) can be stably mounted without being separated in the x-axis direction. In addition, the spring portion (520) contacts the first busbar frame (310) and brings the contact portion (510) into close contact with the busbar (300). The busbar (300) fixed by the fixing portion (311) is not pushed in the x-axis direction even by the elastic force of the spring portion (520), and all parts of the contact portion (510) come into strong contact with the busbar (300), so that current conduction is achieved between the busbar (300) and the connecting member (500).

Meanwhile, although the description was made based on the first busbar frame (310), according to the present embodiment, the configuration of the connecting member (500) can be applied equally to the second busbar frame (320).

In addition, although the description is based on the bus bar (300) located at the far right in Fig. 1, the configuration of the connecting member (500) can be applied equally to other bus bars (300).

Hereinafter, a connecting member and a first busbar frame according to a modified embodiment of the present invention will be described with reference to FIGS. 8 and 9. For convenience of explanation, the busbar is omitted in FIGS. 8 and 9.

FIG. 8 is a partial diagram illustrating a connecting member (500a) and a first busbar frame (310a) according to a modified embodiment of the present invention, and FIG. 9 is a partial diagram showing the connecting member (500a) and the first busbar frame (310a) of FIG. 8 in contact with each other.

Referring to FIGS. 8 and 9, the connecting member (500a) according to the present embodiment includes a contact portion (510a) and a spring portion (520a), is connected to the sensing assembly (400), and can be positioned between a bus bar (not shown) and a first bus bar frame (310a). Since this overlaps with the previously described content, further description is omitted.

At this time, the first bus bar frame (310a) may include a detachment prevention member (330) protruding toward the connecting member (500a).

The detachment prevention part (330) may include an outer detachment prevention part (331) arranged along the outer periphery of the spring part (520a).

Specifically, the spring portion (520a) can be integrated with the contact portion (510a), one end (521a) can be connected to the contact portion (510a), and the remaining ends (522a) except for one end (521a) can be spaced apart from the contact portion (510a).

The outer detachment prevention member (331) may be arranged along the remaining end (522a) of the outer periphery of the spring member (520a). The outer detachment prevention member (331) may be arranged along at least a portion of the remaining end (522a), but it is preferable to be arranged along the entire remaining end (522a) as shown in FIG. 8.

In addition, the outer detachment prevention parts (331) may be configured to be spaced apart at regular intervals, but are preferably arranged to be connected as in Fig. 8. That is, the outer detachment prevention parts (331) may be arranged to be connected along the outer periphery of the spring part (520a).

Through this external separation prevention member (331), the connecting member (500a) located between the bus bar and the first bus bar frame (310a) can be prevented from being separated from a designated position due to external impact or vibration applied to the battery module.

Meanwhile, a through hole (523) may be formed in the spring portion (520a), and the detachment prevention portion (330) may include an inner detachment prevention portion (332) passing through the through hole (523).

When the spring portion (520a) of the connecting member (500a) comes into contact with the first bus bar frame (310a), the inner separation prevention portion (332) protruding toward the connecting member (500a) can pass through the through hole (523).

Through this inner separation prevention member (332), the connecting member (500a) located between the bus bar and the first bus bar frame (310a) can be prevented from being separated from a designated position due to external impact or vibration applied to the battery module.

As shown in Fig. 9, the connecting member (500a) can be stably fixed by an outer separation prevention member (331) arranged along the outer periphery of the spring member (520a). In addition, the connecting member (500a) can be stably fixed by an inner separation prevention member (332) passing through the through hole (523).

The detachment prevention unit (330) according to the present embodiment may include an outer detachment prevention unit (331) or an inner detachment prevention unit (332), and may include both an outer detachment prevention unit (331) and an inner detachment prevention unit (332).

Meanwhile, referring back to FIG. 1, the battery module (100) according to the present embodiments may include a module frame and an end plate (700) for accommodating a battery cell stack (200). As shown in FIG. 1, the module frame may be a mono frame (600) in which the front (x-axis direction) and the rear (opposite to the x-axis direction) are open, and the upper surface (z-axis direction), the lower surface (opposite to the z-axis direction), and both sides (y-axis direction and the opposite direction) are integrated.

The battery cell stack (200) can be housed in a mono frame (600) with an open front (x-axis direction) and a back (opposite to the x-axis direction), and the open front and back can be covered by an end plate (700). There is no particular limitation on the joining of the mono frame (600) and the end plate (700), but they can be welded to each other.

The entire body, including the battery cell stack (200), can be stored and protected in the mono frame (600) and end plate (700).

Meanwhile, when the sensing assembly (400) and the battery cell stack (200) are housed in the mono frame (600), a cover plate (900) may be placed on the sensing assembly (400) to prevent damage to the sensing assembly (400).

Although not specifically illustrated, the module frame in the present invention may include a U-shaped frame having a bottom surface (opposite to the z-axis) and both sides (in the y-axis direction and its opposite direction) integrated therewith, and an upper plate covering the open top of the U-shaped frame.

One or more battery modules according to the above-described embodiment can be mounted together with various control and protection systems such as a BMS (Battery Management System) and a cooling system to form a battery pack.

The above battery module or battery pack can be applied to various devices. Specifically, it can be applied to means of transportation such as electric bicycles, electric cars, and hybrids, but is not limited thereto, and can be applied to various devices that can use secondary batteries.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

100: Battery module
110: Battery cell
200: Battery cell stack
300: Busbar
310: 1st busbar frame
320: 2nd busbar frame
400: Sensing Assembly
500: Connection part
510: Contact
520: Spring part

Claims (13)

A battery cell stack comprising a plurality of battery cells including electrode leads;
A bus bar connected to the above electrode leads;
A sensing assembly positioned on the above battery cell stack; and
Including a connecting member connecting the above bus bar and the above sensing assembly,
The above connecting member includes a contact portion that comes into contact with the bus bar and a spring portion that presses the contact portion against the bus bar.
The spring portion is located at the center of the contact portion, and the contact portion is located along the outer periphery of the spring portion,
A battery module in which one end of the spring portion is connected to the contact portion, and the remaining ends excluding the one end are spaced apart from the contact portion. In paragraph 1,
A battery module in which the above contact portion is plate-shaped and the above spring portion is a plate spring. In paragraph 2,
A battery module in which the spring portion protrudes and bends in the opposite direction to the direction in which the bus bar is located. In paragraph 1,
A battery module in which the above contact portion and the above spring portion are integrated. delete In paragraph 1,
It includes a bus bar frame positioned at the front and rear of the battery cell stack, respectively.
The busbar is mounted on the above busbar frame,
The above connecting member is a battery module located between the bus bar and the bus bar frame. In Article 6,
A battery module wherein the contact portion is in contact with the bus bar and the spring portion is in contact with the bus bar frame. In Article 6,
The above busbar frame is a battery module including a detachment prevention member protruding in the direction of the connecting member. In Article 8,
A battery module wherein the above-mentioned separation prevention part includes an outer separation prevention part arranged along the outer periphery of the spring part. In Article 8,
A through hole is formed in the above spring part,
The above detachment prevention part is a battery module including an inner detachment prevention part passing through the through hole. In paragraph 1,
The above connecting member includes at least one connecting portion that connects the connecting member and the sensing assembly,
The above-mentioned joint is a battery module that is bent after penetrating the above-mentioned sensing assembly. In paragraph 1,
The above sensing assembly is a battery module which is a flexible printed circuit (FPC) or a flexible flat cable (FFC). A battery pack comprising one or more battery modules according to claim 1.

Images