Battery module and battery pack including same

Abstract

A battery module according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked, a module frame that houses the battery cell stack, and a sliding plate disposed between adjacent battery cells among the plurality of battery cells.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2021 - 0112408, filed on August 25, 2021, and all of the contents disclosed in the document of the Korean Patent Application are incorporated herein by reference in their entirety. The present invention relates to a battery module and a battery pack including the same, and more particularly, to a battery module with enhanced safety and a battery pack including the same.

Background Art

[0002] With the development of technology and the increasing demand for mobile devices, the demand for secondary batteries as an energy source has been rapidly increasing. In particular, secondary batteries have attracted much attention not only as an energy source for mobile devices such as mobile phones, digital cameras, notebook computers, and wearable devices, but also for power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0003] For small mobile devices, one, two, three, or four battery cells are used per device, while for medium - to - large - sized devices such as automobiles, high - output and large - capacity are required. Therefore, medium - to - large - sized battery modules in which a large number of battery cells are electrically connected are used. Medium - to - large - sized battery modules are preferably manufactured in as small a size and weight as possible, so prismatic batteries, pouch - type batteries, etc., which can be stacked with a high degree of integration and have a small weight - to - capacity ratio, are mainly used as battery cells of medium - to - large - sized battery modules. On the other hand, the battery module may include a module frame in which the front and rear surfaces are open to accommodate the battery cell stack in the internal space to protect the battery cell stack from external impact, heat, or vibration.

[0004] FIG. 1 is an exploded perspective view of a conventional battery module. FIG. 2 is a perspective view showing a state in which the components constituting the battery module of FIG. 1 are combined. FIG. 3 is a cross - sectional view taken along the cutting line A - A' of FIG. 2.

[0005] Referring to FIGS. 1 to 3, a conventional battery module 10 includes a battery cell stack 12 in which a plurality of battery cells 11 are stacked in one direction, a module frame 25 that houses the battery cell stack 12, and end plates 15 that cover the front and rear surfaces of the battery cell stack 12. At this time, the module frame 25 includes a lower frame 30 that covers the lower part and both side surfaces of the battery cell stack 12, and an upper plate 40 that covers the upper surface of the battery cell stack 12. At the same time, a bus bar assembly 13 is formed between the battery cell stack 12 and the end plates 15.

[0006] Also, as shown in FIG. 3, a compression pad 20 is located between a pair of adjacent battery cells in the battery cell stack 12. Referring to FIGS. 2 and 3, the compression pad 20 included in the conventional battery module 10 can be in contact with one surface of the battery cell 11.

[0007] When the battery cell 11 swells, the battery cell stack 12 may apply stress to the lower frame 30 and the upper plate 40, which may reduce the rigidity of the module, making it difficult to ensure the stability of the battery module. At this time, the compression pad 20 can partially absorb the swelling phenomenon, but there is a limit in controlling the large amount of swelling generated during the charge and discharge process only with the compression pad 20. In addition, since there may be differences in the thickness and tolerances of the battery cells 11, or unpressurized portions may occur, it is difficult to maintain the initial pressing force only with the compression pad 20 in the case of a battery module that requires ensuring the initial pressing force. In particular, in the case of a battery cell made of pure silicon (Si) or an all-solid-state battery cell, a certain pressing force needs to be maintained initially, and a large amount of swelling occurs during the charge and discharge process compared to conventional battery cells. Therefore, a structure that can appropriately control this is required, and an additional structure for minimizing the occurrence of swelling needs to be formed to ensure the rigidity of the module.

[0008] Accordingly, different from the prior art, there is a need to develop a battery module and a battery pack that have an initial pressure and can control the internal pressure by absorbing a large amount of swelling phenomenon generated during charge and discharge.

Summary of the Invention

Problems to be Solved by the Invention

[0009] The problem to be solved by the present invention is to provide a battery module that can maintain an initial pressure and absorb a large amount of cell swelling, and a battery pack including the same.

[0010] The problem to be solved by the present invention is not limited to the problems described above, and problems not mentioned will be clearly understood by those having ordinary knowledge in the technical field to which the present invention pertains from the present specification and the attached drawings.

Means for Solving the Problems

[0011] A battery module according to an embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked, a module frame that houses the battery cell stack, and a sliding plate disposed between adjacent battery cells among the plurality of battery cells.

[0012] The sliding plate includes a first sliding plate and a second sliding plate, and the first sliding plate and the second sliding plate are formed to be separated from each other between the adjacent battery cells.

[0013] The battery module includes a connecting member formed between the first sliding plate and the second sliding plate, and the connecting member can connect the first sliding plate and the second sliding plate.

[0014] The connecting member can include a spring member.

[0015] A plurality of the connecting members are formed between the first sliding plate and the second sliding plate.

[0016] The battery module includes shaft members formed at upper and lower portions of the battery cell laminate, and the shaft members are connected to end portions of the sliding plates.

[0017] The module frame includes a frame member covering lower and both side portions of the battery cell laminate, and an upper plate covering an upper portion of the battery cell laminate, and the shaft members are formed in parallel with the upper plate.

[0018] A plurality of the shaft members are formed, and the shaft members are fixedly installed on respective side surfaces of the frame member, and the shaft members are respectively connected to the first sliding plate and the second sliding plate.

[0019] The shaft member may include a first shaft member connected to the first sliding plate and a second shaft member connected to the second sliding plate.

[0020] The first shaft member may include a first-1 shaft member connected to an upper end portion of the first sliding plate and a first-2 shaft member connected to a lower end portion of the first sliding plate, and the second shaft member may include a second-1 shaft member connected to an upper end portion of the second sliding plate and a second-2 shaft member connected to a lower end portion of the second sliding plate.

[0021] The battery module according to another embodiment of the present invention may include a mounting portion formed on a side surface portion of the module frame.

[0022] The mounting portion is formed along a longitudinal direction of the battery cell.

[0023] A battery pack according to still another embodiment of the present invention includes the battery module described above.

Advantages of the Invention

[0024] According to an embodiment of the present invention, it is possible to maintain an initial pressing force through the structure of a sliding plate and a connecting member interposed between a pair of adjacent battery cells, and to control the swelling phenomenon generated by charge and discharge.

[0025] In particular, it is possible to control the pressure change due to the occurrence of cell swelling through a sliding plate, a connecting member, and a shaft member.

[0026] Also, it is possible to suppress the occurrence of swelling through a mounting portion formed on the module frame.

[0027] The effects of the present invention are not limited to the effects described above, and effects not mentioned will be clearly understood by those having ordinary knowledge in the technical field to which the present invention pertains from this specification and the attached drawings.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0029] Hereinafter, embodiments of the present invention will be described in detail so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement it. However, the present invention can be realized in various different forms and is not limited to the embodiments described herein.

[0030] In order to clearly explain the present invention, parts that are unnecessary for the explanation are omitted, and the same reference numerals are given to the same or similar components throughout the specification.

[0031] Also, the sizes and thicknesses of the respective configurations shown in the drawings are arbitrarily shown for convenience of explanation, and thus the present invention is not necessarily limited to those shown in the drawings. In the drawings, the thicknesses are shown enlarged in order to clearly represent various layers and regions. And, in the drawings, for convenience of explanation, the thicknesses of some layers and regions are exaggerated.

[0032] Also, when a part such as a layer, a film, a region, or a plate is said to be "on" another part, this includes not only the case where it is "directly on" the other part but also the case where there are other parts in between. Conversely, when a part is said to be "directly on" another part, it means that there are no other parts in between. Further, being "on" the reference part means being located above or below the reference part, and does not necessarily mean being located "upward" in the opposite direction of gravity.

[0033] Also, throughout the specification, when a part "includes" a certain component, this means that other components can be further included, rather than excluding other components, unless otherwise stated to the contrary.

[0034] Furthermore, throughout the specification, when referring to "on a plane", it means when viewing the target part from above, and when referring to "in a cross-section", it means when viewing the cross-section obtained by vertically cutting the target part from the side.

[0035] Hereinafter, with reference to FIGS. 4, 5, and 7, a battery module according to an embodiment of the present invention will be described.

[0036] FIG. 4 is a perspective view of the battery module of the present invention. FIG. 5 is a cross-sectional view taken parallel to the xz plane along the cutting line B-B' of FIG. 4, and is a cross-sectional view of the battery module according to an embodiment of the present invention. FIG. 7 is a perspective view showing one battery cell included in the battery cell stack of FIG. 5.

[0037] Referring to FIGS. 4 and 5, the battery module 100 according to this embodiment includes a battery cell stack 120 in which a plurality of battery cells 110 are stacked, a module frame 200 that houses the battery cell stack 120, and end plates 150 that cover the front and rear surfaces of the battery cell stack 120.

[0038] The battery cell 110 is preferably a pouch-type battery cell. For example, referring to FIG. 7, the battery cell 110 according to this embodiment has a structure in which two electrode leads 111 and 112 protrude from one end 114a and the other end 114b of the battery body 113 facing each other. The battery cell 110 is manufactured by adhering one end 114a and the other end 114b of the battery case 114 and both side surfaces 114c connecting them in a state where an electrode assembly (not shown) is housed in the battery case 114. In other words, the battery cell 110 according to this embodiment has a total of three sealing portions 114sa, 114sb, and 114sc, and the sealing portions 114sa, 114sb, and 114sc are sealed by a method such as heat fusion, and the remaining other side portion is a connecting portion 115. The direction between one end 114a and the other end 114b of the battery case 114 is defined as the longitudinal direction of the battery cell 110, and the direction between one side portion 114c connecting one end 114a and the other end 114b of the battery case 114 and the connecting portion 115 can be defined as the width direction of the battery cell 110.

[0039] The connecting portion 115 is a region that extends long along one edge of the battery cell 110, and a protruding portion 110p of the battery cell 110 is formed at an end of the connecting portion 115. The protruding portion 110p is formed at at least one of both ends of the connecting portion 115 and can protrude in a direction perpendicular to the direction in which the connecting portion 115 extends. The protruding portion 110p can be located between the connecting portion 115 and one of the sealing portions 114sa and 114sb at one end portion 114a and the other end portion 114b of the battery case 114.

[0040] The battery case 114 generally has a laminate structure of a resin layer / metal thin film layer / resin layer. For example, when the surface of the battery case is made of an O (oriented) -nylon layer, when a large number of battery cells are laminated to form a medium or large-sized battery module, there is a tendency to be slippery due to an external impact. Therefore, in order to prevent this and maintain a stable laminated structure of the battery cells, an adhesive member such as an adhesive type adhesive such as a double-sided tape or a chemical adhesive bonded by a chemical reaction during adhesion is attached to the surface of the battery case to form the battery cell laminate 120.

[0041] The module frame 200 includes a frame member 300 whose upper surface, front surface, and rear surface are open to cover the lower portion and both side portions of the battery cell laminate 120, and an upper plate 400 that covers the upper portion of the battery cell laminate 120. However, the module frame 200 is not limited to this, and may be replaced with a frame of another shape such as an L-shaped frame or a monoframe that surrounds the battery cell laminate 120 except for the front and rear surfaces. The battery cell laminate 120 housed inside the module frame 200 can be physically protected via the module frame 200. At this time, the frame member 300 can include a bottom portion 300a that supports the lower portion of the battery cell laminate 120, and side surface portions 300b that extend upward from both end portions of the bottom portion 300a, respectively.

[0042] The upper plate 400 can cover the open upper surface of the module frame 200. The end plate 150 can cover the front and rear surfaces of the battery cell stack 120 that are open in the module frame 200. The end plate 150 can be joined to the front and rear end corners of the upper plate 400 and the front and rear end corners of the module frame 200 by welding.

[0043] Conventional battery modules have attempted to absorb cell swelling by including compression pads interposed between battery cells. However, in the case of battery cells containing pure silicon (Si) and all-solid-state battery cells with a very large degree of cell swelling, there has been a limit to absorbing cell swelling with only conventional compression pads. In particular, although the battery cells also require maintenance of a certain initial pressing force, there has been a limit to forming the initial pressing force with only conventional compression pads.

[0044] Therefore, referring to FIG. 5, the battery module 100 according to this embodiment includes a sliding plate 500 disposed between adjacent battery cells 110 among the plurality of battery cells 110. At this time, the sliding plate 500 can include a first sliding plate 510 and a second sliding plate 520, and the first sliding plate 510 and the second sliding plate 520 are formed to be separated from each other between adjacent battery cells 110.

[0045] The battery module according to this embodiment can include a connecting member 600 formed between the first sliding plate 510 and the second sliding plate 520. At this time, the connecting member 600 can be selected without limitation within a range that does not limit the movement of the sliding plate 500. Specifically, the connecting member 600 can include a spring member. The connecting member 600 can connect the first sliding plate 510 and the second sliding plate 520.

[0046] At this time, the connecting member 600 can form an initial pressing force by being formed between the first sliding plate 510 and the second sliding plate 520. In particular, when cell swelling occurs, the connecting member 600 is compressed to enable the movement of the first sliding plate 510 and the second sliding plate 520, thereby achieving the effect of being able to control the pressure due to cell swelling.

[0047] Therefore, at least one or more connecting members 600 are formed between the first sliding plate 510 and the second sliding plate 520. More specifically, by forming a plurality of them, it is possible to achieve the maintenance of the initial pressing force due to the elastic force of the connecting member 600 and the absorption effect of cell swelling.

[0048] On the other hand, for maintaining the initial pressing force, a fixing member may be formed together with the connecting member 600, and the fixing member is removed after fixing the position of the connecting member 600 for forming the initial pressing force.

[0049] On the other hand, the battery module 100 according to this embodiment may include shaft members 700 formed on the upper and lower portions of the battery cell stack 120. In particular, the shaft member 700 is connected to the end portion of the sliding plate 500. At this time, for this connection, a hole may be formed in the sliding plate 500 and the shaft member 700 may be inserted and fixed through the hole, or an adhesive member may be further formed between the sliding plate 500 and the shaft member 700. Also, without being limited to the above method, the sliding plate 500 and the shaft member 700 can be connected in various ways.

[0050] On the one hand, when the shaft member 700 is formed in the battery module 100 according to this embodiment, the shaft member 700 is formed parallel to the upper plate 400. Specifically, referring to FIGS. 4 and 5, the shaft member 700 is formed along the x-axis and -x-axis directions, which are the stacking directions of the battery cells. At the same time as being formed along the said directions, the shaft member 700 is formed parallel to the upper plate 400.

[0051] Also, a plurality of shaft members 700 are formed. The shaft members 700 are fixedly installed on each side surface portion 300b of the frame member, and the shaft members 700 are respectively connected to the first sliding plate 510 and the second sliding plate 520.

[0052] That is, referring to FIG. 5, the shaft member 700 can include a first shaft member 710 connected to the first sliding plate 510 and a second shaft member 720 connected to the second sliding plate 520. At this time, the first shaft member 710 can include a first-1 shaft member 711 connected to the upper end portion of the first sliding plate 510 and a first-2 shaft member 712 connected to the lower end portion of the first sliding plate 510. Also, the second shaft member 720 can include a second-1 shaft member 721 connected to the upper end portion of the second sliding plate 520 and a second-2 shaft member 722 connected to the lower end portion of the second sliding plate 520. For this reason, shaft members 700 are formed at both end portions of the sliding plate 500, and when cell swelling occurs, the sliding plate 500 can move smoothly without being biased in one direction.

[0053] When swelling of the battery cell 110 occurs on the battery module 100 according to this embodiment, the battery cell 110 adjacent to the sliding plate 500 can apply pressure to the sliding plate 500. At this time, the connecting member 600 located between the sliding plates 500 is compressed by the pressure, and due to this compression, the sliding plate 500 moves in the direction of the connecting member 600. At the same time, the shaft member 700 connected to the sliding plate 500 can extend due to the movement of the sliding plate 500.

[0054] Therefore, by the connecting member 600 being compressed by the pressure applied to the sliding plate 500, it is possible to absorb cell swelling. At the same time, by the movement of the sliding plate 500 and the extension of the shaft member 700, it is possible to control the pressure caused by the swelling. Further, by minimizing the cell swelling phenomenon and increasing the absorption effect of the swelling, the stability of the battery module can be improved.

[0055] Hereinafter, with reference to FIG. 6, a battery module according to another embodiment of the present invention will be described. At this time, since there is content that overlaps with the content described above, only the parts different from the content described above will be described.

[0056] FIG. 6 is a cross-sectional view of a battery module according to another embodiment of the present invention.

[0057] Referring to FIG. 6, the battery module according to this embodiment can include a mounting portion 800 formed on a side surface portion of the module frame 200. Specifically, the mounting portion 800 is formed on the side surface portion 300b of the frame member 300.

[0058] At this time, referring to FIGS. 4 and 6, the mounting portion 800 is formed on the side surface portion 300b along the y-axis and -y-axis directions which are the longitudinal directions of the battery cell 110. That is, the mounting portion 800 is formed in the direction of the cell swelling phenomenon occurring along the longitudinal direction of the battery cell 110. Further, the mounting portion 800 is formed to have a shape that repeatedly protrudes and indents from the side surface portion 300b.

[0059] By forming the mounting portion 800 as described above, the effect of minimizing the possibility of deformation of the module frame 200 due to cell swelling can be achieved. In particular, the mounting portion 800 formed along the cell swelling direction can achieve the effect of suppressing the occurrence of cell swelling.

[0060] Hereinafter, with reference to FIG. 8, a battery pack according to still another embodiment of the present invention will be described.

[0061] FIG. 8 is an exploded perspective view of a battery pack according to still another embodiment of the present invention.

[0062] Referring to FIG. 8, the battery pack 1000 according to this embodiment can be formed by packaging one or more of the above-described battery modules in a pack case. In particular, it can be formed by being packaged by an upper pack case 1100 and a lower pack case 1200, and may have a structure in which a battery management system (BMS) for managing the temperature, voltage, etc. of the battery and a cooling device are additionally packaged. At this time, the battery pack according to this embodiment can improve stability by including a structure capable of absorbing and minimizing cell swelling.

[0063] In addition, the battery module and the battery pack including the same described above are applicable to various devices. Such devices can be applied to transportation means such as electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto, and is applicable to various devices that can use the battery module and the battery pack including the same, which also belong to the scope of the rights of the present invention.

[0064] As described above, the preferred embodiments of the present invention have been described in detail. However, the scope of the rights of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention defined in the following claims also belong to the scope of the rights of the present invention.

Explanation of Reference Numerals

[0065] 110: Battery cell 120: Battery cell laminate 200: Module frame 300: Frame member 400: Upper plate 500: Sliding plate 600: Connecting member 700: Shaft member 800: Mounting portion 1000: Battery pack

Claims

1. a battery cell stack in which a plurality of battery cells are stacked; a module frame that houses the battery cell stack; a sliding plate disposed between adjacent battery cells among the plurality of battery cells, the sliding plate includes a first sliding plate and a second sliding plate; the first sliding plate and the second sliding plate are spaced apart from each other between the adjacent battery cells, the battery module includes a connecting member formed between the first sliding plate and the second sliding plate, the connecting member connects the first sliding plate and the second sliding plate, the battery module includes shaft members formed on upper and lower parts of the battery cell stack, The shaft member is connected to a distal end of the sliding plate, the module frame includes a frame member that covers a lower portion and both sides of the battery cell stack, and an upper plate that covers an upper portion of the battery cell stack, The shaft member is formed parallel to the upper plate, The shaft member is formed in plurality, The shaft member is fixed to each side surface of the frame member, the shaft member is connected to the first sliding plate and the second sliding plate, the shaft member includes a first shaft member coupled to the first sliding plate and a second shaft member coupled to the second sliding plate, a battery module in which, when swelling occurs in the battery cell adjacent to one of the first sliding plate and the second sliding plate, the battery cell in which swelling has occurred applies pressure to the one of the first sliding plate and the second sliding plate, the connecting member is compressed by the pressure, and the one of the first sliding plate and the second sliding plate moves in a direction toward the connecting member due to the compression, and at the same time, one of the first shaft member and the second shaft member connected to the one of the first sliding plate and the second sliding plate extends.

2. The battery module according to claim 1 , wherein the connecting member includes a spring member.

3. The battery module of claim 1 , wherein the connecting member is a plurality of connecting members formed between the first sliding plate and the second sliding plate.

4. the first shaft member includes a first-1 shaft member connected to an upper end portion of the first sliding plate and a first-2 shaft member connected to a lower end portion of the first sliding plate; 2. The battery module of claim 1, wherein the second shaft member includes a 2-1 shaft member connected to an upper end portion of the second sliding plate and a 2-2 shaft member connected to a lower end portion of the second sliding plate.

5. The battery module according to claim 1 , further comprising a mounting portion formed on a side portion of the module frame.

6. The battery module according to claim 5 , wherein the mounting portion is formed along a longitudinal direction of the battery cell.

7. A battery pack comprising the battery module according to claim 1.

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