Battery pack

Abstract

To improve the strength of battery packs and to reduce the size of battery packs.SOLUTION: A battery pack 1 has a plurality of battery modules 10. Each battery module 10 has a plurality of battery cells 100 and structures 200. In each battery module 10, a plurality of battery cells 100 and structures 200 are arranged side by side. The plurality of structures 200 of the plurality of battery modules 10 are coupled to each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a battery pack. [Background technology]

[0002] In recent years, various battery packs have been developed. A battery pack includes a battery module and a housing that houses the battery module. Each battery module includes a plurality of battery cells.

[0003] Patent Document 1 describes a power supply device. The power supply device includes a plurality of battery packs. Some of the battery packs are arranged vertically. A sponge is disposed between the battery packs arranged vertically.

[0004] Patent Document 2 describes a battery pack. The battery pack includes a plurality of battery cells and a housing that houses the plurality of battery cells. The plurality of battery cells are grouped into a first battery group and a second battery group. The housing has a beam disposed between the first battery group and the second battery group. The beam forms a path for discharging heat and gas.

[0005] Patent Document 3 describes a battery pack. The battery pack includes a housing in which a plurality of battery module accommodating spaces are formed. The housing has separation beams that separate the plurality of battery module accommodating spaces from each other. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2015-115285 A [Patent Document 2] US Patent Application Publication No. 2022 / 0123423 [Patent Document 3] China Utility Model No. 210489699 Summary of the Invention [Problem to be solved by the invention]

[0007] A battery pack may require a relatively high strength. In order to improve the strength of the battery pack, a reinforcing material such as a frame surrounding the battery module may be provided inside the housing. However, if a reinforcing material is simply provided inside the housing, it may be difficult to reduce the size of the battery pack.

[0008] One example of an object of the present invention is to improve the strength of a battery pack while reducing the size of the battery pack. Other objects of the present invention will become apparent from the description of this specification. [Means for solving the problem]

[0009] One aspect of the present invention is as follows. 1. A battery pack having a plurality of battery modules; Each battery module includes a plurality of battery cells and a structure. In each battery module, the plurality of battery cells and the structure are arranged side by side, A battery pack, wherein a plurality of the structures of the plurality of battery modules are coupled to one another. 2. The battery pack further includes a housing for housing the plurality of battery modules; 1. The battery pack described in 1., wherein the housing and the multiple structures of the multiple battery modules are connected to each other. 3. A battery pack described in 1. or 2., wherein at least a portion of the structure is located between at least one battery cell and at least one other battery cell. Effect of the Invention

[0010] According to the above aspect of the present invention, it is possible to improve the strength of the battery pack while reducing the size of the battery pack. [Brief description of the drawings]

[0011] [Figure 1]FIG. 2 is a top view of the battery pack according to the embodiment. [Diagram 2] 2 is a cross-sectional view taken along line AA in FIG. 1. [Diagram 3] FIG. 13 is a top view of a battery pack according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments and modifications of the present invention will be described with reference to the drawings. In all the drawings, similar components are given similar reference numerals and descriptions thereof will be omitted as appropriate.

[0013] Fig. 1 is a top view of a battery pack 1 according to an embodiment of the present invention, and Fig. 2 is a cross-sectional view taken along line AA in Fig. 1.

[0014] In each figure, the X direction, the Y direction, and the Z direction are shown for the purpose of explanation. The X direction indicates the front-rear direction of the battery pack 1. The Y direction is perpendicular to the X direction. The Y direction indicates the left-right direction of the battery pack 1. The Z direction is perpendicular to both the X direction and the Y direction. The Z direction indicates the up-down direction of the battery pack 1. The arrows pointing to the X direction, the arrows pointing to the Y direction, and the arrows pointing to the Z direction indicate the front, left, and up directions of the battery pack 1, respectively. In FIG. 1, the white circle with a black dot indicating the Z direction indicates that the arrow pointing to the Z direction extends from the back of the paper to the front. In FIG. 2, the white circle with an X indicating the X direction indicates that the arrow pointing to the X direction extends from the front of the paper to the back. The relationship between the X direction, the Y direction, and the Z direction and the front-rear direction, the left-right direction, and the up-down direction of the battery pack 1 is not limited to the example of the explanation according to the embodiment.

[0015] Hereinafter, as necessary, the side pointed to by an arrow indicating the X direction will be referred to as the +X side, and the side opposite the side pointed to by the arrow indicating the X direction will be referred to as the -X side. Hereinafter, as necessary, the side pointed to by an arrow indicating the Y direction will be referred to as the +Y side, and the side opposite the side pointed to by the arrow indicating the Y direction will be referred to as the -Y side. Hereinafter, as necessary, the side pointed to by an arrow indicating the Z direction will be referred to as the +Z side, and the side opposite the side pointed to by the arrow indicating the Z direction will be referred to as the -Z side.

[0016] As shown in FIG. 1, the battery pack 1 includes a plurality of battery modules 10 and a pack housing 20.

[0017] As shown in Fig. 1, in the embodiment, four battery modules 10 are arranged in two rows and two columns in the X direction and the Y direction. Hereinafter, as necessary, the battery module 10 located on the +X side and the -Y side among the four battery modules 10 will be referred to as a first battery module 10a, the battery module 10 located on the +X side and the +Y side among the four battery modules 10 will be referred to as a second battery module 10b, the battery module 10 located on the -X side and the -Y side among the four battery modules 10 will be referred to as a third battery module 10c, and the battery module 10 located on the -X side and the +Y side among the four battery modules 10 will be referred to as a fourth battery module 10d. However, the number and arrangement of the battery modules 10 are not limited to those described in the embodiment.

[0018] The pack housing 20 houses a plurality of battery modules 10. Specifically, the pack housing 20 has a bottom plate 22, a frame 24, and a top plate (not shown). In the example shown in FIG. 1, the bottom plate 22 has a substantially rectangular plate shape having a pair of sides parallel to the X direction and another pair of sides parallel to the Y direction when viewed from the Z direction. However, the shape of the bottom plate 22 is not limited to the shape shown in FIG. 1. The plurality of battery modules 10 are disposed on the surface side of the bottom plate 22 on the +Z side. The frame 24 is disposed on the surface side of the bottom plate 22 on the +Z side. When viewed from the Z direction, the frame 24 surrounds the four battery modules 10. In the example shown in FIG. 1, the frame 24 has a substantially rectangular frame shape having a pair of sides parallel to the X direction and another pair of sides parallel to the Y direction when viewed from the Z direction. However, the shape of the frame 24 is not limited to the shape shown in FIG. 1. The top plate covers the plurality of battery modules 10 from the +Z side.

[0019] 1, each battery module 10 has a plurality of battery cells 100, a structure 200, and a module housing 300. Hereinafter, as necessary, the structure 200 of the first battery module 10a will be referred to as a first structure 200a, the structure 200 of the second battery module 10b will be referred to as a second structure 200b, the structure 200 of the third battery module 10c will be referred to as a third structure 200c, and the structure 200 of the fourth battery module 10d will be referred to as a fourth structure 200d.

[0020] The Y-direction dimension of each battery cell 100 is the longitudinal dimension of each battery cell 100. The Z-direction dimension of each battery cell 100 is the transverse dimension of each battery cell 100. The X-direction dimension of each battery cell 100 is the thickness direction dimension of each battery cell 100. The shape of each battery cell 100 is not limited to this example.

[0021] Each battery cell 100 includes a battery element and an exterior material that seals the battery element. The battery element has at least one positive electrode, at least one negative electrode, and at least one separator. For example, a plurality of positive electrodes and a plurality of negative electrodes are alternately stacked in the X direction. At least a portion of the separator is located between the positive electrodes and the negative electrodes adjacent in the X direction. For example, each of a plurality of sheet-like separators may be located between the positive electrodes and the negative electrodes adjacent in the X direction. Alternatively, one sheet-like separator may have a zigzag shape that passes through the region between the positive electrodes and the negative electrodes adjacent in the X direction. Alternatively, the positive electrode, the negative electrode, and the separator may be wound so that the separator is disposed between the positive electrode and the negative electrode. In one example, the positive electrode, the negative electrode, and the separator are wound in a state where both sides of one of the positive electrode and the negative electrode are covered by the separator. In another example, a stack including a plurality of unit stacks including a positive electrode, a separator, and a negative electrode in this order may be wound. However, the winding structure of the positive electrode, negative electrode, and separator is not limited to these examples.

[0022] The battery cell 100 may be an all-solid-state battery. In an all-solid-state battery, a solid electrolyte layer is provided in a portion corresponding to a separator. An all-solid-state battery does not contain an electrolyte. Hereinafter, unless otherwise specified, the battery cell 100 will be described as a battery cell containing an electrolyte.

[0023] The structure 200 is formed of a material having a predetermined mechanical strength, such as metal or resin. The structure 200 may be solid or at least partially hollow. In each battery module 10, the structure 200 extends in the Y direction. When viewed from the Z direction, the dimension of the structure 200 in the Y direction is the dimension in the longitudinal direction of the structure 200. When viewed from the Z direction, the dimension of the structure 200 in the X direction is the dimension in the lateral direction of the structure 200. The shape of the structure 200 is not limited to this example.

[0024] In each battery module 10, the multiple battery cells 100 and the structure 200 are arranged side by side in the X direction. Specifically, in each battery module 10, at least a portion of the structure 200 is located between at least one battery cell 100 and at least one other battery cell 100 in the X direction. Therefore, the structure 200 of each battery module 10 can insulate at least one battery cell 100 located on the -X side of the structure 200 from at least one other battery cell 100 located on the +X side of the structure 200. Therefore, even if abnormal heat generation occurs in at least one battery cell 100, the structure 200 can suppress heat conduction between the at least one battery cell 100 located on the -X side of the structure 200 and at least one other battery cell 100 located on the +X side of the structure 200.

[0025] In the example shown in FIG. 1, in each battery module 10, the structure 200 is located between six battery cells 100 arranged side by side in the X direction and other six battery cells 100 arranged side by side in the X direction. Therefore, the structure 200 is located at approximately the center in the X direction of the stacked structure including 12 battery cells 100 and structures 200. However, the number and positions of the multiple battery cells 100 and structures 200 are not limited to the number and positions shown in FIG. 1 and FIG. 2. As long as the multiple battery cells 100 and structures 200 are arranged side by side in a predetermined direction such as the X direction, at least one structure 200 can be arranged at any position relative to the multiple battery cells 100. In one example, the structure 200 may be positioned offset in the X direction from approximately the center of the battery module 10 in the X direction. In this example, the structure 200 may be positioned on the -X side of the battery cell 100 located at the end on the -X side, or on the +X side of the battery cell 100 located at the end on the +X side. Alternatively, in each battery module 10, the multiple structures 200 may be positioned so as to be shifted from one another in the X direction.

[0026] In the example shown in FIG. 1, in each battery module 10, the multiple battery cells 100 and the structures 200 are arranged side by side at approximately equal pitches in the X direction. Specifically, the dimensions of each battery cell 100 in the X direction and the dimensions of the structures 200 in the X direction are approximately equal. Therefore, the multiple battery cells 100 and the structures 200 are easily arranged side by side at approximately equal pitches in the X direction. However, the dimensions of each battery cell 100 in the X direction and the dimensions of the structures 200 in the X direction may be different from each other. Alternatively, or in addition, the pitches of the multiple battery cells 100 and the structures 200 in the X direction may be different depending on the positions of each battery module 10 in the X direction. The battery cells 100 adjacent to each other in the X direction may be in contact with each other, or may be arranged side by side with a member such as a compression pad (not shown). The battery cells 100 and the structures 200 adjacent to each other in the X direction may also be in contact with each other, or may be arranged side by side with a member such as a compression pad (not shown).

[0027] In each battery module 10, the multiple battery cells 100 are electrically connected in series, in parallel, or in a combination of series and parallel. The multiple battery cells 100 are electrically connected to each other via positive and negative terminals (not shown) arranged on opposite sides of each battery cell 100 in the Y direction, or via positive and negative terminals (not shown) arranged on one of the +Y side and -Y side of each battery cell 100. For example, in each battery module 10, the multiple battery cells 100 located on the -X side of the structure 200 may be connected in series, and the multiple battery cells 100 located on the +X side of the structure 200 may be directly connected to the multiple battery cells 100 located on the -X side of the structure 200. Alternatively, in each battery module 10, the multiple battery cells 100 located on the -X side of the structure 200 may be connected in parallel, and the multiple battery cells 100 located on the +X side of the structure 200 may be connected in parallel, and the multiple battery cells 100 located on the -X side of the structure 200 and the multiple battery cells 100 located on the +X side of the structure 200 may be connected in series.

[0028] In each battery module 10, the module housing 300 houses a plurality of battery cells 100 and a structure 200. In the example shown in Fig. 1, in the first battery module 10a, a portion on the +Y side of the first structure 200a protrudes toward the +Y side from a portion on the +Y side of the module housing 300, and in the second battery module 10b, a portion on the -Y side of the second structure 200b protrudes toward the -Y side from a portion on the -Y side of the module housing 300. The same applies to the structures 200 and module housing 300 of the third battery module 10c and the fourth battery module 10d.

[0029] In the embodiment, the first structure 200a and the second structure 200b are connected to each other. Specifically, as shown in FIG. 2, the first structure 200a includes a first protrusion 202a, and the second structure 200b includes a second structure 200b. The first protrusion 202a is located at the end of the first structure 200a on the +Y side. The second protrusion 202b is located at the end of the second structure 200b on the -Y side. The bottom plate 22, the first protrusion 202a, and the second protrusion 202b are fastened to each other by the fastener 30 in a state in which the first protrusion 202a and the second protrusion 202b overlap each other in the Z direction. Thus, the pack housing 20, the first structure 200a, and the second structure 200b are connected to each other via the fastener 30. In the example shown in FIG. 2, the fastener 30 penetrates the bottom plate 22, the first protrusion 202a, and the second protrusion 202b in the Z direction. The fastener 30 is, for example, a combination of a bolt and a nut. However, the method of connecting the pack housing 20, the first structure 200a, and the second structure 200b to each other is not limited to the method shown in FIG.

[0030] In the embodiment, the first structure 200a and the second structure 200b are beams extending from one of the first battery module 10a to the other of the second battery module 10b with the first protrusion 202a and the second protrusion 202b coupled to each other. Therefore, the first structure 200a and the second structure 200b are reinforcing members that reinforce the strength of the multiple battery cells 100 of the first battery module 10a and the multiple battery cells 100 of the second battery module 10b. Therefore, the first structure 200a and the second structure 200b can contribute to improving the strength of the battery pack 1 with the first protrusion 202a and the second protrusion 202b coupled to each other. Therefore, the strength of the plurality of battery cells 100 of the first battery module 10a and the plurality of battery cells 100 of the second battery module 10b can be improved by the first structure 200a and the second structure 200b without requiring a reinforcing material such as a frame surrounding the first battery module 10a in the area surrounded by the frame 24 as viewed from the Z direction or a frame surrounding the second battery module 10b in the area surrounded by the frame 24 as viewed from the Z direction. Thus, the battery pack 1 can be made smaller in size than when a reinforcing material such as the above-mentioned frame is used in the area surrounded by the frame 24 as viewed from the Z direction. Therefore, in the embodiment, it is possible to achieve both improvement in the strength of the battery pack 1 and miniaturization of the battery pack 1 as compared to when a reinforcing material such as the above-mentioned frame is used in the area surrounded by the frame 24 as viewed from the Z direction.

[0031] In the embodiment, as described with reference to Fig. 2, the pack housing 20, the first structure 200a, and the second structure 200b are coupled to each other. Therefore, compared with a case where the first structure 200a and the second structure 200b are not coupled to the pack housing 20, the first structure 200a and the second structure 200b can further reinforce the strength of the multiple battery cells 100 of the first battery module 10a and the multiple battery cells 100 of the second battery module 10b. However, the first structure 200a and the second structure 200b do not have to be coupled to the pack housing 20.

[0032] In the above description, the coupling of the first structure 200a and the second structure 200b has been described. The third structure 200c and the fourth structure 200d are also coupled to each other in the same manner as the first structure 200a and the second structure 200b, for example, in the same manner as the example described using FIG. 2. The third structure 200c and the fourth structure 200d may be coupled to the pack housing 20 in the same manner as the first structure 200a and the second structure 200b, in the same manner as the example described using FIG. 2. Therefore, the third structure 200c and the fourth structure 200d can also contribute to improving the strength of the battery pack 1 in the same manner as the first structure 200a and the second structure 200b.

[0033] 3 is a top view of a battery pack 1A according to a modified example. The battery pack 1A according to the modified example is similar to the battery pack 1 according to the embodiment, except for the following points.

[0034] The battery pack 1A according to the modification includes a plurality of battery modules 10 arranged in the Y direction. In each battery module 10, a plurality of battery cells 100 and structures 200 are arranged in the X direction. In the battery pack 1A according to the modification, a plurality of structures 200 of a plurality of battery modules 10 are arranged in the Y direction. The portions between the battery modules 10 adjacent to each other in the Y direction of the plurality of structures 200 according to the modification are connected to each other, for example, in the same manner as in the example described with reference to FIG. 2. In the same manner as in the example shown in FIG. 2, the plurality of structures 200 according to the modification may be connected to the pack housing 20. In the same manner as in the embodiment, the plurality of structures 200 according to the modification can also contribute to improving the strength of the battery pack 1A in a state in which the portions between the battery modules 10 adjacent to each other in the Y direction of the plurality of structures 200 are connected to each other. Therefore, in the modification, as in the embodiment, it is possible to achieve both improvement in the strength of the battery pack 1A and miniaturization of the battery pack 1, compared to the case in which a reinforcing material such as a frame surrounding each battery cell 100 is used within the area surrounded by the frame 24 when viewed from the Z direction.

[0035] Although the embodiment and modified examples of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various configurations other than those described above can also be adopted.

[0036] For example, in the embodiment, each battery module 10 has a module housing 300. However, each battery module 10 does not have to have the module housing 300. When each battery module 10 does not have the module housing 300, the multiple battery cells 100 are directly housed in the pack housing 20 without a housing such as the module housing 300. [Explanation of symbols]

[0037] 1,1A battery pack, 10 battery module, 10a first battery module, 10b second battery module, 10c third battery module, 10d fourth battery module, 20 pack housing, 22 bottom plate, 24 frame, 30 fastener, 100 battery cell, 200 structure, 200a first structure, 200b second structure, 200c third structure, 200d fourth structure, 202a first protrusion, 202b second protrusion, 300 module housing

Claims

1. A battery module is provided. Each battery module includes a plurality of battery cells and a structure. In each battery module, the plurality of battery cells and the structure are arranged side by side, A battery pack, wherein a plurality of the structures of the plurality of battery modules are coupled to one another.

2. The battery pack further includes a housing that houses the plurality of battery modules. The battery pack according to claim 1 , wherein the housing and the plurality of structures of the plurality of battery modules are coupled to one another.

3. The battery pack according to claim 1 or 2, wherein at least a portion of the structure is located between at least one battery cell and at least one other battery cell.

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