Battery pack

Abstract

To provide a battery pack including a bus bar with a suitable shape for connecting between bus bar modules in a case of employing a bus bar module structure in a Cell-to-Pack structure.SOLUTION: A third bus bar 200 employed in this battery pack includes a first region 210 electrically connected to a first battery cell and existing on a first bus bar module side, a second region 220 electrically connected to a second battery cell and existing on a second bus bar module side, and a third region 230 provided at a position bridging the first bus bar module and the second bus bar module and connecting the first region 210 and the second region 220.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present technology relates to battery packs. [Background technology]

[0002] Chinese Utility Model No. 213782118 (Patent Document 1) discloses a cell-to-pack structure in which a stack containing multiple battery cells is stored directly in a case without using end plates and bind bars (module structure) to restrain the multiple battery cells. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Chinese Utility Model No. 213782118 Summary of the Invention [Problem to be solved by the invention]

[0004] In a structure in which a busbar module, which is formed by modularizing multiple busbars housed in a plate member, is mounted on a stack of multiple battery cells, the stack including the multiple battery cells includes internal busbars that connect adjacent battery cells within the same stack, and transition busbars that connect between stacks.

[0005] In a structure in which a busbar module is mounted on top of a stack of multiple battery cells, the transition busbars that connect the busbar modules must be designed to bridge the gap between the busbar modules, and therefore must be designed with an optimal shape, compared to the shape of the internal busbars.

[0006] The objective of this technology is to provide a battery pack that includes bus bars with an optimal shape for connecting between bus bar modules when a bus bar module structure is adopted in a cell-to-pack structure. [Means for solving the problem]

[0007] The present technology provides the following battery pack.

[0008] [1] A first stack including a plurality of first battery cells arranged in a first direction; a second stack adjacent to the first stack in a second direction perpendicular to the first direction and including a plurality of second battery cells arranged in the first direction; a case having side walls facing the first stack and the second stack in the first direction and housing the first stack and the second stack; a first bus bar electrically connecting the plurality of first battery cells, a first bus bar module housing the first bus bar and disposed on the first stack; a second bus bar electrically connecting the plurality of second battery cells, and a second bus bar module housing the second bus bar and disposed on the second stack; a third bus bar arranged along a second direction to bridge between the first bus bar module and the second bus bar module, and electrically connecting one of the first battery cells selected from the first stack and one of the second battery cells selected from the second stack, wherein the third bus bar includes a first region electrically connected to the first battery cell and located on the first bus bar module side, a second region electrically connected to the second battery cell and located on the second bus bar module side, and a third region arranged at a position bridging between the first bus bar module and the second bus bar module, and connecting the first region and the second region.

[0009] [2] The battery pack described in [1], wherein one of the first battery cells selected from the first stack is located at the end facing the side wall, and one of the second battery cells selected from the second stack is located on the same side as one of the first battery cells selected from the first stack.

[0010] [3] A battery pack according to [1] or [2], wherein when viewed along a third direction perpendicular to the first direction and the second direction, the third region has a convex shape positioned above the first region and the second region.

[0011] [4] A battery pack described in any one of [1] to [3], including a positioning mechanism inserted between the first stack and the second stack to position the first stack and the second stack in the X-axis direction, and the third region being located above the positioning mechanism. [Effects of the Invention]

[0012] According to the present technology, when a bus bar module structure is adopted in a cell-to-pack structure, it is possible to provide a battery pack including bus bars having an optimal shape for connecting between bus bar modules. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is an exploded perspective view of the battery pack according to the embodiment. [Figure 2] FIG. 2 is a perspective view of a battery cell according to an embodiment. [Figure 3] FIG. 2 is a top view of a plate member of the bus bar module according to the embodiment. [Figure 4] FIG. 2 is a perspective view illustrating a structure around a bus bar of the bus bar module according to the embodiment. [Figure 5] 10 is a plan view showing the structure of the bus bar module according to the embodiment before a third bus bar is provided. FIG. [Figure 6] 10 is a plan view showing the structure of the bus bar module according to the embodiment after a third bus bar has been provided. FIG. [Figure 7] FIG. 4 is a perspective view showing the structure of a third bus bar according to the embodiment. [Figure 8] 4 is a partial enlarged view showing a positioning mechanism provided between a first stack and a second stack according to the embodiment. [Figure 9]10 is a partially enlarged view of the vicinity of a top surface region of a third bus bar according to the embodiment. FIG. [Figure 10] FIG. 10 is a perspective view showing a third bus bar in another embodiment. [Figure 11] FIG. 10 is a perspective view showing a third bus bar in still another embodiment. [Figure 12] FIG. 10 is a perspective view showing a third bus bar in still another embodiment. [Figure 13] FIG. 10 is a perspective view showing a third bus bar in still another embodiment. [Figure 14] FIG. 10 is a perspective view showing a third bus bar in still another embodiment. [Figure 15] FIG. 10 is a perspective view showing a third bus bar in still another embodiment. [Figure 16] FIG. 10 is a perspective view showing a third bus bar in still another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present technology will be described. Note that the same or corresponding parts are denoted by the same reference characters, and description thereof may not be repeated.

[0015] In the embodiments described below, when numbers, amounts, etc. are mentioned, the scope of the present technology is not necessarily limited to those numbers, amounts, etc., unless otherwise specified. Furthermore, in the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. Furthermore, the present technology is not necessarily limited to those that achieve all of the effects mentioned in the present embodiments.

[0016] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a certain feature is included, other features may or may not be included.

[0017] Furthermore, when geometric terms and terms expressing positional and directional relationships are used in this specification, such as "parallel," "orthogonal," "45° diagonal," "coaxial," and "along," these terms allow for manufacturing errors and slight variations. When terms expressing relative positional relationships, such as "upper side" and "lower side," are used in this specification, these terms are used to indicate relative positional relationships in a single state, and the relative positional relationships can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

[0018] In this specification, "battery" is not limited to lithium-ion batteries, but may include other batteries such as nickel-metal hydride batteries and sodium-ion batteries. In this specification, "battery packs" can be installed in hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). However, the use of "battery cells" is not limited to in-vehicle use.

[0019] Fig. 1 is an exploded perspective view of a battery pack 1. As shown in Fig. 1, the battery pack 1 includes a stack 10 including a plurality of battery cells 100 (see Fig. 2) arranged in the Y-axis direction (first direction), a case 20 that houses the stack 10, and a bus bar module 30 arranged on the stack 10.

[0020] The laminate 10 includes a first laminate 10A, a second laminate 10B, and a third laminate 10C. The first laminate 10A and the second laminate 10B are adjacent to each other in the X-axis direction (second direction). The second laminate 10B and the third laminate 10C are adjacent to each other in the X-axis direction.

[0021] The case 20 has side walls 21 that face the first stack 10A, the second stack 10B, and the third stack 10C in the Y-axis direction. The side walls 21 directly support the first stack 10A, the second stack 10B, and the third stack 10C from both sides in the Y-axis direction. In this way, the battery pack 1 according to this embodiment employs a cell-to-pack structure in which the stack 10, which includes a plurality of battery cells 100, is housed directly in the case.

[0022] The busbar module 30 includes a first busbar module 30A arranged on the first laminate 10A, a second busbar module 30B arranged on the second laminate 10B, and a third busbar module 30C arranged on the third laminate 10C. In this embodiment, the first busbar module 30A, the second busbar module 30B, and the third busbar module 30C have the same shape, but may have different shapes.

[0023] 2 is a perspective view showing the configuration of the battery cells 100 that make up the first stack 10A, the second stack 10B, and the third stack 10C. As shown in FIG. 2, the battery cells 100 have a rectangular shape. The battery cells 100 have electrode terminals 110, a housing 120, and a gas release valve 130.

[0024] The electrode terminals 110 are formed on the housing 120. The electrode terminals 110 include a positive terminal 111 and a negative terminal 112 as two electrode terminals 110 aligned along an X-axis direction (second direction) perpendicular to a Y-axis direction (first direction). The positive terminal 111 and the negative terminal 112 are spaced apart from each other in the X-axis direction.

[0025] The housing 120 has a substantially rectangular parallelepiped shape. An electrode assembly and an electrolyte (not shown) are housed in the housing 120. The housing 120 has an upper surface 121, a lower surface 122, a first side surface 123, a second side surface 124, and a third side surface 125.

[0026] The upper surface 121 is a plane perpendicular to the Z-axis direction. The electrode terminals 110 are disposed on the upper surface 121. The lower surface 122 faces the upper surface 121 along the Z-axis direction (third direction) perpendicular to the Y-axis direction (first direction) and the X-axis direction (second direction).

[0027] Each of the first side surface 123 and the second side surface 124 is made of a plane perpendicular to the Y-axis direction. Each of the first side surface 123 and the second side surface 124 has the largest area among the multiple side surfaces of the housing 120. Each of the first side surface 123 and the second side surface 124 has a rectangular shape when viewed in the Y-axis direction. Each of the first side surface 123 and the second side surface 124 has a rectangular shape when viewed in the Y-axis direction, with the X-axis direction being the longitudinal direction and the Z-axis direction being the lateral direction.

[0028] The multiple battery cells 100 are stacked such that the first side surfaces 123 and the second side surfaces 124 of the battery cells 100 adjacent to each other in the Y-axis direction face each other. As a result, the positive electrode terminals 111 and the negative electrode terminals 112 are arranged alternately in the Y-axis direction in which the multiple battery cells 100 are stacked.

[0029] Gas exhaust valve 130 is provided on top surface 121. When the internal pressure of housing 120 rises to a predetermined value or higher due to gas generated inside housing 120, gas exhaust valve 130 opens and exhausts the gas to the outside of housing 120.

[0030] Next, the basic configuration of the busbar module 30 will be described with reference to Fig. 3 to Fig. 6. Fig. 3 is a top view of a plate member 310 included in the busbar module 30, Fig. 4 is a perspective view showing the structure around the busbar in the busbar module, Fig. 5 is a plan view showing the structure of the busbar module before the third busbar 200 is provided, and Fig. 6 is a plan view showing the structure of the busbar module after the third busbar 200 is provided.

[0031] The first busbar module 30A, the second busbar module 30B, and the third busbar module 30C each include a plate member 310 shown in Fig. 3. As shown in Fig. 3, the plate member 310 includes an end face 311 located at the end in the Y-axis direction, an end face 312 located at the end in the X-axis direction, through-holes 313 formed at positions corresponding to the gas release valves 130 of the battery cells 100, and wall portions 314 that divide the space on the plate member 310 into multiple sections.

[0032] As shown in FIG. 4, in the first busbar module 30A, busbars 320 (first busbars) are housed in each space partitioned by the wall portions 314. The busbars 320 (first busbars) are made of a conductor (typically, a metal member). The busbars 320 (first busbars) electrically connect the electrode terminals 110 of the multiple battery cells 100 to one another. The busbars 320 (first busbars) include a root portion 321 extending in the Y-axis direction, and a connection portion 322 (first connection portion) and a connection portion 323 (second connection portion) protruding from the root portion 321 in the X-axis direction. The connection portions 322 and 323 are each connected to the electrode terminals 110 of two battery cells 100 adjacent to each other in the Y-axis direction.

[0033] Bus bar 320 is connected to wiring 410. Wiring 410 is fixed to bus bar 320 (first bus bar) by screws 420. The configuration of wiring 410 and screws 420 is not limited to that shown in Fig. 4, and the wiring may be formed by, for example, a flexible wiring board.

[0034] The electrode terminals 110 of the battery cells 100 and the bus bars 320 (first bus bars) are welded together after being positioned relative to each other in the X-axis and Y-axis directions. By performing this positioning accurately, the welding process between the electrode terminals 110 and the bus bars 320 (first bus bars) can be carried out with high efficiency and high quality.

[0035] 4, in the second busbar module 30B, similarly to the first busbar module 30A, busbars 320 (second busbars) are housed in the respective spaces partitioned by the wall portions 314. The configuration and function of the busbars 320 (second busbars) are the same as those of the busbars 320 (first busbars).

[0036] 4, a third busbar 200 is provided along the X-axis direction so as to bridge the gap between the first busbar module 30A and the second busbar module 30B, and electrically connects one battery cell 100 (first battery cell) selected from the first stack 10A to one battery cell 100 (second battery cell) selected from the second stack 10B. Although not shown in the figure, a third busbar 200 is also provided between the second busbar module 30B and the third busbar module 30C.

[0037] In this embodiment, one battery cell 100 (first battery cell) selected from the first stack 10A is the battery cell located at the end (the extreme end in the Y-axis direction) facing the side wall 21, and one battery cell 100 (second battery cell) selected from the second stack 10B is the battery cell located on the same side (the extreme end in the Y-axis direction and adjacent in the X-axis direction) as the one battery cell 100 (first battery cell) selected from the first stack 10A. Note that the position at which the third bus bar 200 is provided is not limited to the position shown in the figure.

[0038] As shown in Fig. 5, before the third busbar 200 is provided, the negative electrode terminals 112 of the battery cells 100 are exposed on the first busbar module 30A side, and the positive electrode terminals 111 of the battery cells 100 are exposed on the second busbar module 30B side. As shown in Fig. 6, by providing the third busbar 200, the negative electrode terminals 112 on the first busbar module 30A side and the positive electrode terminals 111 of the second busbar module 30B are electrically connected.

[0039] Third bus bar 200 is connected to wiring 410. Wiring 410 is fixed to third bus bar 200 with screws 420. The form of wiring 410 and screws 420 is not limited to that shown in Fig. 4, and the wiring may be formed of, for example, a flexible wiring board.

[0040] The electrode terminals 110 of the battery cells 100 and the third bus bar 200 are welded together after being positioned relative to each other in the X-axis direction and the Y-axis direction. By performing this positioning accurately, the welding process between the electrode terminals 110 and the third bus bar 200 can be carried out with high efficiency and high quality.

[0041] Furthermore, the above-mentioned process of welding busbars 320 (first busbar, second busbar) to electrode terminals 110 and the process of welding third busbar 200 to electrode terminals 110 can be carried out consecutively in the same welding process, making it possible to improve the efficiency of the welding process. Furthermore, third busbar 200 can be manufactured using the same material and with the same thickness as busbars 320 (first busbar, second busbar), thereby reducing the manufacturing cost of third busbar 200.

[0042] Next, the specific shape of third bus bar 200 will be described with reference to Fig. 7. Fig. 7 is a perspective view showing the structure of the third bus bar.

[0043] This third busbar 200 includes a first region 210 that is electrically connected to the battery cell 100 (first battery cell) and located on the first busbar module 30A side, a second region 220 that is electrically connected to the battery cell 100 (second battery cell) and located on the second busbar module 30B side, and a third region 230 that is located at a position that bridges the gap between the first busbar module 30A and the second busbar module 30B and connects the first region 210 and the second region 220.

[0044] Furthermore, when this third busbar 200 is viewed along the Z-axis direction (third direction) perpendicular to the Y-axis direction (first direction) and the X-axis direction (second direction), the third region 230 has a convex shape located above the first region 210 and the second region 220.

[0045] Specifically, the third region 230 has a top surface portion 200a and a pair of first sidewall portions 200b extending downward on both sides of the top surface portion 200a in the X-axis direction.

[0046] The first region 210 has a bottom surface portion 200c, a second side wall portion 200d extending upward from one end of the bottom surface portion 200c, and an extension portion 200e extending parallel to the bottom surface portion 200c from the upper end of the second side wall portion 200d. A circular through-hole 200h1 is provided in the bottom surface portion 200c, and a circular through-hole 200h2 is provided in the extension portion 200e.

[0047] Similar to the first region 210, the second region 220 has a bottom surface 200c, a second side wall 200d extending upward from one end of the bottom surface 200c, and an extension 200e extending parallel to the bottom surface 200c from the upper end of the second side wall 200d. A circular through-hole 200h1 is provided in the bottom surface 200c, and a circular through-hole 200h2 is provided in the extension 200e.

[0048] The through-holes 200h1 are used when welding the electrode terminals 110 of the battery cells 100 to the bottom surface portion 200c. The through-holes 200h2 are used when fastening the wiring 410 using screws 420.

[0049] In the present embodiment, third bus bar 200 has extension portion 200e provided at a height position between bottom surface portion 200c and top surface portion 200a when viewed along the Z-axis direction (third direction).

[0050] The effects of the configuration of third bus bar 200 in this embodiment will now be described with reference to Fig. 8 and Fig. 9. Fig. 8 is a partial enlargement showing a positioning mechanism provided between first laminate 10A and second laminate 10B, and Fig. 9 is a partial enlargement of the vicinity of top surface portion 200a of third bus bar 200.

[0051] In the present embodiment, a positioning mechanism 330 is provided between the first laminate 10A and the second laminate 10B. This positioning mechanism 330 is inserted between two adjacent laminates (between the first laminate 10A and the second laminate 10B in the example of FIG. 8) and has a positioning mechanism 330 for positioning the busbar module 30 in the X-axis direction. In the example of FIG. 8, the first laminate 10A has the positioning mechanism 330A, and the second laminate 10B has the positioning mechanism 330B.

[0052] The positioning mechanism 330 has an insertion portion 331 that is press-fitted between the first laminate 10A and the second laminate 10B. When the insertion portion 331 is press-fitted between the first laminate 10A and the second laminate 10B, the first busbar module 30A is urged in a direction away from the second laminate 10B. At this time, the insertion portion 331 abuts against a side surface of the first laminate 10A, thereby positioning the first busbar module 30A in the X-axis direction. The positioning mechanism 330B has a similar configuration, and when the insertion portion 331 is press-fitted between the first laminate 10A and the second laminate 10B, the second busbar module 30B is urged in a direction away from the first laminate 10A. At this time, the insertion portion 331 abuts against a side surface of the second laminate 10B, thereby positioning the second busbar module 30B in the X-axis direction.

[0053] When the positioning mechanism 330 is provided between the first laminate 10A and the second laminate 10B in this way, it is expected that the end faces 312 of the nearby first busbar module 30A and second busbar module 30B will be higher in the Z-axis direction. In such a case, as shown in Fig. 8, the third region 230 of the third busbar 200 has a convex shape that is located above the first region 210 and the second region 220, which enables the first region 210 to climb over the end face 312 and bridge the gap between the first busbar module 30A and the second busbar module 30B.

[0054] Here, as shown in FIG. 9, if the distance from the bottom surface of the second bus bar module 30B to the lower surface of the top surface portion 200a is set to h1, it is considered that the distance should be approximately 3 mm to 10 mm.

[0055] (Other forms of third busbar) Other embodiments of the third bus bar will be described with reference to Fig. 10 to Fig. 16. Fig. 10 is a perspective view showing a third bus bar 200A in another embodiment, Fig. 11 is a perspective view showing a third bus bar 200B in yet another embodiment, Fig. 12 is a perspective view showing a third bus bar 200C in yet another embodiment, Fig. 13 is a perspective view showing a third bus bar 200D in yet another embodiment, Fig. 14 is a perspective view showing a third bus bar 200E in yet another embodiment, Fig. 15 is a perspective view showing a third bus bar 200F in yet another embodiment, and Fig. 16 is a perspective view showing a third bus bar 200G in yet another embodiment.

[0056] (Third bus bar 200A) Referring to FIG. 10, the third busbar 200A differs from the third busbar 200 shown in FIG. 7 in the shape of the through holes provided in the busbar. Instead of the circular through hole 200h1 provided in the third busbar 200, a rectangular through hole 200h4 with its long side extending in the Y-axis direction is provided in the bottom surface 200c located in the first region 210 of the third busbar 200A. Furthermore, a pair of notched holes 200h5 extending outward along the Y-axis direction are provided on the short sides of the through hole 200h4. The bottom surface 200c located in the second region 220 of the third busbar 200A is provided with only the through hole 200h4. The extension portions 200e of the first region 210 and the second region 220 are provided with a bodhidharma-shaped through hole 200h6 extending at an angle of approximately 45 degrees when viewed in the X-axis and Y-axis directions.

[0057] By making the through-holes in the bottom surface portion 200c rectangular or rectangular with a cutout hole, it is possible to easily position and check the welding when welding the electrode terminals 110 of the battery cells 100 to the bottom surface portion 200c. By making the through-holes in the extension portion 200e shaped like a bodhisattva, the fastening position of the wiring 410 using the screws 420 can slide, which is expected to improve workability.

[0058] (Third bus bar 200B) 11, a major difference between third bus bar 200B and third bus bar 200 shown in FIG. 7 is that third bus bar 200B is made up of two parts. A first plate portion 210P located on the first region 210 side and a second plate portion 220P located on the second region 220 side overlap each other in third region 230. A welded portion WP is provided at this overlapping portion.

[0059] A rectangular through-hole 200h4 and a pair of notched holes 200h5 are provided in the bottom surface portion 200c located in the first region 210. Only the through-hole 200h4 is provided in the bottom surface portion 200c located in the second region 220. A circular through-hole 200h6 is provided in the extending portions 200e of the first region 210 and the second region 220. By configuring the third bus bar 200B from two parts, it is possible to absorb dimensional tolerances.

[0060] (Third bus bar 200C) 12, the major difference between third busbar 200C and third busbar 200B shown in FIG. 11 is that third busbar 200C is also composed of two parts, and in the third region 230, first plate portion 210P is provided with a first extension portion 210a extending in the Y-axis direction, and second plate portion 220P is also provided with a second extension portion 220a extending in the Y-axis direction. This allows the overlapping region between first plate portion 210P and second plate portion 220P to be expanded in third region 230, and welded portions WP are provided at the overlapping portions of first extension portion 210a and second extension portion 220a. This configuration allows the path length of the busbar to be increased.

[0061] (Third bus bar 200D) 13, a major difference between third bus bar 200D and third bus bar 200B shown in Fig. 11 is that third bus bar 200D is also made up of two parts, and first plate portion 210P and second plate portion 220P are fastened together in third region 230 using bolt B1 rather than welding. This configuration is also expected to provide the same effects as third bus bar 200B.

[0062] (Third bus bar 200E) 14, a major difference between third busbar 200E and the third busbar 200 shown in FIG. 7 is the shape of the through holes provided in the first region 210 and the second region 220. The through holes provided in the first region 210 and the second region 220 of third busbar 200E include a first thin-walled portion 230h1 that is elliptical and has its major axis aligned in the Y-axis direction, a rectangular through hole 230h2 that is provided in this first thin-walled portion 230h1 and has its long side aligned in the Y-axis direction, and a circular through hole 230h3 that is provided so as to overlap the center of through hole 230h2. Even with this configuration, it is expected that the same effects as those of third busbar 200 can be obtained.

[0063] (3rd bus bar 200F) 15, a major difference between third busbar 200F and the third busbar 200 shown in FIG. 7 is the shape of the through holes provided in first region 210 and second region 220. The through holes provided in first region 210 and second region 220 of third busbar 200F include a rectangular thin-walled portion 240h1 with its long side aligned in the Y-axis direction, a rectangular through hole 240h2 provided in this thin-walled portion 240h1 with its long side aligned in the Y-axis direction, and a notched hole 240h3 extending from the center of through hole 240h2 in the X-axis direction. This configuration is also expected to provide the same effects as those of third busbar 200.

[0064] (3rd bus bar 200G) 16, a major difference between third busbar 200G and the third busbar 200 shown in FIG. 7 is the shape of the through holes provided in first region 210 and second region 220. The through holes provided in first region 210 and second region 220 of third busbar 200F include a square-shaped thin-walled portion 250h1, a circular through hole 250h2 provided in this thin-walled portion 250h1 and offset in the Y-axis direction, and a notch 250h3 extending in the X-axis direction at a position offset in the Y-axis direction from the center of through hole 250h2. Even with this configuration, it is expected that the same effects as those of third busbar 200 can be obtained.

[0065] The third bus bar may be formed by appropriately combining the bus bar, the thin portion, and the hole.

[0066] Although the embodiments of the present technology have been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present technology is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0067] 1 battery pack, 10 laminate, 10A first laminate, 10B second laminate, 10C third laminate, 20 case, 21 side wall, 30 bus bar module, 30A first bus bar module, 30B second bus bar module, 30C third bus bar module, 100 battery cell, 110 electrode terminal, 111 positive terminal, 112 negative terminal, 120 housing, 121 upper surface, 122 lower surface, 123 first side surface, 124 second side surface, 125 third side surface, 130 gas release valve, 200, 200A, 200B, 200C, 200D, 200E, 200F, 200G third bus bar, 200a top surface portion, 200b first side wall portion, 200c bottom surface portion, 200d second side wall portion, 200e Extension portion, 200h1, 200h2, 200h4, 200h6, 230h2, 230h3, 240h2, 250h2, 313 Through hole, 200h5, 240h3, 250h3 Notch hole, 210 First region, 210P First plate portion, 210a First extension portion, 220 Second region, 220P Second plate portion, 220a Second extension portion, 230 Third region, 230h1 First thin portion, 240h1, 250h1 Thin portion, 310 Plate member, 311, 312 End face, 314 Wall portion, 320 Bus bar, 321 Base portion, 322, 323 Connection portion, 330, 330A, 330B Positioning mechanism, 331 Insertion portion, 410 Wiring, 420 screws.

Claims

1. a first stack including a plurality of first battery cells arranged in a first direction; a second stack adjacent to the first stack in a second direction perpendicular to the first direction and including a plurality of second battery cells aligned in the first direction; a case having side walls facing the first stack and the second stack in the first direction, the case housing the first stack and the second stack; a first bus bar that electrically connects the plurality of first battery cells, and a first bus bar module that houses the first bus bar and is disposed on the first stack; a second bus bar that electrically connects the plurality of second battery cells, and a second bus bar module that houses the second bus bar and is disposed on the second stack; a third bus bar that is provided along the second direction so as to bridge between the first bus bar module and the second bus bar module, and that electrically connects one of the first battery cells selected from the first stack and one of the second battery cells selected from the second stack; and Equipped with The third bus bar is a first region electrically connected to the first battery cell and located on the first bus bar module side; a second region electrically connected to the second battery cell and located on the second bus bar module side; a third region provided at a position bridging the gap between the first bus bar module and the second bus bar module, the third region communicating with the first region and the second region, When viewed along a third direction orthogonal to the first direction and the second direction, the third region has a convex shape located above the first region and the second region, the third region has a convex shape formed by a top surface portion and a pair of first sidewall portions extending downward on both sides of the top surface portion, The first region and the second region each have a bottom surface portion that is continuous with the lower end side of the first side wall portion and is located below the top surface portion, a second side wall portion that extends upward from one end of the bottom surface portion opposite the first side wall portion, and an extension portion that extends from the upper end of the second side wall portion in parallel to the bottom surface portion and is located below the top surface portion. Battery pack.

2. The first battery cell selected from the first stack is located at the end facing the side wall, The second battery cell selected from the second stack is located on the same side as the first battery cell selected from the first stack. The battery pack according to claim 1 .

3. a positioning mechanism inserted between the first stack and the second stack and configured to position the first stack and the second stack in an X-axis direction; The third region is located above the positioning mechanism. The battery pack according to claim 1 .

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