Battery pack

Abstract

The invention relates to a battery pack. The plate member (310) has a wall section (314) that defines a space for respectively providing a plurality of bus bars (320) adjacent to each other in the stacking direction (first direction) of the battery cells (100), and the wall section (314) has a first portion (314A) and a second portion (314B) that extend in a second direction orthogonal to the first direction, and a third portion (314C) that connects the first portion (314A) and the second portion (314B). The first portion (314A) and the second portion (314B) are located at positions separated from each other in the first direction, the third portion (314C) extends in the first direction, and the wall portion (314) further includes ribs (315) that protrude from the wall portion (314) toward both sides in the first direction and position a plurality of bus bars (320) adjacent to each other in the first direction.

Description

Technical Field

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

[0002] The specification of Chinese Patent Application Publication No. 115189104 shows a battery connection module (bus bar module) in which a plurality of busbars are accommodated in a carrier. Summary of the invention

[0003] When connecting the electrode terminals of the battery cells to the bus bars, it is preferable to accurately position the battery cells and the bus bars relative to each other. Therefore, in the bus bar module, it is preferable to accurately position the bus bars accommodated in the plate member.

[0004] An object of the present invention is to provide a battery pack capable of accurately positioning bus bars in a bus bar module.

[0005] The present invention provides the following battery pack.

[0006] [1] A battery pack, wherein the battery pack comprises: a stack including a plurality of battery cells arranged in a first direction; a housing for housing the stack; and a busbar module, which is arranged on the stack and includes a busbar for electrically connecting the plurality of battery cells and a plate member for housing the busbar, the plate member having a wall portion for dividing a space for respectively arranging a plurality of busbars adjacent to each other in the first direction, the wall portion having a first portion and a second portion extending in a second direction orthogonal to the first direction and a third portion connecting the first portion and the second portion, the first portion and the second portion being located at positions separated from each other in the first direction, the third portion extending in the first direction, and the wall portion further including ribs protruding from the wall portion to both sides in the first direction and for positioning the plurality of adjacent busbars in the first direction.

[0007] [2] In the battery pack described in [1], the rib is located adjacent to the third portion.

[0008] [3] In the battery pack described in [1] or [2], the wall portion further includes a mechanism for locking the bus bar from a third direction orthogonal to the first direction and the second direction.

[0009] [4] In the battery pack described in any one of [1] to [3], the busbar includes: a root portion extending in a first direction; and a first connecting portion and a second connecting portion protruding from the root portion in a second direction and electrically connected to a plurality of battery cells, respectively, and the rib is located at a position abutting against both sides of the root portion in the first direction, the first connecting portion, and the second connecting portion.

[0010] The above and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is an exploded perspective view of the battery pack.

[0012] Figure 2 It is a three-dimensional diagram of a battery cell.

[0013] Figure 3 It is a top view of the plate component in the busbar module.

[0014] Figure 4 It is a perspective view showing the structure around the busbar.

[0015] Figure 5 It is a diagram showing a positioning mechanism of the busbar module in the Y-axis direction.

[0016] Figure 6 It is a perspective view showing the structure between the bus bar module and the upper surface of the battery cell.

[0017] Figure 7 It is a perspective view showing the back side of a plate member in a busbar module.

[0018] Figure 8 It is a diagram showing a positioning mechanism of the busbar module in the X-axis direction.

[0019] Fig. 9 It means to observe from above Figure 4 A diagram showing the state of the construction.

[0020] Fig.10 yes Fig. 9 The X-X section view in.

[0021] Fig.11 yes Fig. 9 XI-XI section view in the figure. DETAILED DESCRIPTION

[0022] Hereinafter, an embodiment of the present invention will be described. In addition, the same reference numerals may be given to the same or corresponding parts, and the description thereof may not be repeated.

[0023] In addition, in the embodiments described below, when the number, quantity, etc. are mentioned, except for the cases specifically described, the scope of the present invention is not necessarily limited to the number, quantity, etc. In addition, in the following embodiments, each component is not necessarily essential to the present invention except for the cases specifically described. In addition, the present invention is not necessarily limited to achieving all the effects mentioned in the present embodiments.

[0024] In addition, in this specification, the descriptions of “comprise”, “include”, and “have” are open-ended. That is, when a certain structure is included, other structures other than the structure may be included or other structures other than the structure may not be included.

[0025] In addition, in this specification, when geometric terms and terms indicating position and direction relationships, such as "parallel", "orthogonal", "oblique 45°", "coaxial", "along", etc., are used, these terms allow for manufacturing errors or slight changes. In this specification, when terms such as "upper side" and "lower side" are used to indicate relative positional relationships, these terms are used to indicate relative positional relationships in one state, and the relative positional relationship can be flipped or rotated to any angle by the setting direction of each mechanism (for example, turning the entire mechanism upside down, etc.).

[0026] In this specification, "battery" is not limited to lithium-ion batteries, and can include other batteries such as nickel-metal hydride batteries and sodium-ion batteries. In this specification, "battery pack" can be installed in hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV) and electric vehicles (BEV). However, the use of "battery cells" is not limited to vehicle use.

[0027] Figure 1 1 is an exploded perspective view of the battery pack 1. Figure 1 As shown, the battery pack 1 includes: a plurality of battery cells 100 (see Figure 2 ) of a stacked body 10; a housing 20 for housing the stacked body 10; and a busbar module 30 disposed on the stacked body 10.

[0028] The stack 10 includes a stack 10A (first stack), a stack 10B (second stack), and a stack 10C (third stack). The stacks 10A and 10B are adjacent to each other in the X-axis direction (second direction). The stacks 10B and 10C are adjacent to each other in the X-axis direction.

[0029] The housing 20 has side walls 21 facing the stacked bodies 10A, 10B, and 10C in the Y-axis direction. The side walls 21 directly support the stacked bodies 10A, 10B, and 10C from both sides in the Y-axis direction. In this way, the battery pack 1 of this embodiment is a battery pack adopting a Cell-to-Pack structure in which the stacked body 10 including a plurality of battery cells 100 is directly accommodated in the housing.

[0030] The busbar module 30 includes a busbar module 30A (first busbar module) disposed on the stack 10A, a busbar module 30B (second busbar module) disposed on the stack 10B, and a busbar module 30C (third busbar module) disposed on the stack 10C.

[0031] Figure 2 1 is a perspective view showing the structure of a battery cell 100 constituting the stacked bodies 10A, 10B, and 10C. Figure 2 As shown, the battery cell 100 has a square shape and includes an electrode terminal 110 , a frame 120 , and a gas exhaust valve 130 .

[0032] The electrode terminal 110 is formed on the frame 120. The electrode terminal 110 includes a positive terminal 111 and a negative terminal 112 as two electrode terminals 110 arranged along the X-axis direction (second direction) orthogonal to the Y-axis direction (first direction). The positive terminal 111 and the negative terminal 112 are provided to be separated from each other in the X-axis direction.

[0033] The frame 120 has a substantially rectangular parallelepiped shape. An electrode assembly and an electrolyte solution (not shown) are accommodated in the frame 120. The frame 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.

[0034] The upper surface 121 is a plane perpendicular to the Z-axis direction. The electrode terminal 110 is arranged 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).

[0035] Each of the first side surface 123 and the second side surface 124 is formed of a plane orthogonal 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 frame body 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 in which the X-axis direction is the long side direction and the Z-axis direction is the short side direction when viewed in the Y-axis direction.

[0036] The plurality of battery cells 100 are stacked such that the first side surfaces 123 and the second side surfaces 124 face each other between the battery cells 100 and 100 adjacent to each other in the Y-axis direction. Thus, the positive terminals 111 and the negative terminals 112 are alternately arranged in the Y-axis direction.

[0037] The gas discharge valve 130 is provided on the upper surface 121 . When the internal pressure of the housing 120 increases to a predetermined value or more due to the gas generated inside the housing 120 , the gas discharge valve 130 opens and discharges the gas to the outside of the housing 120 .

[0038] Next, use Figure 3 and Figure 4 , the basic structure of the busbar module 30 is described. Figure 3 3 is a top view of the plate member 310 included in the busbar module 30 . Figure 4 It is a perspective view showing the structure around the bus bar 320 in the bus bar module 30 .

[0039] The busbar modules 30A, 30B, and 30C respectively include Figure 3 The plate member 310 is shown. Figure 3 As shown, 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; a through hole 313 formed at a position corresponding to the gas exhaust valve 130 of the battery cell 100; and a wall portion 314 that divides the space on the plate member 310 into multiple parts.

[0040] like Figure 4 As shown, busbars 320 are housed in each space separated by the wall portion 314. The busbar 320 is composed of a conductor (typically a metal member). The busbar 320 electrically connects the electrode terminals 110 of multiple battery cells 100 to each other. The busbar 320 includes a root portion 321 extending in the Y-axis direction and a connecting portion 322 (first connecting portion) and a connecting portion 323 (second connecting portion) protruding from the root portion 321 in the X-axis direction. The connecting portions 322 and 323 are respectively connected to the electrode terminals 110 of two battery cells 100 adjacent to each other in the Y-axis direction.

[0041] The wall portion 314 of the plate member 310 includes a first portion 314A, a second portion 314B, and a third portion 314C. The first portion 314A and the second portion 314B are formed to extend in the X-axis direction. The first portion 314A and the second portion 314B are located at mutually separated positions in the Y-axis direction. The third portion 314C connects the first portion 314A and the second portion 314B.

[0042] The wall portion 314 is formed with a rib 315 and a locking portion 316. The rib 315 protrudes from a position adjacent to the third portion 314C of the wall portion 314 to both sides in the Y-axis direction. The rib 315 positions the adjacent plurality of busbars 320 in the Y-axis direction. The locking portion 316 locks the busbar 320 in the Z-axis direction. The shape or arrangement of the rib 315 and the locking portion 316 is not limited to Figure 4 The structure shown can be modified appropriately.

[0043] The busbar 320 is connected to the wiring 410. The wiring 410 is fixed to the busbar 320 by screws 420. The wiring 410 and the screws 420 are not limited to Figure 4 In the structure shown, for example, wiring can be formed by a flexible wiring substrate.

[0044] The electrode terminal 110 of the battery cell 100 and the bus bar 320 are positioned relative to each other in the X-axis direction and the Y-axis direction and then welded together. By accurately performing this positioning, the welding process of the electrode terminal 110 and the bus bar 320 can be carried out efficiently and with high quality. Therefore, when the bus bar 320 is stored in the space separated by the wall portion 314, it is preferred that the bus bar 320 is accurately positioned relative to the plate member 310. In addition, it is preferred that the positioning of the plate member 310 and the stacked body 10 is also performed with high precision.

[0045] use Figures 5 to 8 , a positioning mechanism of the bus bar module 30 (plate member 310) in this embodiment will be described.

[0046] Figure 5 2 is a diagram showing the positioning mechanism of the busbar module 30 in the Y-axis direction. Figure 5 As shown, the plate member 310 of the bus bar module 30 has a positioning mechanism 317 for positioning the bus bar module 30 in the Y-axis direction by applying force to the side wall 21 of the housing 20 .

[0047] Figure 5 The positioning mechanism 317 shown is composed of a snap-fit ​​shaped protrusion formed on the end surface 311 of the plate member 310. The protrusion constituting the positioning mechanism 317 protrudes from the end surface 311 of the plate member 310 toward the side wall 21. When the plate member 310 is set in the housing 20, the positioning mechanism 317 presses the side wall 21 of the housing 20 to force the plate member 310 toward a predetermined position. As a result, the busbar module 30 is positioned in the Y-axis direction.

[0048] The positioning mechanism 317 may be provided on the end faces 311 on both sides of the plate member 310 in the Y-axis direction, or may be provided only on the end face 311 on one side of the plate member 310 in the Y-axis direction. In the case where the positioning mechanism 317 is provided on both sides in the Y-axis direction, the plate member 310 is forced toward the center of the housing 20 in the Y-axis direction, and is positioned at a position where the forces applied by the positioning mechanisms 317 on both sides are balanced. In the case where the positioning mechanism 317 is provided on one side in the Y-axis direction, the plate member 310 is forced toward the side wall 21 on the opposite side of the side where the positioning mechanism 317 is provided, and is positioned with the side wall 21 as a reference surface.

[0049] As a reaction to the side wall 21 of the pressing case 20, the protrusion constituting the positioning mechanism 317 is deformed toward the center side of the stacked body 10. At this time, the positioning mechanism 317 is preferably located at a position that does not interfere with the gas discharge valve 130 when viewed from the Z-axis direction. By setting it in this way, the busbar module 30 can be positioned in the Y-axis direction without affecting the gas discharge from the gas discharge valve 130 of the battery cell 100 located at the end in the Y-axis direction.

[0050] Figure 6 It is a perspective view showing the structure between the bus bar module 30 and the upper surface 121 of the battery cell 100 .

[0051] like Figure 6 As shown, the stack 10 includes a spacer 11 disposed between a plurality of battery cells 100. The spacer 11 may be a film or a tape covering the first side 123, the second side 124, and the third side 125 of the battery cell 100. The spacer 11 may also be a film covering the frame 120. The spacer 11 may also be a plate-like member (plate) sandwiched between adjacent battery cells 100. The spacer 11 may also be formed by combining the above-mentioned film or tape with a plate-like member. The spacer 11 has a protrusion 11A protruding toward the plate member 310 side than the plurality of battery cells 100. The plate member 310 has a recess 318 avoiding the protrusion 11A of the spacer 11.

[0052] Figure 7 3 is a perspective view showing the back side of the plate member 310. Figure 7 As shown, the plate member 310 has a bottom surface 319A. The bottom surface 319A faces the upper surface of the battery cell 100. A protruding rib 319 protruding from the bottom surface 319A of the plate member 310 toward the upper surface 121 of the battery cell 100 is provided on a portion of the bottom surface 319A of the plate member 310. The protruding rib 319 abuts against the upper surface 121 of the battery cell 100. Figure 7 In the example of FIG. 3 , the protruding ribs 319 are intermittently formed on both sides of the through hole 313 so as to extend in the Y-axis direction.

[0053] Figure 8 2 is a diagram showing the positioning mechanism of the busbar module 30 in the X-axis direction. Figure 8 As shown, the busbar module 30 has two adjacent stacked bodies (in Figure 8 In the example of FIG. 1 , the positioning mechanism 330 is provided between the stacked bodies 10A and 10B and performs positioning of the busbar module 30 in the X-axis direction. Figure 8 In the example, the busbar module 30A has a positioning mechanism 330A, and the busbar module 30B has a positioning mechanism 330B, but the scope of the present invention is not limited to all busbar modules 30 having a positioning mechanism 330, and only a part of the multiple busbar modules 30 may have a positioning mechanism 330.

[0054] The positioning mechanism 330A has an insertion portion 331A that is pressed between the stacked bodies 10A and 10B. When the insertion portion 331A is pressed between the stacked bodies 10A and 10B, the busbar module 30A is forced in a direction away from the stacked body 10B. At this time, the insertion portion 331A abuts against the side surface of the stacked body 10A, thereby positioning the busbar module 30A in the X-axis direction.

[0055] The positioning mechanism 330B has an insertion portion 331B that is pressed between the stacked bodies 10A and 10B. When the insertion portion 331B is pressed between the stacked bodies 10A and 10B, the busbar module 30B is forced in a direction away from the stacked body 10A. At this time, the insertion portion 331B abuts against the side surface of the stacked body 10B, thereby positioning the busbar module 30B in the X-axis direction.

[0056] Next, use Figures 9 to 11 , the positioning of the busbar 320 relative to the plate member 310 is described in more detail. Fig. 9 It means to observe from above Figure 4 The diagram of the state of the structure shown, Fig.10 , Fig.11 yes Fig. 9 The X-X section view and XI-XI section view in it.

[0057] exist Fig. 9 In the illustrated example, the ribs 315 are provided at four locations and the locking portions 316 are provided at three locations in a substantially rectangular space partitioned by the wall portion 314 .

[0058] More specifically, the ribs 315 are provided at two locations on both sides of the root 321 of the busbar 320 and at one location each to abut against the connection portions 322 and 323. The locking portion 316 is provided at one side of the root 321 of the busbar 320 and at one location each to abut against the connection portions 322 and 323.

[0059] However, in the case of providing a flexible substrate to replace Fig. 9 In the case of the wiring 410 shown, the screws 420 can be omitted, so it is also possible to add the locking portion 316 near the screw 420 and provide four locking portions 316 for one bus bar 320 .

[0060] The first part 314A, the second part 314B and the third part 314C of the wall part 314 form a crank shape. The rib 315 is formed to protrude from a position adjacent to the third part 314C forming the crank shape toward both sides in the Y-axis direction. The locking part 316 is formed at a position separated from the third part 314C and the rib 315 in the X-axis direction.

[0061] like Fig.10As shown, the rib 315 positions the busbar 320 in the Y-axis direction by contacting the busbar 320 from the side (Y-axis direction). When the busbar 320 is accommodated in the plate member 310, the busbar 320 is moved downward along the inclined surface 315A provided above the rib 315. From the viewpoint of improving the positioning accuracy of the busbar 320, the gap (tolerance) between the rib 315 and the busbar 320 is preferably as small as possible.

[0062] like Fig.11 As shown, the locking portion 316 locks the busbar 320 in the Z-axis direction by contacting the busbar 320 from above (in the Z-axis direction). When the busbar 320 is accommodated in the plate member 310, the busbar 320 is moved downward along the inclined surface 316A provided above the locking portion 316. At this time, the wall portion 314 is deformed in a flexural manner, so that the busbar 320 can be pushed downward over the protruding portion of the locking portion 316.

[0063] When a wall portion is provided at a position corresponding to the middle between the first portion 314A and the second portion 314B of the wall portion 314 and the rib 315 and the locking portion 316 protrude from this position, it is necessary to increase the protrusion amount of the rib 315 and the locking portion 316 from the wall portion 314. Figures 9 to 11 Compared with the structure shown, it is necessary to extend the inclined surfaces 315A and 316A or increase the inclination relative to the vertical direction (make the inclination of the inclined surfaces 315A and 316A close to the horizontal direction). As a result, it is difficult to smoothly push the bus bar 320 downward toward the battery cell 100.

[0064] On the other hand, when a pair of wall portions are provided at positions corresponding to the first portion 314A and the second portion 314B of the wall portion 314, respectively, and the rib 315 and the locking portion 316 protrude from the respective positions, it is possible to provide Figures 9 to 11 The structure shown in the figure has the same shape of rib 315 and locking portion 316. However, a narrow gap needs to be provided between the pair of wall portions, and it is difficult to form the plate member 310 by resin molding. In addition, even if resin molding is possible, the pair of wall portions are formed at positions close to each other in the Y-axis direction. Therefore, in the process of pushing the busbar 320, when one wall portion is bent near the locking portion 316, it is possible to interfere with the other wall portion.

[0065] In addition, when the pair of wall portions are integrated, the wall portion 314 is formed thick, which may impair the flexibility of the wall portion 314 (near the locking portion 316) required for pushing in the bus bar 320. In addition, it may hinder the weight reduction of the plate member 310 and the reduction of the manufacturing cost.

[0066] In the busbar module 30 of the present embodiment, the wall portion 314 of the plate member 310 has a crank shape, and the ribs 315 protrude from the first portion 314A and the second portion 314B close to the busbar 320 in the Y-axis direction toward the busbar 320. Therefore, while the wall portion 314 is not made too thick and the protruding height of the ribs 315 is reduced, the gap between the ribs 315 and the busbar 320 in the Y-axis direction can be reduced, thereby improving the positioning accuracy of the busbar 320.

[0067] The battery pack 1 adopts a cell-to-pack structure in which the stacked body 10 including a plurality of battery cells 100 is directly housed in the case 20 . Therefore, members such as restraint bars in the module structure cannot be used as members for positioning the bus bar module 30 .

[0068] In the battery pack 1 of this embodiment, the busbar module 30 can be positioned in the Y-axis direction by applying force to the side wall 21 of the shell 20 through the positioning mechanism 317 provided on the plate member 310. Therefore, in the battery pack 1 with a Cell-to-Pack structure, the busbar module 30 can be positioned with high precision without providing a complex mechanism.

[0069] In the battery pack 1, the protruding rib 319 protruding from the bottom surface 319A of the plate member 310 toward the battery cell 100 abuts against the upper surface 121 of the battery cell 100. In this way, by making the protruding rib 319 abut against the battery cell 100, the contact area between the plate member 310 and the upper surface 121 of the battery cell 100 can be reduced, and the friction resistance when the plate member 310 moves relative to the battery cell 100 can be reduced, so that the plate member 310 can be positioned smoothly and accurately.

[0070] In addition, the shape and arrangement of the protruding rib 319 are not limited to Figure 7 In addition, in the present invention, the protruding rib 319 is not necessarily a necessary structure.

[0071] In the battery pack 1, the plate member 310 has the recessed portion 318 avoiding the protruding portion 11A of the spacer 11. Therefore, when the plate member 310 is positioned in the Y-axis direction by the positioning mechanism 317, the movement of the plate member 310 in the Y-axis direction is not hindered by the protruding portion 11A of the spacer 11. Therefore, the plate member 310 can be positioned smoothly and accurately.

[0072] However, in the present invention, the protrusion 11A of the spacer 11 and the recess 318 of the plate member 310 are not necessarily essential structures.

[0073] The battery pack 1 is provided with a positioning mechanism 330 inserted between the stacked bodies 10A and 10B to position the bus bar modules 30A and 30B in the X-axis direction. Therefore, the plate member 310 can be positioned in the X-axis direction in addition to the Y-axis direction.

[0074] However, in the present invention, the X-axis direction positioning mechanism 330 is not necessarily a necessary structure. In addition, all of the plurality of busbar modules 30A, 30B, 30C may be equipped with the positioning mechanism 330, or a part of the plurality of busbar modules 30A, 30B, 30C may be equipped with the positioning mechanism 330.

[0075] According to the present invention, a battery pack can be provided that can accurately position the busbars in the busbar module by providing ribs on the busbar module for positioning the busbars in the stacking direction (first direction) of the battery cells. Here, by making the wall portion have a crank shape including the first part to the third part, the positioning accuracy of the busbar can be improved while suppressing the reduction in the workability when pushing the busbar.

[0076] Although the embodiments of the present invention have been described, the embodiments disclosed this time should be considered to be illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims, and it is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A battery pack, wherein: The battery pack has: a stack including a plurality of battery cells arranged in a first direction; a housing that accommodates the stacked body; and a busbar module disposed on the stacked body, comprising a busbar for electrically connecting the plurality of battery cells and a plate member for accommodating the busbar; The plate member has a wall portion that partitions spaces for arranging a plurality of the busbars adjacent to each other in the first direction. The wall portion includes a first portion and a second portion extending in a second direction orthogonal to the first direction, and a third portion connecting the first portion and the second portion, the first portion and the second portion being located at positions separated from each other in the first direction, and the third portion extending in the first direction. The wall portion further includes ribs that protrude from the wall portion toward both sides in the first direction and that position a plurality of adjacent busbars in the first direction.

2. The battery pack according to claim 1, wherein: The rib is located adjacent to the third portion.

3. The battery pack according to claim 1 or 2, wherein: The wall portion further includes a mechanism for locking the busbar from a third direction orthogonal to the first direction and the second direction.

4. The battery pack according to claim 1 or 2, wherein: The bus bar includes: a root portion extending in the first direction; and a first connecting portion and a second connecting portion protruding from the root portion toward the second direction and electrically connected to the plurality of battery cells, respectively. The rib is located at a position abutting against both sides of the root portion in the first direction, the first connecting portion, and the second connecting portion.

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