Battery module

Abstract

To provide a battery module which has a space-saving configuration for connecting battery cells to each other, and which can be manufactured at a low cost.SOLUTION: In a battery module 20, a plurality of battery cells 1 of a battery stack 11 are laminated in such a manner that one of positive and negative cell terminals 6, 7 is aligned in a lamination direction at one end Y1 side in a width direction, while the other one of the cell terminals, which is different from the former one, is aligned in the lamination direction at the other end Y2 side opposite to the one end Y1 in the width direction. The battery module 20 has: an adjacent connection bus bar 31 which connects cell terminals 6, 7 adjacent in the lamination direction; and a jumper connection bus bar 35 which connects cell terminals 6, 7 aligned on both sides, in the lamination direction, of the cell terminals 6, 7 connected by the adjacent connection bus bar 31. The positions, in the width direction, of connection points between the cell terminals 6, 7 and a bus bar 30 are aligned in the lamination direction at the one end Y1 side and the other end Y2 side in the width direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosed technology relates to a battery module including a battery stack formed by stacking a plurality of battery cells, and bus bars that connect cell terminals of the battery cells to each other. [Background technology]

[0002] Some battery modules are configured by stacking a plurality of battery cells to form a battery stack, and electrically connecting the battery cells in the battery stack with a bus bar. For example, Patent Document 1 discloses a battery module in which the cell terminals of the plurality of battery cells that constitute the battery stack are connected to each other by a jumper connection bus bar, among the plurality of cell terminals that are arranged in the stacking direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-047583 A Summary of the Invention [Problem to be solved by the invention]

[0004] The jumper connection busbar according to the above-mentioned conventional technology has a shape that makes a detour around a cell terminal located between two connected cell terminals in the width direction perpendicular to the stacking direction of the battery cells. Also, for each cell terminal arranged in the stacking direction, jumper connection busbars that make a detour to the outside in the width direction and jumper connection busbars that make a detour to the inside in the width direction are arranged alternately. The jumper connection busbars that make a detour to the outside in the width direction are connected to an outer position in the width direction of the upper surface of the cell terminal. On the other hand, the jumper connection busbars that make a detour to the inside in the width direction are connected to an inner position in the width direction of the upper surface of the cell terminal.

[0005] For this reason, battery modules according to the prior art use cell terminals that are large in width. In other words, the cell terminals that connect the battery cells together are large. In battery cells using such cell terminals, the space for providing other components tends to be insufficient.

[0006] In addition, in the battery module according to the conventional technology, the connection positions between the jumper connection busbars that are detouring outward in the width direction and the cell terminals are shifted in the width direction from the connection positions between the jumper connection busbars that are detouring inward in the width direction and the cell terminals. Therefore, the connection positions between the cell terminals and the busbars arranged in the stacking direction are provided in a meandering manner in the width direction. Therefore, the equipment for connecting the cell terminals and the busbars tends to be complicated and expensive.

[0007] The present disclosure provides a battery module that has a space-saving configuration for connecting battery cells together and that can be manufactured inexpensively. [Means for solving the problem]

[0008] One aspect of the disclosed technique is a battery module including a battery stack formed by stacking a plurality of flat-shaped battery cells, and a bus bar that connects cell terminals of the battery cells together, the plurality of battery cells being electrically connected in series by the bus bar, the plurality of battery cells of the battery stack being stacked with their terminal outer faces, which are outer faces on which both positive and negative cell terminals are provided, facing in the same direction, and one of the positive and negative cell terminals is stacked on the terminal outer face while being aligned in the stacking direction, with one of the positive and negative cell terminals on one end side in a width direction that intersects with the stacking direction of the battery cells, and the other cell terminal, different from the one cell terminal, on the other end side opposite to the one end side in the width direction. The battery module has busbars including an adjacent connection busbar that connects adjacent cell terminals in the stacking direction, and a jumper connection busbar that connects cell terminals arranged on either side in the stacking direction of two cell terminals connected by the adjacent connection busbar, the jumper connection busbar has a detour shape that detours in the width direction around the adjacent connection busbar and the cell terminal located between the two cell terminals connected by the jumper connection busbar, and the widthwise positions of the connection points between the cell terminals and the busbars are aligned in the stacking direction at each of one end side and the other end side in the width direction.

[0009] In the battery module according to the above aspect, the connection points between the cell terminals and the bus bars are aligned in the stacking direction. Therefore, the cell terminals can be small. In addition, because the connection points between the cell terminals and the bus bars are aligned in the stacking direction, the equipment for connecting these can be simple in structure. Therefore, the battery module according to the above aspect has a space-saving configuration for connecting the battery cells, and can be manufactured inexpensively. Effect of the Invention

[0010] According to the disclosed technique, a battery module is provided in which the configuration for connecting battery cells saves space and can be manufactured inexpensively. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is an external perspective view of a battery cell according to the embodiment. [Diagram 2] FIG. 2 is a plan view of a battery module according to the embodiment. [Diagram 3] FIG. 2 is a cross-sectional view of a battery module according to an embodiment. [Figure 4] 4 is a plan view of a battery module according to a first comparative example different from the embodiment. FIG. [Diagram 5] 11 is a plan view of a battery module according to a second comparative example different from the embodiment. FIG. [Figure 6] FIG. 11 is a plan view of a battery module according to a third comparative example different from the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. First, a battery cell constituting a battery module according to this embodiment will be described. As shown in FIG. 1, the battery cell 1 is generally configured by housing an electrode assembly 3 inside an exterior body 2. The electrode assembly 3 is configured by stacking a positive electrode plate 3A and a negative electrode plate 3B with a separator 3C sandwiched between them. The electrode assembly 3 may be configured by stacking the positive electrode plate 3A, the negative electrode plate 3B, and the separator 3C, for example, by flat stacking, or by winding. The exterior body 2 is configured by a box body 4 and a lid body 10. An electrolyte 5 is contained inside the exterior body 2.

[0013] Fig. 1 shows the X direction, Y direction, and Z direction. The battery cells 1 are arranged so that their thickness direction is in the X direction, their width direction is in the Y direction, and their height direction is in the Z direction. As shown in Fig. 1, the exterior body 2 has a flat shape. Specifically, the exterior body 2 of this embodiment has a rectangular parallelepiped shape.

[0014] A positive cell terminal 6 and a negative cell terminal 7 are provided near both ends in the width direction of the lid 10 on the top of the battery cell 1. The cell terminals 6, 7 are each attached to the lid 10 via an insulating material. Both cell terminals 6, 7 are provided so as to be exposed on the outer surface 12 of the lid 10, which is part of the outer surface of the exterior body 2 of the battery cell 1. The positive cell terminal 6 and the negative cell terminal 7 are each electrically connected inside the exterior body 2 to the positive electrode plate 3A and the negative electrode plate 3B that constitute the electrode body 3.

[0015] When the battery cell 1 is viewed from the outside, the positive cell terminal surface 6A of the positive cell terminal 6 and the negative cell terminal surface 7A of the negative cell terminal 7 are visible. The positive cell terminal surface 6A and the negative cell terminal surface 7A are surfaces to which bus bars and the like that form a current path for charging and discharging the battery cell 1 are connected. This allows the battery cell 1 to be charged or discharged via the positive cell terminal 6 and the negative cell terminal 7.

[0016] The lid 10 of the battery cell 1 is provided with a gas exhaust port 8. The gas exhaust port 8 is a portion that exhausts gas inside the exterior body 2 to the outside when the internal pressure of the exterior body 2 rises beyond a limit. This keeps the internal pressure of the exterior body 2 within an appropriate range. In the battery cell 1 of this embodiment, the gas exhaust port 8 is provided near the center of the lid body 10. That is, the gas exhaust port 8 is provided in a location between the positive electrode cell terminal 6 and the negative electrode cell terminal 7 of the lid body 10.

[0017] FIG. 2 shows a plan view of a battery module 20. The battery module 20 has a battery stack 11 and a bus bar 30. The battery stack 11 is configured by stacking a plurality of battery cells 1 in the thickness direction. An insulating spacer may be sandwiched between adjacent battery cells 1 in the battery stack 11. In this embodiment, the plurality of battery cells 1 constituting the battery stack 11 all have the same shape. In FIG. 2, the battery stack 11 is shown with the stacking direction of the battery cells 1 in the battery stack 11 aligned in the X direction and the width direction aligned in the Y direction. The Z direction, which is the front direction of the paper, is the height direction of the battery stack 11.

[0018] The outer surface 12 of the lid body 10 of each of the multiple battery cells 1 in the battery stack 11 faces the same direction. Specifically, in Fig. 2, the outer surface 12 of the lid body 10 of each of the multiple battery cells 1 in the battery stack 11 faces the front side of the page.

[0019] A first cell terminal group T1 is arranged in a row at one end Y1 of the battery stack 11 in the width direction. A second cell terminal group T2 is arranged in a row at the other end Y2 of the battery stack 11 in the width direction. Both the first cell terminal group T1 and the other cell terminal group T2 are composed of multiple cell terminals 6, 7. That is, the multiple battery cells 1 of the battery stack 11 are stacked with one of the positive cell terminal 6 and the negative cell terminal 7 aligned in the stacking direction at one end Y1 of the width direction and the other at the other end Y2 of the width direction.

[0020] In addition, in one cell terminal group T1, the positive electrode cell terminals 6 and the negative electrode cell terminals 7 are alternately arranged in the stacking direction. In the other cell terminal group T2, the positive electrode cell terminals 6 and the negative electrode cell terminals 7 are alternately arranged in the stacking direction. That is, the multiple cell terminals in the battery stack 11 are arranged such that the positive electrode cell terminals 6 and the negative electrode cell terminals 7 are alternately arranged in the stacking direction at one end Y1 side and the other end Y2 side in the width direction.

[0021] The busbar 30 of the battery module 20 is a member that connects the cell terminals 6, 7 to each other. The busbar 30 is a conductive flat plate-shaped member. The busbar 30 of this embodiment connects the positive cell terminal 6 of a battery cell 1 to the negative cell terminal 7 of another battery cell 1. The battery module 20 has two types of busbars 30: an adjacent connection busbar 31 and a jumper connection busbar 35. The multiple battery cells 1 in the battery stack 11 are electrically connected in series by the adjacent connection busbar 31 and the jumper connection busbar 35.

[0022] The adjacent connection busbar 31 and the jumper connection busbar 35 are connected to the cell terminals 6, 7 at connection points 32, respectively. The connection points 32 in this embodiment are formed by welding. That is, the adjacent connection busbar 31 and the jumper connection busbar 35 are joined to the positive cell terminal surface 6A of the positive cell terminal 6 and the negative cell terminal surface 7A of the negative cell terminal 7, respectively, by welding.

[0023] The adjacent connection busbar 31 connects the positive cell terminal 6 and the negative cell terminal 7 that are adjacent in the stacking direction. In other words, the cell terminals 6, 7 connected by the adjacent connection busbar 31 both belong to the same group of the one cell terminal group T1 and the other cell terminal group T2. The adjacent connection busbar 31 is a member extending from one of the connection points 32 with the positive cell terminal 6 and the connection points 32 with the negative cell terminal 7 to the other.

[0024] The jumper connection busbar 35 connects the positive cell terminal 6 and the negative cell terminal 7 arranged on both sides in the stacking direction of the cell terminals 6, 7 connected by the adjacent connection busbar 31. Therefore, both the cell terminals 6, 7 connected by the jumper connection busbar 35 belong to the same group of the one cell terminal group T1 and the other cell terminal group T2.

[0025] The jumper connection busbar 35 has a shape that bypasses, in the width direction, the adjacent connection busbar 31 located between the connected cell terminals 6, 7, and the cell terminals 6, 7 connected by the adjacent connection busbar 31. The jumper connection busbar 35 of this embodiment has a shape that bypasses, inward in the width direction, the adjacent connection busbar 31, and the cell terminals 6, 7 connected by the adjacent connection busbar 31.

[0026] Specifically, the jumper connection busbar 35 of this embodiment has a first width direction portion 36 extending inward in the width direction from the connection portion 32 with the positive cell terminal 6, and a second width direction portion 37 extending inward in the width direction from the connection portion 32 with the negative cell terminal 7. The jumper connection busbar 35 also has a stacking direction portion 38 extending in the stacking direction so as to connect the tips of the first width direction portion 36 and the second width direction portion 37 extending inward in the width direction from the cell terminals 6, 7.

[0027] 2, the jumper connection bus bar 35 has a detour shape that detours around the adjacent connection bus bar 31 in the width direction, so that the adjacent connection bus bar 31 and the jumper connection bus bar 35 do not interfere with each other. In other words, a gap is provided between the adjacent connection bus bar 31 and the jumper connection bus bar 35. Therefore, the adjacent connection bus bar 31 and the jumper connection bus bar 35 do not come into contact with each other and cause a short circuit. Note that to more reliably prevent contact between the adjacent connection bus bar 31 and the jumper connection bus bar 35, an insulating material may be placed between them.

[0028] Moreover, the adjacent connection bus bar 31 is arranged so as to be contained in the inner space surrounded by the jumper connection bus bar 35 having a detouring shape. Therefore, in the battery module 20 of this embodiment, the bus bar 30 is arranged in a space-saving manner. Specifically, as shown in FIG. 2, the width YL1 of the bus bar 30 located near the end of the battery stack 11 in the width direction is narrow. Therefore, in the battery module 20 of this embodiment, the bus bar 30 does not cover the vicinity of the center of the battery stack 11 in the width direction. Therefore, for example, the bus bar 30 does not prevent the discharge of gas from the gas discharge port 8 of the battery cell 1. Moreover, the bus bar 30 does not protrude outward in the width direction from the battery stack 11. In other words, the bus bar 30 does not increase the size of the battery module 20 in the width direction.

[0029] The battery module 20 also has a positive module terminal 21 and a negative module terminal 22. The positive module terminal 21 is connected to the positive cell terminal 6. The negative module terminal 22 is connected to the negative cell terminal 7. The positive cell terminal 6 to which the positive module terminal 21 is connected, and the negative cell terminal 7 to which the negative module terminal 22 is connected are positive and negative output end cell terminals located at both ends of the current path in the battery stack 11, respectively.

[0030] The positive module terminal 21 and the positive cell terminal 6, and the negative module terminal 22 and the negative cell terminal 7 are also joined by welding at connection points 32. The connection points 32 relating to the positive module terminal 21 and the negative module terminal 22 are also aligned with the connection point 32 of the bus bar 30 at the other end Y2 in the width direction. In the battery module 20, the multiple battery cells 1 that constitute the battery stack 11 can be charged or discharged via the positive module terminal 21 and the negative module terminal 22.

[0031] Here, in the battery module 20, the cell terminals 6, 7 are aligned in the stacking direction at one end Y1 side and the other end Y2 side of the battery stack 11. Furthermore, the widthwise positions of the connection points 32 between the cell terminals 6, 7 and the bus bar 30 are also aligned in the stacking direction at one end Y1 side and the other end Y2 side of the battery stack 11. That is, in the battery module 20, two rows of the connection points 32 aligned in the stacking direction are provided. For this reason, the welding equipment for forming the connection points 32 of the battery module 20 of this embodiment can be simple and inexpensive compared to a case in which the connection points are provided in a serpentine manner.

[0032] Also, for example, in general, in a battery module, a load may be applied to a cell terminal via a bus bar. Specifically, for example, when a load is applied to a bus bar such that a part of the bus bar moves away from a battery cell, a load may be applied to a cell terminal connected to the bus bar such that the cell terminal is tilted. Unlike the present embodiment, when the positions of the connection points are different for each cell terminal, the load applied through the bus bar is different for each cell terminal. In such a case, the cell terminal needs to be able to withstand various loads. In other words, if the structure of the cell terminal is made common, the structure of the cell terminal tends to be complex and large. Alternatively, the structure of the cell terminal needs to be different for each battery cell, and the battery module tends to become expensive as the variation of the battery cells increases.

[0033] In contrast, in the battery module 20 of this embodiment, the cell terminals 6, 7 and the connection points 32 are all aligned in the stacking direction, so that when comparing any two of the aligned cell terminals 6, 7, the connection points 32 are provided at approximately the same positions. Therefore, in the battery module 20 of this embodiment, the load that the cell terminals 6, 7 receive through the bus bar 30 does not vary significantly from one battery cell 1 to another. Therefore, the multiple battery cells 1 of the battery module 20 of this embodiment can adopt a common structure for the cell terminals 6, 7. Specifically, the positive cell terminals 6 of the multiple battery cells 1 can have the same structure. The same is true for the negative cell terminals 7. Furthermore, the structure of the common cell terminals 6, 7 can be made simple and small. Therefore, for example, the positive cell terminal surface 6A and the negative cell terminal surface 7A can be small. Therefore, the battery module 20 has a space-saving configuration for connecting the battery cells 1, and can be manufactured at low cost.

[0034] Furthermore, in the battery module 20, the connection points 32 are provided at approximately the same positions for each of the cell terminals 6, 7. Therefore, when forming the connection points 32 between the cell terminals 6, 7 and the bus bar 30 by welding, it is not necessary to set different welding conditions for each connection point 32. Moreover, all of the multiple connection points 32 can be appropriately formed under the same welding conditions.

[0035] Fig. 3 shows a cross-sectional view in the width direction of the battery module 20. More specifically, Fig. 3 is a cross-sectional view taken along the line AA shown in Fig. 2. As shown in Fig. 3, the battery module 20 has a facing member 40 provided to cover the outer surface of the battery stack 11.

[0036] The facing member 40 is provided on the upper surface side of the battery stack 11. The upper surface of the battery stack 11 is a surface formed by arranging the outer surfaces 12 of the lid bodies 10 of the battery cells 1. In other words, the facing member 40 is provided facing the outer surfaces 12 of the lid bodies 10 of the battery cells 1 in the battery stack 11.

[0037] Through holes 46 are formed in the facing member 40 at locations corresponding to the cell terminals 6, 7. As a result, the positive cell terminal surface 6A and the negative cell terminal surface 7A are exposed from the facing member 40.

[0038] The facing member 40 is provided with a first fitting portion 43 and a second fitting portion 44. In this embodiment, the first fitting portion 43 and the second fitting portion 44 are recesses that can restrict the position of the bus bar 30. The first fitting portion 43 is a recess into which the adjacent connection bus bar 31 is fitted. The second fitting portion 44 is a recess into which the jumper connection bus bar 35 is fitted. The bus bar 30 can be fitted from the outside of the facing member 40 into each of the first fitting portion 43 and the second fitting portion 44.

[0039] Through holes 46 of the facing member 40 provided at locations corresponding to the cell terminals 6, 7 open to the bottom surfaces of the first fitting portion 43 and the second fitting portion 44. As a result, the bus bars 30 are connected in contact with the positive cell terminal surface 6A and the negative cell terminal surface 7A, respectively.

[0040] The facing member 40 has through holes 45 at locations corresponding to the gas exhaust ports 8 of the battery cells 1. Therefore, in the battery module 20, gas is not prevented from being exhausted from the gas exhaust ports 8 of the battery cells 1.

[0041] Figures 4 to 6 show a comparative battery module different from the battery module 20 of the present embodiment. Note that the battery modules according to the comparative examples shown in Figures 4 to 6 also have multiple battery cells constituting a battery stack electrically connected in series by bus bars. The battery modules shown in Figures 4 and 5 are comparative examples of a configuration using bus bars that connect the terminals of two adjacent cells together.

[0042] 4 according to Comparative Example 1 includes a battery stack 111 configured by stacking a plurality of battery cells 101 in the thickness direction, and a bus bar 130. Each battery cell 101 is provided with a positive cell terminal 106 and a negative cell terminal 107. In addition, a gas exhaust port 108 is provided between the positive cell terminal 106 and the negative cell terminal 107.

[0043] In the battery module 100 according to Comparative Example 1, the cell terminals 106, 107 are also arranged aligned in the stacking direction at one end Y1 side and the other end Y2 side in the width direction of the battery stack 111. In the battery module 100 according to Comparative Example 1, two positive cell terminals 106 and two negative cell terminals 107 are alternately arranged in the stacking direction. That is, the positive cell terminal 106 is arranged next to one of the positive cell terminals 106 in the stacking direction, and the negative cell terminal 107 is arranged next to the other.

[0044] In the battery module 100 according to Comparative Example 1, the busbar 130 connects the cell terminals 106, 107 next to each other in the stacking direction. The busbars 130 are arranged alternately in the stacking direction between a direction that detours around the outside in the width direction and a direction that detours around the inside in the width direction. In the battery module 100 according to Comparative Example 1, the busbars 130 that detour around the outside in the width direction and the busbars 130 that detour around the inside in the width direction are provided overlapping each other in the width direction. As a result, in the battery module 100, the width YL2 of the busbars 130 located near the ends of the battery stack 111 in the width direction is wide.

[0045] In the battery module 100 according to Comparative Example 1, the connection points 132 between the cell terminals 106, 107 and the bus bar 130 are provided toward the center in the width direction. In such a battery module 100, the bus bar 130 having a wide width YL2 covers the gas exhaust port 108. For this reason, in the battery module 100 according to Comparative Example 1, there is a possibility that the bus bar 130 may prevent gas from being exhausted from the gas exhaust port 108 of the battery cell 101.

[0046] 5 shows a battery module 200 according to Comparative Example 2. The battery module 200 according to Comparative Example 2 is an example in which the connection points 132 between the cell terminals 106, 107 and the bus bar 130 are provided closer to both ends in the width direction than the battery module 100 according to Comparative Example 1. In such a battery module 100, the bus bar 130 having a wide width YL2 protrudes outward in the width direction beyond the battery stack 111. As a result, the battery module 200 according to Comparative Example 2 is larger in the width direction than the battery module 100 according to Comparative Example 1.

[0047] That is, in the battery module 100 according to Comparative Example 1 and the battery module 200 according to Comparative Example 2, the width YL2 of the bus bar 130 is wide, which may cause interference with other components. In contrast, in the battery module 20 according to the present embodiment, the width YL1 of the bus bar 30 is narrow. Thus, the battery module 20 is configured such that the bus bar 30 is unlikely to interfere with other components.

[0048] 6 is Comparative Example 3, in which battery cells 1 are connected to each other only by adjacent connection bus bars 31. In the battery module 300 according to Comparative Example 3, the cell terminals 6, 7 of the battery cell 1 are connected to the cell terminals 6, 7 of adjacent battery cells 1 in the stacking direction by the adjacent connection bus bars 31 at one end Y1 side and the other end Y2 side, respectively.

[0049] The battery module 300 according to Comparative Example 3 has a positive module terminal 321 and a negative module terminal 322 connected to the cell terminals 6 and 7 located at both ends of the current path in the battery stack 311. In the battery module 300 according to Comparative Example 3, only the adjacent connection bus bar 31 having a narrow width YL3 is used to connect the cell terminals 6 and 7. Therefore, in the battery module 300 according to Comparative Example 3, unlike Comparative Examples 1 and 2, the adjacent connection bus bar 31 is less likely to interfere with other components.

[0050] However, in the battery module 300 according to Comparative Example 3, there is only one bus bar provided to straddle two adjacent battery cells 1 in the battery stack 311. For this reason, the battery stack 311 is prone to deformation at the boundaries between the battery cells 1, and has low rigidity overall.

[0051] In contrast, in the battery module 20 of this embodiment, as shown in Fig. 2, the number of bus bars 30 provided to straddle two adjacent battery cells in the battery stack 11 is two. Therefore, the battery stack 11 as a whole is less likely to deform at the boundaries between the battery cells 1 and has high rigidity compared to the battery stack 311 of Comparative Example 3. Therefore, deformation of the battery module 20 due to vibration or the like is suppressed.

[0052] In the battery module 300 according to Comparative Example 3, the cell terminals 6 and 7 at both ends of the current path are located near both ends in the stacking direction of the battery stack 311. Therefore, the current paths for charging and discharging from the positive electrode module terminal 321 and the negative electrode module terminal 322 to the outside of the battery module 300 are separated on the side of the battery module 300. In such a case, the current paths for charging and discharging to the outside of the battery module 300 tend to be complicated.

[0053] 2, in the battery module 20 of this embodiment, the cell terminals 6, 7 located at both ends of the current path are both located near one end in the stacking direction of the battery stack 11. Therefore, the current paths for charging and discharging from the positive electrode module terminal 21 and the negative electrode module terminal 22 to the outside of the battery module 20 are close on the battery module 20 side. Therefore, in the battery module 20, the current paths for charging and discharging to other devices can be configured simply.

[0054] Depending on the arrangement of the positive and negative cell terminals in the battery stack, if multiple bus bars are arranged misaligned in the stacking direction during the bus bar attachment process during battery module manufacturing, a short circuit may occur. In contrast, in the battery module 20 of this embodiment, the one cell terminal group T1 and the other cell terminal group T2 are both formed by alternately arranging the positive electrode cell terminals 6 and the negative electrode cell terminals 7 in the stacking direction. In other words, the cell terminals 6, 7 in the battery stack 11 are alternately arranged as positive electrodes and negative electrodes in the stacking direction at one end Y1 side and the other end Y2 side in the width direction, respectively.

[0055] Therefore, in the battery module 20 of this embodiment, even if the multiple bus bars 30 are arranged misaligned in the stacking direction during manufacturing, there is no risk of a short circuit. In other words, when manufacturing the battery module 20, it is possible to arrange the multiple bus bars 30 at the same time. Therefore, the battery module 20 does not need to arrange the bus bars 30 in multiple steps separately, and the number of manufacturing steps can be reduced. As a result, the battery module 20 can be manufactured cheaply in a short time.

[0056] Furthermore, the facing member 40 is provided with first fitting portions 43 and second fitting portions 44 into which the multiple adjacent connection bus bars 31 and the jumper connection bus bars 35 are respectively fitted. Therefore, with the adjacent connection bus bars 31 and the jumper connection bus bars 35 fitted into the first fitting portions 43 and second fitting portions 44 of the facing member 40, the multiple bus bars 30 can be arranged simultaneously with respect to the cell terminals 6, 7. In other words, the process of collectively arranging the multiple bus bars 30 with respect to the cell terminals 6, 7 can be easily performed without short-circuiting the battery cells 1.

[0057] In the battery stack 11 of this embodiment, the positive cell terminals 6 other than the positive cell terminal 6 to which the positive module terminal 21 is connected are connected to the adjacent connection busbar 31 or the jumper connection busbar 35. In addition, the negative cell terminals 7 other than the negative cell terminal 7 to which the negative module terminal 22 is connected are also connected to the adjacent connection busbar 31 or the jumper connection busbar 35. In other words, either the adjacent connection busbar 31 or the jumper connection busbar 35 is connected to the cell terminals 6, 7 other than the positive and negative output end cell terminals located at both ends of the current path in the battery stack 11.

[0058] For this reason, the battery module 20 does not require a bus bar that connects the cell terminals 6, 7 located at one end Y1 side and the other end Y2 side of the battery stack 11. If there is a bus bar that connects the cell terminals 6, 7 so as to traverse the battery stack 11 in the width direction, the bus bar may cover the vicinity of the center of the battery stack 11. In other words, a bus bar that is provided so as to traverse the width direction may interfere with the configuration near the center of the battery stack 11. In contrast, the battery module 20 of this embodiment does not have a bus bar that is provided so as to traverse the width direction, and such a bus bar does not interfere with other configurations.

[0059] As described above in detail, the battery module 20 according to the present embodiment includes a battery stack 11 and a bus bar 30. The battery stack 11 is formed by stacking a plurality of flat-shaped battery cells 1. The bus bar 30 connects the cell terminals 6, 7 of the battery cells 1 to each other. The battery module 20 is formed by electrically connecting the plurality of battery cells 1 of the battery stack 11 in series by the bus bar 30. The plurality of battery cells 1 of the battery stack 11 are stacked with the outer surface 12 of the lid body 10, which is the outer surface on which the positive and negative cell terminals 6, 7 are both provided, facing the same direction. Furthermore, the plurality of battery cells 1 of the battery stack 11 are stacked with one of the positive and negative cell terminals 6, 7 on one end Y1 in the width direction and the other different from the one on the other end Y2 opposite to the one end Y1 in the width direction, aligned in the stacking direction. The width direction is a direction that intersects with the stacking direction on the outer surface 12 of the lid body 10. The battery module 20 also has an adjacent connection bus bar 31 and a jumper connection bus bar 35 as the bus bar 30. The adjacent connection bus bar 31 connects the cell terminals 6, 7 adjacent to each other in the stacking direction. The jumper connection bus bar 35 connects the cell terminals 6, 7 arranged on both sides of the cell terminals 6, 7 connected by the adjacent connection bus bar 31 in the stacking direction. Furthermore, the jumper connection bus bar 35 has a detour shape that detours the adjacent connection bus bar 31 and the cell terminals 6, 7 located between the cell terminals 6, 7 connected by the jumper connection bus bar 35 in the width direction. The positions of the connection points between the cell terminals 6, 7 and the bus bar 30 in the width direction are aligned in the stacking direction at each of the one end Y1 side and the other end Y2 side in the width direction. Therefore, the battery module 20 is realized in which the configuration for connecting the battery cells 1 is space-saving and can be manufactured at low cost.

[0060] The above-mentioned embodiments are merely examples and do not limit the present disclosure in any way. Therefore, the present disclosure can be modified and changed in various ways without departing from the spirit and scope of the present disclosure.

[0061] For example, in the above embodiment, an example of the jumper connection busbar 35 has been described that has a shape that detours the adjacent connection busbar 31 and the positive cell terminal 6 and the negative cell terminal 7 connected by the adjacent connection busbar 31 inward in the width direction. However, the jumper connection busbar may have a shape that detours, for example, outward in the width direction. In addition, it is preferable that the inside and outside directions of the detour shape of the jumper connection busbar are the same for the group on one end side of the width direction of the battery stack (for connecting one cell terminal group) and the group on the other end side (for connecting the other cell terminal group). This is because the width of the busbar can be narrowed while aligning the connection points with the cell terminals.

[0062] In the above embodiment, the connection points 32 between the cell terminals 6, 7 and the bus bar 30 are described as being formed by welding. However, the connection points between the cell terminals and the bus bar may be formed using, for example, a screw structure.

[0063] In the above embodiment, an example has been described in which facing member 40 is provided with first fitting portion 43 and second fitting portion 44 into which busbar 30 is fitted from the outside. However, the facing member may be provided with fitting portions into which busbar 30 is fitted from the inside. In addition, the fitting portions of the facing member may be configured to hold busbar 30 by, for example, a snap-fit ​​structure or the like.

[0064] Moreover, the number of battery cells 1 constituting the battery stack 11 shown in Fig. 2 and elsewhere is merely an example, and is of course not limited to the number shown in Fig. 2. Moreover, the outer terminal surface on which both the positive and negative cell terminals of the battery cells are provided is not limited to the outer surface of the lid. Moreover, there are no particular limitations on the type of battery (nickel-metal hydride battery, lithium-ion battery, etc.) to which the above-described embodiments are applicable.

[0065] The above-disclosed technology also includes the following means 1 to 3. [Means 1] The battery module according to claim 1, The cell terminals in the battery stack are arranged such that positive electrodes and negative electrodes are alternately arranged in the stacking direction at each of the one end side and the other end side in the width direction.

[0066] [Means 2] The battery module according to the first aspect of the present invention comprises: A battery module in which either the adjacent connection bus bar or the jumper connection bus bar is connected to the cell terminals other than the positive and negative output end cell terminals, which are the positive and negative cell terminals located at both ends of the current path in the battery stack.

[0067] [Means 3] The battery module according to the first or second aspect of the present invention, a facing member provided facing the terminal outer surface of the battery cell in the battery stack, The facing member is provided with fitting portions into which the bus bars are respectively fitted. [Explanation of symbols]

[0068] 1: Battery cell 2: Exterior body 4: Box body 6: Positive cell terminal 7: Negative cell terminal 10: Lid 11: Battery stack 12: External surface 20: Battery module 21: Positive module terminal 22: Negative module terminal 30: Busbar 31: Adjacent connecting busbar 32: Connection point 35: Jumper connection busbar 42: Facing parts 43: First fitting portion 44: Second fitting part

Claims

1. A battery module comprising: a battery stack formed by stacking a plurality of flat-shaped battery cells; and a bus bar connecting cell terminals of the battery cells, the plurality of battery cells being electrically connected in series by the bus bar, The plurality of battery cells of the battery stack include The positive and negative cell terminals are provided on outer terminal surfaces facing in the same direction, one of the positive and negative cell terminals is stacked on one end side of a width direction that is a direction intersecting the stacking direction of the battery cells on the terminal outer surface, and the other cell terminal different from the one cell terminal is stacked on the other end side opposite to the one end side in the width direction, while being aligned in the stacking direction, As the bus bar, an adjacent connection bus bar connecting the cell terminals adjacent to each other in the stacking direction; a jumper connection bus bar that connects the cell terminals arranged on both sides in the stacking direction of the two cell terminals connected by the adjacent connection bus bar, the jumper connection bus bar has a detouring shape that detours around the adjacent connection bus bar and the cell terminal located between the two cell terminals connected by the jumper connection bus bar in the width direction, a battery module in which positions in the width direction of connection points between the cell terminals and the bus bars are aligned in the stacking direction at each of the one end side and the other end side in the width direction.

2. The battery module according to claim 1 , The cell terminals in the battery stack are arranged such that positive electrodes and negative electrodes are alternately arranged in the stacking direction at each of the one end side and the other end side in the width direction.

3. The battery module according to claim 2, A battery module in which either the adjacent connection bus bar or the jumper connection bus bar is connected to the cell terminals other than the positive and negative output end cell terminals, which are the positive and negative cell terminals located at both ends of the current path in the battery stack.

4. The battery module according to claim 2 or 3, a facing member provided facing the terminal outer surface of the battery cell in the battery stack, The facing member is provided with fitting portions into which the bus bars are respectively fitted.

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