JP2023163671A - battery module - Google Patents

Abstract

To improve the operability for serially connecting at least one first cell and at least one second cell to each other.SOLUTION: A battery module 10 includes a first positive electrode tab 132A and a second negative electrode tab 134B. A first end part B1 of the first positive electrode tab 132A is bent to a predetermined direction on the basis of a first bending part C1. The second positive electrode tab 134B is joined to the first positive electrode tab 132A. A second end part B2 of the second negative electrode tag 134B is bent to a predetermined direction on the basis of a second bending part C2. The first end part B1 and the second end part B2 are displaced to the other side in the predetermined direction with respect to a virtual bisector BS of a virtual line segment LS which connects a first base end A1 of the first positive electrode tag 132A and a second base end A2 of the second negative electrode tag 134B.SELECTED DRAWING: Figure 3

Description

The present invention relates to a battery module.

In recent years, various battery modules including a plurality of battery cells have been developed. Each battery cell includes a battery element, an exterior material that seals the battery element, and a positive electrode tab and a negative electrode tab pulled out from the exterior material.

Patent Document 1 describes an example of a battery module. In this battery module, the positive electrode tab and the negative electrode tab are pulled out from opposite sides of the exterior material. In this battery module, the positive electrode tabs of a single battery cell or a plurality of battery cells connected in parallel and the negative electrode tabs of a single battery cell or a plurality of battery cells connected in parallel are joined to each other. The positive electrode tab and the negative electrode tab are folded back between a battery cell provided with the positive electrode tab and a battery cell provided with the negative electrode tab.

Patent Document 2 describes an example of a battery module. In this battery module, a plurality of tip portions of a plurality of positive electrode tabs or a plurality of negative electrode tabs of a plurality of battery cells are bent in the direction.

Patent Document 3 describes an example of a battery module. In this battery module, the tips of the positive electrode tab and the negative electrode tab are bent.

International Publication No. 2006/109610 International Publication No. 2016/020999 International Publication No. 2011/027817

For example, as described in Patent Document 1, a positive electrode tab and a negative electrode tab may be folded back between at least one battery cell and at least one other battery cell. However, in this case, the workability for connecting at least one battery cell and at least one other battery cell in series may decrease.

One example of the object of the present invention is to improve workability for connecting at least one battery cell and at least one other battery cell in series. Other objects of the invention will become apparent from the description herein.

One aspect of the present invention is as follows.
[1]
at least one positive electrode tab having a predetermined first tip portion bent in a predetermined direction around a predetermined first bending portion;
at least one negative electrode tab joined to the at least one positive electrode tab and having a predetermined second tip bent in the predetermined direction around a predetermined second bending portion;
Equipped with
The first bent portion and the second bent portion bisect a virtual line segment connecting a predetermined first base end of the at least one positive electrode tab and a predetermined second base end of the at least one negative electrode tab. The battery module is shifted to the opposite side of the predetermined direction with respect to the line.
[2]
The battery module according to [1], further comprising a voltage detection section joined to at least one of the first tip and the second tip.
[3]
comprising a plurality of tab groups including at least one positive electrode tab and at least one negative electrode tab joined to each other,
A battery module, wherein the tip portions of each of the plurality of tab groups are bent in the same direction.
[4]
The battery module according to [3], further comprising a plurality of voltage detection sections joined to the tip portions of the plurality of tab groups.
[5]
at least one positive electrode tab with a predetermined first tip bent in a predetermined direction;
at least one negative electrode tab joined to the at least one positive electrode tab and having a predetermined second tip bent in the predetermined direction;
a voltage detection unit joined to at least one of the first tip and the second tip;
A battery module comprising:

According to the above aspect of the present invention, it is possible to improve the workability for connecting at least one battery cell and at least one other battery cell in series.

FIG. 2 is a perspective view of the front portion of the battery module according to the embodiment. FIG. 2 is a sectional view taken along the line AA' in FIG. 1; It is a top view of the front part of a 1st battery cell and a 2nd battery cell among a plurality of battery cells concerning an embodiment. It is a figure for explaining the 1st example of the manufacturing method of the battery module concerning an embodiment. It is a figure for explaining the 1st example of the manufacturing method of the battery module concerning an embodiment. It is a figure for explaining the 1st example of the manufacturing method of the battery module concerning an embodiment. It is a figure for explaining the manufacturing method of the battery module concerning a comparison form. It is a figure for explaining the manufacturing method of the battery module concerning a comparison form. It is a figure for explaining the 2nd example of the manufacturing method of the battery module concerning an embodiment. It is a figure for explaining the 2nd example of the manufacturing method of the battery module concerning an embodiment. 7 is a top view of a front portion of a battery module according to modification 1. FIG. FIG. 7 is a top view of a front portion of a battery module according to Modification 2. FIG.

Embodiments of the present invention will be described below with reference to the drawings. In all the drawings, similar components are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

FIG. 1 is a perspective view of a front portion of a battery module 10 according to an embodiment. FIG. 2 is a sectional view taken along line AA' in FIG.

In each figure, arrows indicating the X direction, Y direction, and Z direction are shown for explanation. The X direction indicates the front-rear direction of the battery module 10. Hereinafter, unless otherwise specified, the tip side of the arrow indicating the X direction will be the rear side of the battery module 10. Hereinafter, unless otherwise specified, the base end side of the arrow indicating the X direction will be the front side of the battery module 10. The Y direction is perpendicular to the X direction. The Y direction indicates the left and right direction of the battery module 10. Hereinafter, unless otherwise specified, the tip side of the arrow indicating the Y direction will be the left side of the battery module 10. Hereinafter, unless otherwise specified, the base end side of the arrow indicating the Y direction will be the right side of the battery module 10. The Z direction is perpendicular to both the X direction and the Y direction. The Z direction indicates the vertical direction of the battery module 10. Hereinafter, unless otherwise specified, the tip side of the arrow indicating the Z direction will be the upper side of the battery module 10. Hereinafter, unless otherwise specified, the base end side of the arrow indicating the Z direction will be referred to as the lower side of the battery module 10. In FIG. 2, a white circle with black dots indicating the Z direction indicates the upper side of the battery module 10 from the back to the front of the page, and the bottom side of the battery module 10 from the front to the back of the page. . However, the relationships between the X direction, Y direction, and Z direction and the front-rear direction, left-right direction, and up-down direction of the battery module 10 are not limited to the above-mentioned example. These relationships differ depending on the actual arrangement of battery modules 10.

The battery module 10 will be described with reference to FIG. 1 and, if necessary, FIG. 2.

The battery module 10 includes a plurality of battery cells 100 and a voltage detection section 200.

In the example shown in FIG. 1, four battery cells 100 are illustratively illustrated. However, the number of battery cells 100 included in the battery module 10 is not limited to the example shown in FIG. 1. The plurality of battery cells 100 are stacked in the Y direction. In the example shown in FIG. 1, the longitudinal direction of each battery cell 100 is approximately parallel to the X direction. The lateral direction of each battery cell 100 is approximately parallel to the Z direction. The thickness direction of each battery cell 100 is approximately parallel to the Y direction. However, the shape of each battery cell 100 is not limited to the example shown in FIG. 1.

As shown in FIGS. 1 and 2, each battery cell 100 has a battery element 110, an exterior material 120, a positive electrode tab 132, and a negative electrode tab 134.

As shown in FIG. 2, battery element 110 includes multiple positive electrodes 112 and multiple negative electrodes 114. The plurality of positive electrodes 112 and the plurality of negative electrodes 114 are alternately stacked in the Y direction. The positive electrode 112 and negative electrode 114 adjacent to each other in the Y direction are separated from each other by a separator (not shown). However, the structure of battery element 110 is not limited to this example.

As shown in FIG. 2, the exterior material 120 seals the battery element 110 and an electrolytic solution (not shown).

The positive electrode tab 132 is electrically connected to the plurality of positive electrodes 112. The electrical connection between the positive electrode tab 132 and the plurality of positive electrodes 112 will be described with reference to the example shown in FIG. In the example shown in FIG. 2, positive electrode tab 132 is located in front of battery element 110. A base end A on the rear end side of the positive electrode tab 132 is located within a region sealed by the exterior material 120. In the example shown in FIG. 2, the positive electrode tab 132 extends diagonally forward to the right from the base end A when viewed from above. The positive electrode tab 132 is joined to the plurality of positive electrode current collector foils 112a. In the example shown in FIG. 2, the plurality of positive electrode current collector foils 112a are pulled out from the plurality of positive electrodes 112 toward the front of the battery element 110, and are integrally bundled in the vicinity of the base end A of the positive electrode tab 132. ing. Thereby, the positive electrode tab 132 is electrically connected to the plurality of positive electrodes 112. Similarly to the example shown in FIG. 2, the negative electrode tab 134 is electrically connected to the plurality of negative electrodes 114 via a plurality of negative electrode current collector foils (not shown) drawn out from the plurality of negative electrodes 114.

In each battery cell 100, the positive electrode tab 132 and the negative electrode tab 134 are drawn out from opposite sides of the exterior material 120 in the X direction. The positive electrode tab 132 is made of aluminum, for example. The negative electrode tab 134 is made of copper, for example. In the battery cells 100 adjacent in the Y direction, the positive electrode tabs 132 and negative electrode tabs 134 of each battery cell 100 are alternated in the X direction. Thus, for example, in the example shown in FIG. It has a negative electrode tab 134. In the example shown in FIG. 1, the battery cell 100 located second from the left has a negative electrode tab 134 located in front of the battery cell 100, and a positive electrode (not shown) located in the rear of the battery cell 100. It has a tab 132.

Battery cells 100 adjacent to each other in the Y direction have a tab group 130 located in front or behind the adjacent battery cells 100. Each tab group 130 includes a positive electrode tab 132 and a negative electrode tab 134 that are joined to each other. Each tab group 130 includes a tip group BG. The tip group BG includes the tip of the positive electrode tab 132 and the tip of the negative electrode tab 134. In the example shown in FIG. 1, the plurality of tip groups BG located in front of the battery module 10 are all bent in the same direction when viewed from above. Thereby, the tip group BG is substantially parallel to the Y direction. Therefore, the voltage detection section 200 can be easily joined to the front surface of the tip group BG with the thickness direction of the voltage detection section 200 being substantially parallel to the X direction. A first joint portion 150 is provided in the tip group BG. The positive electrode tab 132 and the negative electrode tab 134 included in each tab group 130 are joined to each other at a first joint portion 150 . The first joint 150 is formed, for example, by laser welding. However, the method of forming the first joint portion 150 is not limited to this example.

The plurality of tab groups 130 located in front of the plurality of battery cells 100 and the plurality of tab groups 130 (not shown) located in the rear of the plurality of battery cells 100 are arranged alternately in the Y direction. Thereby, battery cells 100 adjacent to each other in the Y direction are connected in series. For example, in the example shown in FIG. 1, the two battery cells 100 on the left side are connected in series via a tab group 130 located in front of these battery cells 100. In the example shown in FIG. 1, the two central battery cells 100 are connected in series via a tab group 130 (not shown) located behind these battery cells 100.

Each of the plurality of voltage detection sections 200 is joined to each of the plurality of tip groups BG. Each voltage detection section 200 is made of a conductor such as metal, for example. In the example shown in FIG. 2, a voltage detection section 200 is joined to the front surface of the tip group BG located in front of the battery module 10. Each voltage detection section 200 and each tip group BG are joined to each other at a second joint 250. The second joint portion 250 is formed, for example, by laser welding. However, the method of forming the second joint portion 250 is not limited to this example.

Each of the plurality of voltage detection units 200 is electrically connected to each of a plurality of voltage detection lines (not shown). Therefore, it is possible to detect the voltage of each tab group 130 by each voltage detection section 200 and each voltage detection line.

FIG. 3 is a top view of the front portions of the first battery cell 100A and the second battery cell 100B among the plurality of battery cells 100 according to the embodiment.

The first battery cell 100A and the second battery cell 100B are adjacent to each other in the Y direction. When viewed from above, the first battery cell 100A is located on the left side of the second battery cell 100B. When viewed from above, the second battery cell 100B is located on the right side of the first battery cell 100A.

The first battery cell 100A has a first positive electrode tab 132A. The first positive electrode tab 132A includes a first base end A1, a first tip end B1, and a first bent part C1. The second battery cell 100B has a second negative electrode tab 134B. The second negative electrode tab 134B includes a second base end A2, a second tip B2, and a second bent part C2. The first positive electrode tab 132A and the second negative electrode tab 134B constitute a tab group 130. The first tip B1 and the second tip B2 constitute a tip group BG.

FIG. 3 shows a virtual line segment LS and a virtual bisector BS. Seen from above, the virtual line segment LS connects the first base end A1 and the second base end A2. When viewed from above, the virtual line segment LS is approximately parallel to the Y direction. When viewed from above, the virtual bisector BS is a perpendicular bisector of the virtual line segment LS. When viewed from above, the virtual bisector BS is approximately parallel to the X direction.

When viewed from above, the first tip portion B1 is bent toward the left around the first bent portion C1. When viewed from above, the second tip portion B2 is bent leftward about the second bent portion C2. When viewed from above, the first bent portion C1 and the second bent portion C2 are shifted to the right with respect to the virtual bisector BS. That is, the first bent portion C1 and the second bent portion C2 are shifted from the virtual bisector BS to the opposite side of the direction in which the first tip portion B1 and the second tip portion B2 are bent.

When viewed from above, the portion between the first base end A1 and the first bent portion C1 of the first positive electrode tab 132A is inclined at a first angle θ1 with respect to the X direction. When viewed from above, the portion between the second tip B2 and the second bent portion C2 of the second negative electrode tab 134B is inclined at a second angle θ2 with respect to the X direction. As described above, when viewed from above, the first bent portion C1 and the second bent portion C2 are shifted to the right with respect to the virtual bisector BS. As a result, the second angle θ2 is smaller than the first angle θ1.

In the embodiment, it is possible to suppress fluctuations in the positions of the first base end A1 and second base end A2 and fluctuations in the first angle θ1 and second angle θ2 due to bending of the first positive electrode tab 132A and the second negative electrode tab 134B. Can be done. Therefore, it is possible to suppress phenomena such as disconnection of the current collector foil due to fluctuations in the positions of the first base end A1 and the second base end A2 and fluctuations in the first angle θ1 and the second angle θ2. Specifically, when viewed from above, the radius of curvature of the first bent portion C1 of the first positive electrode tab 132A is smaller than the radius of curvature of the second bent portion C2 of the second negative electrode tab 134B. In the embodiment, by shifting the first bent portion C1 toward the second bent portion C2 side when viewed from above, the length of the first bent portion C1 of the first positive electrode tab 132A and its periphery and the length of the second negative electrode tab 134B are adjusted. The lengths of the second bent portion C2 and its periphery can be made equal. Therefore, in the embodiment, when viewed from above, the first base end A1 is prevented from moving rearward due to the remaining length of the first bent portion C1 of the first positive electrode tab 132A and its periphery. Can be done. Further, in the embodiment, when viewed from above, the second base end A2 can be prevented from moving forward due to the insufficient length of the second bent portion C2 of the second negative electrode tab 134B and its surroundings. can.

In the example shown in FIG. 3, the tip group BG is bent toward the left when viewed from above. However, when viewed from above, the tip group BG may be bent toward the right. In this case, the first bent portion C1 and the second bent portion C2 can be shifted to the left with respect to the virtual bisector BS.

4 to 6 are diagrams for explaining a first example of the method for manufacturing the battery module 10 according to the embodiment. In this first example, the battery module 10 according to the embodiment is manufactured as follows.

First, the first battery cell 100A and the second battery cell 100B are arranged next to each other in the Y direction with the first positive electrode tab 132A and the second negative electrode tab 134B pulled out forward.

Next, the first tip portion B1 and the second tip portion B2 are joined to each other to form the first joint portion 150. The first tip portion B1 and the second tip portion B2 are joined by laser welding, for example. However, the method of joining the first tip B1 and the second tip B2 is not limited to this example. In the laser welding in the embodiment, the laser can be irradiated from both left and right sides of the first tip B1 and the second tip B2. Therefore, the workability of joining the first tip portion B1 and the second tip portion B2 can be improved.

Note that the order of the steps of joining the first tip portion B1 and the second negative electrode tab 134B is not limited to the example described above. For example, after the first tip B1 and the second tip B2 are bent as described below, the first tip B1 and the second tip B2 may be joined.

Next, as shown in FIG. 4, the first tip B1 and the second tip B2 are sandwiched between the pair of bending fingers 300A.

Next, as shown in FIG. 5, the pair of bending fingers 300A are rotated clockwise when viewed from above. As a result, the first tip portion B1 and the second tip portion B2 are bent toward the left when viewed from above. In the example shown in FIG. 5, the first positive electrode tab 132A and the second negative electrode tab 134B are arranged so that the first bent portion C1 and the second bent portion C2 are shifted to the right with respect to the virtual bisector BS when viewed from above. is folded. Therefore, as described above, it is possible to suppress fluctuations in the positions of the first base end A1 and the second base end A2 due to bending of the first positive electrode tab 132A and the second negative electrode tab 134B.

Next, the pair of bending fingers 300A is removed from the tab group 130. In this case, the bending finger 300A located at the rear of the tip group BG can be moved toward the front of the tab group 130 through the space on the left side of the tip group BG when viewed from above. In the embodiment, a plurality of tip end groups BG located at the front of the battery module 10 are bent in the same direction. For example, in the example shown in FIG. 1, the tip groups BG of the tab groups 130 adjacent to each other in the Y direction are both bent toward the left when viewed from above. In this example, the left tip group BG shown in FIG. 1 is bent toward the right when viewed from above, and the right tip group BG shown in FIG. 1 is bent toward the left when viewed from above. The width in the Y direction of the space between the tip groups BG adjacent in the Y direction can be increased compared to the case where the Y direction is the same as that in the Y direction. Therefore, in the embodiment, the bending finger 300A located at the rear of the right tip group BG shown in FIG. 1 is taken out toward the front of the tab group 130 through the space between the tip group BG adjacent in the Y direction. It's getting easier. Therefore, in the embodiment, the workability for removing the pair of bending fingers 300A from the tab group 130 can be improved.

Next, as shown in FIG. 6, with the voltage detection section 200 disposed in front of the tip group BG, the tip group BG and the voltage detection section 200 are sandwiched between the first laser finger 410A and the second laser finger 420A. The first laser finger 410A is arranged in front of the voltage detection section 200. The second laser finger 420A is arranged behind the tip group BG. Next, a laser beam is irradiated toward the front surface of the voltage detection section 200 through a laser hole 412A provided in the first laser finger 410A. As a result, a second joint 250 is formed, and the voltage detection section 200 is joined to the tip group BG.

In the example shown in FIG. 6, a space for passing the second laser finger 420A behind the tip group BG is provided on the left side of the tip group BG when viewed from above. Therefore, the second laser finger 420A can be arranged behind the tip group BG without moving the second laser finger 420A upward or downward. Therefore, the workability for arranging the second laser finger 420A behind the tip group BG can be improved.

Note that the order of the steps of joining the voltage detection section 200 to the tip group BG is not limited to the example described above. For example, the voltage detection unit 200 may be joined to the tip group BG before the tip group BG is bent.

7 and 8 are diagrams for explaining a method of manufacturing a battery module according to a comparative embodiment. The method for manufacturing the battery module according to the comparative embodiment is the same as the method for manufacturing the battery module 10 according to the embodiment, except for the following points.

First, the first battery cell 100A and the second battery cell 100B are arranged in the X direction with the first tip B1 and the second tip B2 overlapping in the Y direction.

Next, as shown in FIG. 7, the first tip B1 and the second tip B2 are sandwiched between the pair of first bending fingers 310K. A portion between the first base end A1 and the first tip B1 of the first positive electrode tab 132A is sandwiched between the pair of second bending fingers 320K. A portion between the second base end A2 and the second tip B2 of the second negative electrode tab 134B is sandwiched between a pair of third bending fingers 330K.

Next, with the position of the pair of third bending fingers 330K fixed, the pair of first bending fingers 310K and the pair of third bending fingers 330K are rotated clockwise when viewed from above. As a result, the portion between the pair of first bending fingers 310K and the pair of third bending fingers 330K of the second negative electrode tab 134B is bent at a substantially right angle when viewed from above.

Next, as shown in FIG. 8, while the positions of the pair of first folding fingers 310K and the pair of third folding fingers 330K are fixed, the pair of second folding fingers 320K is rotated clockwise when viewed from above. . As a result, the portion between the pair of first bending fingers 310K and the pair of second bending fingers 320K of the first positive electrode tab 132A is bent at a substantially right angle when viewed from above. Thereby, the first positive electrode tab 132A and the second negative electrode tab 134B form a folded tab group 130K. The folding tab group 130K is folded back between the first base end A1 and the second base end A2.

Next, the voltage detection section 200 is joined to the front surface of the first tip B1.

The embodiments shown in FIGS. 4 to 6 will be compared with the comparative embodiments shown in FIGS. 7 and 8.

In the comparative embodiment, the shorter the distance in the Y direction between the first base end A1 and the second base end A2 of the folding tab group 130K, the more the first folding finger 310K and the second folding finger are located inside the folding tab group 130K. It is necessary to reduce the width of the third bending finger 320K and the third bending finger 330K in the direction perpendicular to the Z direction. The narrower the width of each finger, the greater the deflection of each finger in the Z direction. Therefore, in the comparative embodiment, the shorter the distance between the first base end A1 and the second base end A2 in the Y direction of the folded tab group 130K, the more difficult it may be to form the folded tab group 130K. In contrast, in the embodiment, the first distal end B1 and the second distal end B2 can be bent regardless of the distance in the Y direction between the first proximal end A1 and the second proximal end A2. Therefore, in the embodiment, the workability for bending the tip group BG can be improved compared to the comparative embodiment.

In the comparative embodiment, in order to remove the first folding finger 310K, second folding finger 320K, and third folding finger 330K located inside the folding tab group 130K, it is necessary to move these fingers upward or downward. On the other hand, in the embodiment, the bending finger 300A located at the rear of the tip group BG can be taken out through the space between the tip groups BG adjacent to each other in the Y direction. Therefore, in the embodiment, the bending finger 300A located at the rear of the tip group BG can be removed without moving the bending finger 300A upward or downward. Therefore, in the embodiment, compared to the comparative embodiment, it is possible to improve the workability for removing the bending finger 300A located at the rear of the tip group BG.

9 and 10 are diagrams for explaining a second example of the method for manufacturing the battery module 10 according to the embodiment. The second example shown in FIGS. 9 and 10 is similar to the first example shown in FIGS. 4 to 6 except for the following points.

As shown in FIG. 9, a portion between the first tip B1 and the first base end A1 of the first positive electrode tab 132A and a portion between the second tip B2 and the second base end A2 of the second negative electrode tab 134B. and is sandwiched between a first fixed folding finger 312B and a second fixed folding finger 314B. When viewed from above, the first fixed bending finger 312B is arranged on the left side of the first positive electrode tab 132A. When viewed from above, the second fixed bending finger 314B is located on the right side of the second negative electrode tab 134B. Next, the movable bending finger 320B is arranged in front of the second fixed bending finger 314B and on the right side of the second tip B2 when viewed from above.

Next, as shown in FIG. 10, the movable bending finger 320B is rotated clockwise when viewed from above. As a result, the tip group BG is bent toward the left when viewed from above.

FIG. 11 is a top view of the front portion of a battery module 10A according to modification 1. The battery module 10A according to Modification 1 is the same as the battery module 10 according to the embodiment except for the following points.

In Modification 1, the tip group BG is bent toward the left when viewed from above. The first bent portion C1 and the second bent portion C2 are shifted to the right with respect to the virtual bisector BS. The portion between the first base end A1 and the first bent portion C1 of the first positive electrode tab 132A is inclined at an angle θ with respect to the X direction. On the other hand, the portion between the second base end A2 and the second bent portion C2 of the second negative electrode tab 134B is substantially parallel to the X direction. In Modification 1 as well, it is possible to suppress variations in the positions of the first base end A1 and the second base end A2 due to bending of the first positive electrode tab 132A and the second negative electrode tab 134B.

FIG. 12 is a top view of the front portion of a battery module 10B according to modification 2. The battery module 10B according to Modification 2 is the same as the battery module 10 according to the embodiment except for the following points.

A battery module 10B according to modification 2 includes four battery cells 100 shown in FIG. 12. In the example shown in FIG. 12, the two battery cells 100 on the left side are connected in parallel. In the example shown in FIG. 12, the two battery cells 100 on the right side are connected in parallel. The two parallel-connected battery cells 100 on the left side shown in FIG. 12 and the two parallel-connected battery cells 100 on the right side shown in FIG. 12 are connected in series.

Two positive electrode tabs 132 are pulled out toward the front from the two parallel-connected battery cells 100 on the left side shown in FIG. Two negative electrode tabs 134 are pulled out toward the front from the two parallel-connected battery cells 100 on the right side shown in FIG. These tabs are joined together. Specifically, the tip group BG including the tips of these tabs is bent toward the left when viewed from above. In the tip group BG, the tips of the tabs described above are joined to each other. In the example shown in FIG. 12, the voltage detection section 200 is joined to the front surface of the tip group BG. In Modification 2, similarly to the embodiment, the two parallel-connected battery cells 100 on the left side shown in FIG. 12 and the two parallel-connected battery cells 100 on the right side shown in FIG. 12 are connected in series. The workability for connection can be improved.

In addition, in the example shown in FIG. 12, a battery cell group including two battery cells 100 connected in parallel is connected in series. However, even when a battery cell group including three or more parallel-connected battery cells 100 is connected in series, a structure similar to the structure described using FIG. 12 can be adopted.

Although the embodiments of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various configurations other than those described above may also be adopted.

10, 10A, 10B Battery module 100 Battery cell 100A First battery cell 100B Second battery cell 110 Battery element 112 Positive electrode 112a Positive electrode collector foil 114 Negative electrode 120 Exterior material 130 Tab group 130K Folded tab group 132 Positive electrode tab 132A First positive electrode tab 134 Negative electrode tab 134B Second negative electrode tab 150 First joint part 200 Voltage detection part 250 Second joint part 300A Bending finger 310K First bending finger 312B First fixed bending finger 314B Second fixed bending finger 320B Movable bending finger 320K Second bending Finger 330K Third bending finger 410A First laser finger 412A Laser hole 420A Second laser finger A Base end A1 First base end A2 Second base end B1 First tip B2 Second tip BG Tip group BS Virtual second class Segment line C1 First bent part C2 Second bent part LS Virtual line segment

Claims (5)

at least one positive electrode tab having a predetermined first tip portion bent in a predetermined direction around a predetermined first bending portion;
at least one negative electrode tab joined to the at least one positive electrode tab and having a predetermined second tip bent in the predetermined direction around a predetermined second bending portion;
Equipped with
The first bent portion and the second bent portion bisect a virtual line segment connecting a predetermined first base end of the at least one positive electrode tab and a predetermined second base end of the at least one negative electrode tab. The battery module is shifted to the opposite side of the predetermined direction with respect to the line. The battery module according to claim 1, further comprising a voltage detection section joined to at least one of the first tip and the second tip. comprising a plurality of tab groups including at least one positive electrode tab and at least one negative electrode tab joined to each other,
A battery module, wherein the tip portions of each of the plurality of tab groups are bent in the same direction. The battery module according to claim 3, further comprising a plurality of voltage detection sections joined to the tip ends of the plurality of tab groups. at least one positive electrode tab with a predetermined first tip bent in a predetermined direction;
at least one negative electrode tab joined to the at least one positive electrode tab and having a predetermined second tip bent in the predetermined direction;
a voltage detection unit joined to at least one of the first tip and the second tip;
A battery module comprising:

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