Battery module

Abstract

To secure electric insulation between different lead parts.SOLUTION: A first voltage detection device 30A includes a plurality of first voltage detection units 310A connected to a plurality of lead parts 110 of a plurality of battery cells 100, a first holder 300A that holds the first voltage detection units 310A, and an insulator provided in the first holder 300A and existing between the lead parts 110 that are at least partially different.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a voltage detection device and a battery module.

Background Art

[0002] A battery module such as a lithium ion secondary battery may include a plurality of stacked battery cells. In such a battery module, a plurality of battery cells are electrically connected to each other by a positive electrode lead and a negative electrode lead drawn from an exterior material of the battery cell.

[0003] Patent Document 1 describes an example of a battery module. In the battery module, a positive electrode lead of one battery cell and a negative electrode lead of another battery cell are joined. Thereby, one battery cell and another battery cell are electrically connected to each other via a lead portion including the joined positive electrode lead and negative electrode lead.

[0004] Patent Documents 2 and 3 describe an example of a battery module. In the battery module, a positive electrode lead of one battery cell and a negative electrode lead of another battery cell are electrically connected to each other via a bus bar.

[0005] Patent Document 4 describes an example of a battery module. In the battery module, a positive electrode fastening terminal welded to a positive electrode lead of one battery cell and a negative electrode fastening terminal welded to a negative electrode lead of another battery cell are electrically connected to each other.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0007] For example, as described in Patent Document 1, when one battery cell and another battery cell are joined to each other via lead portions, there is a risk that electrical insulation between different lead portions cannot be ensured. For example, when the battery module receives a large impact, the lead portions may be deformed. In this case, adjacent lead portions may come into contact with each other, and there is a risk of a short circuit occurring between the adjacent lead portions.

[0008] An example of the object of the present invention is to ensure electrical insulation between different lead portions. Other objects of the present invention will become apparent from the description herein.

Means for Solving the Problems

[0009] One aspect of the present invention is a plurality of voltage detection units connected to a plurality of lead portions of a plurality of battery cells, a holder for holding the plurality of voltage detection units, an insulator provided on the holder and at least a part of which is located between different lead portions, and a voltage detection device including the same.

[0010] Another aspect of the present invention is the voltage detection device, the plurality of battery cells having the plurality of lead portions electrically connected to the plurality of voltage detection units, and a battery module including the same.

Effects of the Invention

[0011] According to the above aspect of the present invention, electrical insulation between different lead portions can be ensured.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and the description will be omitted as appropriate.

[0014] In this specification, ordinal numbers such as "first", "second", "third", etc. are given for simply distinguishing the components with the same name, unless otherwise specified, and do not mean specific features of the components (for example, order or importance).

[0015] FIG. 1 is a perspective view of the battery module 50 according to the embodiment as seen from the front. FIG. 2 is a perspective view of the battery module 50 according to the embodiment as seen from the rear. FIG. 3 is a view of removing the container 20 from FIG. 1. FIG. 4 is a view of removing the container 20 from FIG. 2. FIG. 5 is a perspective view of the cell stack 10 according to the embodiment as seen from the front.

[0016] In FIGS. 1 to 5, the arrows indicating the first direction X, the second direction Y, and the third direction Z indicate that the direction from the base end to the tip of the arrow is the positive direction of the direction indicated by the arrow, and the direction from the tip to the base end of the arrow is the negative direction of the direction indicated by the arrow. The first direction X indicates a direction parallel to the horizontal direction perpendicular to the vertical direction. Specifically, the first direction X indicates the front-rear direction of the battery module 50. The positive direction of the first direction X is the direction from the front to the rear of the battery module 50. The negative direction of the first direction X is the direction from the rear to the front of the battery module 50. The second direction Y indicates a direction perpendicular to the vertical direction and the first direction X. The second direction Y indicates the left-right direction of the battery module 50. The positive direction of the second direction Y is the direction from the right to the left of the battery module 50 when viewed from the front of the battery module 50. The negative direction of the second direction Y is the direction from the left to the right of the battery module 50 when viewed from the front of the battery module 50. The third direction Z indicates a direction parallel to the vertical direction. The positive direction of the third direction Z is the direction from the bottom to the top of the battery module 50. The negative direction of the third direction Z is the direction from the top to the bottom of the battery module 50.

[0017] The relationships among the first direction X, the second direction Y, the third direction Z, the vertical direction, and the horizontal direction are not limited to the above-described examples. For example, the battery module 50 may be arranged such that the first direction X or the second direction Y is parallel to the vertical direction.

[0018] Hereinafter, unless otherwise specified, "right" and "left" respectively mean the right and left when viewed from the front of the battery module 50.

[0019] In this embodiment, the battery module 50 is mounted on a moving body such as an automobile. However, the use of the battery module 50 is not limited to this example.

[0020] The battery module 50 includes a cell stack 10, a container 20, a first voltage detection device 30A, and a second voltage detection device 30B. The first voltage detection device 30A has a first fuse device 40A. The second voltage detection device 30B has a second fuse device 40B. As will be described later with reference to FIG. 6, the first fuse device 40A has a fuse electrically connected to the terminal positive electrode lead 112T. The second fuse device 40B has a fuse electrically connected to the terminal negative electrode lead 114T.

[0021] As shown in FIG. 5, the cell stack 10 includes a plurality of cell groups 100G stacked in the second direction Y. Each cell group 100G includes a plurality of battery cells 100 stacked in the second direction Y. Each battery cell 100 includes an exterior member 102, a positive electrode lead 112, and a negative electrode lead 114.

[0022] In the present embodiment, each cell group 100G includes two battery cells 100. However, each cell group 100G may include three or more battery cells 100. In the cell stack 10, a plurality of battery cells 100 may be connected in series without a plurality of cell groups 100G being connected in series. In other words, the number of battery cells 100 included in the cell group 100G may be only one.

[0023] Each battery cell 100 is placed substantially vertically. The fact that the battery cell 100 is placed substantially vertically does not only mean that the battery cell 100 is placed strictly vertically. The fact that the battery cell 100 is placed substantially vertically means that the battery cell 100 may be inclined obliquely from the third direction Z as long as the operation of the battery module 50 is not hindered.

[0024] As shown in FIGS. 3 and 4, a plurality of adhesive members 104 are arranged on the upper surface of the cell laminate 10. Each adhesive member 104 is, for example, a cured body of a liquid resin. In the present embodiment, the plurality of adhesive members 104 are regularly arranged. Specifically, the plurality of adhesive members 104 extend in parallel with the second direction Y and are arranged side by side in parallel with the first direction X. An insulating sheet (not shown) is arranged above the plurality of adhesive members 104. Above the insulating sheet (not shown), a sixth cover member 260 described later is arranged. Note that the layout of the adhesive members 104 is not limited to the layout according to the present embodiment. For example, the adhesive members 104 may be provided over the entire upper surface of the cell laminate 10. Alternatively, the plurality of adhesive members 104 may be irregularly arranged, or may be arranged according to a rule different from the rule shown in FIGS. 3 and 4. Adhesive members are also arranged on the lower surface of the cell laminate 10 in the same manner as the upper surface of the cell laminate 10.

[0025] The exterior member 102 houses a positive electrode, a negative electrode, and a separator (not shown) together with an electrolytic solution (not shown). In one example, the positive electrode, the negative electrode, and the separator are laminated in the second direction Y within the exterior member 102. Alternatively, the positive electrode, the negative electrode, and the separator may be wound within the exterior member 102.

[0026] The positive electrode lead 112 is drawn out substantially in the horizontal direction from one of the front end and the rear end of the exterior member 102. The positive electrode lead 112 is electrically connected to the positive electrode within the exterior member 102. In one example, the positive electrode lead 112 is made of a metal such as aluminum. The fact that the positive electrode lead 112 is drawn out substantially in the horizontal direction does not only mean that the positive electrode lead 112 is strictly drawn out in the horizontal direction. The fact that the positive electrode lead 112 is drawn out substantially in the horizontal direction means that the positive electrode lead 112 may be drawn out in a direction deviated from the horizontal direction as long as the operation of the battery module 50 is not hindered.

[0027] The negative electrode lead 114 is drawn out substantially in the horizontal direction from the other of the front end and the rear end of the exterior member 102. The negative electrode lead 114 is electrically connected to the negative electrode in the exterior member 102. In one example, the negative electrode lead 114 is made of a metal different from the metal constituting the positive electrode lead 112, such as copper. The fact that the negative electrode lead 114 is drawn out substantially in the horizontal direction does not only mean that the negative electrode lead 114 is drawn out strictly in the horizontal direction. The fact that the negative electrode lead 114 is drawn out substantially in the horizontal direction means that the negative electrode lead 114 may be drawn out in a direction deviated from the horizontal direction as long as the operation of the battery module 50 is not hindered.

[0028] When a plurality of battery cells 100 are included in each cell group 100G, these plurality of battery cells 100 are connected in parallel. Specifically, the plurality of battery cells 100 included in each cell group 100G are stacked in the second direction Y. Also, the positive electrode leads 112 of the plurality of battery cells 100 included in each cell group 100G are bundled in the second direction Y and connected to each other. Also, the negative electrode leads 114 of the plurality of battery cells 100 included in each cell group 100G are bundled in the second direction Y and connected to each other. Adjacent battery cells 100 may be stacked via an adhesive member. Examples of the adhesive member include double-sided tape and those that cure a liquid resin.

[0029] A plurality of cell groups 100G are connected in series via lead portions 110. The lead portions 110 include a plurality of positive electrode leads 112 of one cell group 100G adjacent to another cell group 100G in the second direction Y, and a plurality of negative electrode leads 114 of the other cell group 100G adjacent to the cell group 100G in the second direction Y. The plurality of positive electrode leads 112 and negative electrode leads 114 included in the lead portion 110 are joined to each other by a joining method such as laser welding, ultrasonic bonding, resistance welding, or adhesion. When the material of the positive electrode lead 112 is different from the material of the negative electrode lead 114, among these joining methods, laser welding is preferable from the viewpoints of high joining reliability and reduction in the number of parts. The lead portion 110 is folded back between the cell groups 100G adjacent to each other in the second direction Y. As a result, in front of the cell laminate 10, the plurality of lead portions 110 are arranged in the second direction Y. Also, behind the cell laminate 10, the plurality of lead portions 110 are arranged in the second direction Y.

[0030] In the present embodiment, as shown in FIG. 3, at the joint portions of the plurality of positive electrode leads 112 and the plurality of negative electrode leads 114 of each lead portion 110 located in front of the cell laminate 10, the plurality of negative electrode leads 114 are located in front of the plurality of positive electrode leads 112. Also, as shown in FIG. 4, at the joint portions of the plurality of positive electrode leads 112 and the plurality of negative electrode leads 114 of each lead portion 110 located behind the cell laminate 10, the plurality of positive electrode leads 112 are located behind the plurality of negative electrode leads 114. When the plurality of positive electrode leads 112 are located in front of the plurality of negative electrode leads 114 in front of the cell laminate 10, it is preferable that the material of the first tip portion 314A described later is the same as the material of the positive electrode lead 112.

[0031] In the present embodiment, as shown in FIG. 3, a plurality of positive electrode leads 112 included in the cell group 100G at one end of a plurality of cell groups 100G connected in series are located on the right front side of the cell stack 10. Hereinafter, as necessary, a plurality of positive electrode leads 112 included in the cell group 100G at one end of a plurality of cell groups 100G connected in series are referred to as terminal positive electrode leads 112T. Further, as shown in FIG. 4, a plurality of negative electrode leads 114 included in the cell group 100G at the other end of a plurality of cell groups 100G connected in series are located on the left rear side of the cell stack 10. Hereinafter, as necessary, a plurality of negative electrode leads 114 included in the cell group 100G at the other end of a plurality of cell groups 100G connected in series are referred to as terminal negative electrode leads 114T.

[0032] The structure of the cell stack 10 is not limited to the structure according to the present embodiment. For example, the terminal negative electrode lead 114T may be located on the left front side instead of the left rear side of the cell stack 10. In this example, both the terminal positive electrode lead 112T and the terminal negative electrode lead 114T are located on the front side. Whether the terminal negative electrode lead 114T is located on the left front side or the left rear side of the cell stack 10 can be adjusted according to the number of cell groups 100G stacked in the second direction Y.

[0033] In the present embodiment, as shown in FIG. 3, the front surface of the joint portion of the positive electrode lead 112 and the negative electrode lead 114 of each lead portion 110 located in front of the cell stack 10 is substantially parallel to the direction perpendicular to the first direction X. The fact that the front surface of the joint portion is substantially parallel to the direction perpendicular to the first direction X does not only mean that the front surface of the joint portion is strictly parallel to the direction perpendicular to the first direction X. The fact that the front surface of the joint portion is substantially parallel to the direction perpendicular to the first direction X also means that the front surface of the joint portion is slightly deformed from the state parallel to the direction perpendicular to the first direction X within a range where the function of the lead portion 110 is not impaired. In the present embodiment, compared with the case where the front surface of the joint portion is curved, it is possible to facilitate the bonding of the first voltage detection unit 310A, which will be described later, to the front surface of the lead portion 110. In other examples different from the present embodiment, the front surface of the joint portion described above may be curved.

[0034] In the present embodiment, as shown in FIG. 4, the rear surface of the joint portion of the positive electrode lead 112 and the negative electrode lead 114 of each lead portion 110 located behind the cell stack 10 is substantially parallel to the direction perpendicular to the first direction X, in the same manner as the front surface of the joint portion of the positive electrode lead 112 and the negative electrode lead 114 of each lead portion 110 located in front of the cell stack 10.

[0035] The housing 20 houses the cell stack 10, the first voltage detection device 30A, and the second voltage detection device 30B. The housing 20 includes a first cover member 210, a second cover member 220, a third cover member 230, a fourth cover member 240, a fifth cover member 250, and a sixth cover member 260. In the present embodiment, the first cover member 210, the second cover member 220, the third cover member 230, the fourth cover member 240, the fifth cover member 250, and the sixth cover member 260 are made of, for example, a metal containing aluminum as a main component. However, the material constituting the first cover member 210, the second cover member 220, the third cover member 230, the fourth cover member 240, the fifth cover member 250, and the sixth cover member 260 is not limited to this example.

[0036] The first cover member 210 covers the front side of the cell stack 10 and the first voltage detection device 30A. The second cover member 220 covers the rear side of the cell stack 10 and the second voltage detection device 30B. The third cover member 230 covers the right side of the cell stack 10. The fourth cover member 240 covers the left side of the cell stack 10. The fifth cover member 250 covers the lower side of the cell stack 10. The sixth cover member 260 covers the upper side of the cell stack 10.

[0037] As shown in FIGS. 1 and 2, a “+” mark is attached to the upper surface of the sixth cover member 260 at the right front side. Also, a “-” mark is attached to the upper surface of the sixth cover member 260 at the left rear side. The “+” mark indicates that the terminal positive lead 112T shown in FIG. 3 is located at the position where the “+” mark is attached. The “-” mark indicates that the terminal negative lead 114T shown in FIG. 4 is located at the position where the “-” mark is attached. Therefore, even if the user of the battery module 50 can hardly see the cell stack 10 from the outside of the housing 20, the user can determine the positions of the terminal positive lead 112T and the terminal negative lead 114T from the “+” mark and the “-” mark.

[0038] The first voltage detection device 30A includes a first holder 300A, a plurality of first voltage detection units 310A, a plurality of first voltage detection lines 320A, and a first connector 330A.

[0039] The first holder 300A is provided in front of the cell stack 10. The first holder 300A is an insulator. As the insulator, a polypropylene-based resin or a resin having a hardness and insulation property equal to or higher than that thereof is used. The first holder 300A is attached to the housing 20 by mechanical joining such as snap fit or screws.

[0040] Each first voltage detection unit 310A includes a first base end portion 312A, a first tip end portion 314A, and a first connection portion 316A.

[0041] The first base end portion 312A is movably supported in the first direction X along a first support shaft 318A provided on the first holder 300A. Accordingly, each first voltage detection unit 310A is held by the first holder 300A. The first support shaft 318A penetrates a through hole provided in the first base end portion 312A in the first direction X. The diameter of the front end portion of the first support shaft 318A in a direction perpendicular to the first direction X is larger than the diameter of the through hole of the first base end portion 312A in the direction perpendicular to the first direction X. Therefore, the first base end portion 312A is suppressed from coming off the first support shaft 318A toward the front of the first support shaft 318A.

[0042] In the present embodiment, when viewed from the front of the cell stack 10, the first tip portion 314A is displaced horizontally and vertically with respect to the first base end portion 312A. Specifically, when viewed from the front of the cell stack 10, the first tip portion 314A is located on the lower right side of the first base end portion 312A. Accordingly, a gap is provided on the right side of the first base end portion 312A and above the first tip portion 314A, through which a part of the front surface of the lead portion 110 is exposed forward. Therefore, at least a part of a joint portion such as a laser welding portion between the positive electrode lead 112 and the negative electrode lead 114 can be provided in a region of the lead portion 110 where the gap overlaps with the first direction X. That is, the joint portion of the lead portion 110 need not overlap with the first tip portion 314A in the first direction X. Therefore, in the present embodiment, for example, compared with the case where the first tip portion 314A is located on the right side of the first base end portion 312A without being displaced downward with respect to the first base end portion 312A, the vertical length of the joint portion of the lead portion 110 can be increased. Therefore, in the present embodiment, compared with the above-described case, the connection between the positive electrode lead 112 and the negative electrode lead 114 in the lead portion 110 can be improved.

[0043] Also, in the present embodiment, the first tip portion 314A is displaced relative to the first base end portion 312A toward the side where the lead portion 110 is located. Therefore, in the present embodiment, compared with the case where the position of the first base end portion 312A in the first direction X and the position of the first tip portion 314A in the first direction X are aligned in the first direction X, the first tip portion 314A can be easily brought closer to the lead portion 110, and the first tip portion 314A can be easily connected to the lead portion 110. Also, in the present embodiment, compared with the above-described case, the movable range of the first base end portion 312A in the first direction X can be increased.

[0044] The first connection portion 316A protrudes downward from the first base end portion 312A. One end of the first voltage detection line 320A is connected to the first connection portion 316A. The first connection portion 316A may be integrally formed with the first base end portion 312A, for example. As shown in FIG. 6 to be described later, in the present embodiment, the first connection portion 316A has two first barrels 316aA that crimp one end of the first voltage detection line 320A. The two first barrels 316aA are arranged in the vertical direction. One end of the first voltage detection line 320A enters the internal space of the two first barrels 316aA substantially parallel to the vertical direction from below the two first barrels 316aA and is crimped by the two first barrels 316aA. Thereby, one end of the first voltage detection line 320A is fixed to the first connection portion 316A. However, the method of fixing one end of the first voltage detection line 320A to the first connection portion 316A is not limited to the method according to the present embodiment. For example, the number of the first barrels 316aA provided in each first connection portion 316A may be only one. Also, one end of the first voltage detection line 320A may be soldered to the first connection portion 316A.

[0045] The shape of the first voltage detection unit 310A is not limited to the shape according to the present embodiment as long as the first tip portion 314A does not overlap with the joint portion between the positive electrode lead 112 and the negative electrode lead 114 in the lead portion 110 in the first direction X. For example, when viewed from the front of the cell stack 10, the gap may not be provided on the right side of the first base end portion 312A and above the first tip portion 314A. Also, the position of the first base end portion 312A in the first direction X and the position of the first tip portion 314A in the first direction X may be aligned in the first direction X.

[0046] Each of the plurality of first voltage detection units 310A is connected to each of the plurality of lead portions 110 in front of the cell stack 10. Specifically, each first tip portion 314A is joined to each lead portion 110 in front of the cell stack 10 by a joining method such as laser welding. In the present embodiment, the rear surface of the first tip portion 314A is joined to the front surface of the joint portion between the positive electrode lead 112 and the negative electrode lead 114 of the lead portion 110. The first tip portion 314A is preferably made of the same material as the portion of the lead portion 110 that contacts the first tip portion 314A. In the present embodiment, the first tip portion 314A is in contact with the negative electrode lead 114. In this example, it becomes easier to join the first tip portion 314A to the negative electrode lead 114 as compared with the case where the first tip portion 314A is made of a material different from that of the negative electrode lead 114. In other examples, the first tip portion 314A may be made of a material different from that of the portion of the lead portion 110 that contacts the first tip portion 314A.

[0047] Each of the plurality of first voltage detection lines 320A electrically connects each of the plurality of first voltage detection units 310A to the first connector 330A. As described above, one end of each first voltage detection line 320A is connected to the first connection portion 316A. The other end of each first voltage detection line 320A is connected to the first connector 330A. In the present embodiment, a part of each first voltage detection line 320A is drawn out from the first connection portion 316A to the space below the first frame 340A via a notch 350A provided in the first frame 340A described later. The notch 350A is provided at the corner between a second edge portion 344A and a third edge portion 346A of the first frame 340A described later. Another part of each first voltage detection line 320A passes through the space between the adjacent first frames 340A in a region shifted to the right from the center of the first holder 300A and is drawn out from the space below the plurality of first frames 340A to the first connector 330A located above the plurality of first frames 340A. The position of the first voltage detection unit 310A, the routing of the first voltage detection line 320A, the position of the notch 350A, and the position of the first connector 330A are not limited to the examples according to the present embodiment.

[0048] In the present embodiment, at least a part of the region of the first voltage detection line 320A located between the first connection portion 316A and the notch 350A has flexibility. When the first base end portion 312A is moved in the first direction X along the first support shaft 318A, the first voltage detection line 320A may contact the first holder 300A or the first frame 340A in the vicinity of the notch 350A. Even in such a case, the first base end portion 312A can be moved in the first direction X along the first support shaft 318A by the bending of at least the above-described part of the first voltage detection line 320A.

[0049] The first holder 300A has a plurality of first frames 340A. The first frame 340A is an insulator. As the insulator, a polypropylene-based resin or a resin having a hardness and insulation property equal to or higher than that thereof is used. Each of the plurality of first frames 340A surrounds each of the plurality of lead portions 110 and each of the plurality of first voltage detection portions 310A. Therefore, the lead portion 110 and the first voltage detection portion 310A can be protected by the first frame 340A from an external impact. Each first frame 340A does not have to be located in the entire area surrounding each lead portion 110 and each first voltage detection portion 310A. Each first frame 340A may be located in at least a part of the area surrounding each lead portion 110 and each first voltage detection portion 310A. The first holder 300A may be composed of a single member, or may be composed of a plurality of members combined with each other.

[0050] Each first frame 340A includes a first edge portion 342A, a second edge portion 344A, a third edge portion 346A, and a fourth edge portion 348A. The first edge portion 342A extends vertically on the right side of the lead portion 110 and the first voltage detection portion 310A surrounded by each first frame 340A. The second edge portion 344A extends vertically on the left side of the lead portion 110 and the first voltage detection portion 310A surrounded by each first frame 340A. The third edge portion 346A extends horizontally on the lower side of the lead portion 110 and the first voltage detection portion 310A surrounded by each first frame 340A. The fourth edge portion 348A extends horizontally on the upper side of the lead portion 110 and the first voltage detection portion 310A surrounded by each first frame 340A.

[0051] The shape of the first frame 340A is not limited to the shape according to the present embodiment. For example, the first frame 340A does not have to have one of the first edge portion 342A and the second edge portion 344A. Further, the first frame 340A does not have to have at least one of the third edge portion 346A and the fourth edge portion 348A.

[0052] In this embodiment, at least a part of the insulator constituting each first frame 340A is located between a first voltage detection unit 310A surrounded by each first frame 340A and a lead unit 110 different from the lead unit 110 connected to the first voltage detection unit 310A. Therefore, in this embodiment, electrical insulation can be ensured between the first voltage detection unit 310A surrounded by each first frame 340A and the lead unit 110 different from the lead unit 110 connected to the first voltage detection unit 310A.

[0053] Specifically, except for the first frame 340A located at the rightmost end, at least a part of the insulator constituting the first edge portion 342A is located between the first voltage detection unit 310A located on the left side of the first edge portion 342A and the lead unit 110 located on the right side of the first edge portion 342A. Therefore, compared with the case where the first edge portion 342A is not provided, electrical insulation can be ensured between the first voltage detection unit 310A located on the left side of the first edge portion 342A and the lead unit 110 located on the right side of the first edge portion 342A.

[0054] Also, except for the first frame 340A located at the leftmost end, at least a part of the insulator constituting the second edge portion 344A is located between the first voltage detection unit 310A located on the right side of the second edge portion 344A and the lead unit 110 located on the left side of the second edge portion 344A. Therefore, compared with the case where the second edge portion 344A is not provided, electrical insulation can be ensured between the first voltage detection unit 310A located on the right side of the second edge portion 344A and the lead unit 110 located on the left side of the second edge portion 344A.

[0055] In the present embodiment, at least a part of the insulator constituting each first frame 340A is located between different lead portions 110. Specifically, at least a part of the insulator constituting each first frame 340A is located between adjacent lead portions 110. Therefore, compared with the case where at least a part of the insulator constituting each first frame 340A is not located between different lead portions 110, electrical insulation between different lead portions 110 can be ensured.

[0056] Specifically, except for the first frame 340A located at the rightmost end, at least a part of the insulator constituting the first edge portion 342A is located between the lead portion 110 located on the left side of the first edge portion 342A and the lead portion 110 located on the right side of the first edge portion 342A. Therefore, compared with the case where the first edge portion 342A is not provided, electrical insulation between the lead portion 110 located on the left side of the first edge portion 342A and the lead portion 110 located on the right side of the first edge portion 342A can be ensured.

[0057] Also, except for the first frame 340A located at the leftmost end, at least a part of the insulator constituting the second edge portion 344A is located between the lead portion 110 located on the right side of the second edge portion 344A and the lead portion 110 located on the left side of the second edge portion 344A. Therefore, compared with the case where the second edge portion 344A is not provided, electrical insulation between the lead portion 110 located on the right side of the second edge portion 344A and the lead portion 110 located on the left side of the second edge portion 344A can be ensured.

[0058] Note that an insulating protrusion protruding toward the positive side in the first direction X may be provided on the surface of the first frame 340A on the positive side in the first direction X. At least a part of this protrusion is located between the lead portions 110 adjacent to each other in the second direction Y. For example, the protrusion is provided on the positive side in the first direction X of the first edge portion 342A of the left first frame 340A among the first frames 340A adjacent to each other in the second direction Y, and on the positive side in the first direction X of the second edge portion 344A of the right first frame 340A among the first frames 340A adjacent to each other in the second direction Y. In this example, when the lead portions 110 adjacent to each other in the second direction Y are displaced in the second direction Y due to factors such as an external impact, the lead portions 110 hit the protrusion. Therefore, the collision between the lead portions 110 adjacent to each other in the second direction Y can be suppressed. The length of the protrusion is not particularly limited, but for example, it can be a length for suppressing the collision between the lead portions 110 adjacent to each other in the second direction Y. Further, the position where the protrusion is provided is not limited to the above-described example.

[0059] In the present embodiment, at least a part of the insulator constituting each first frame 340A is located between at least one lead portion 110 and at least a part of the housing 20 having conductivity. Therefore, in the present embodiment, electrical insulation between at least one lead portion 110 and at least a part of the housing 20 having conductivity can be ensured.

[0060] Specifically, at least a part of the third edge portion 346A is located below the lead portion 110 surrounded by each first frame 340A. In the present embodiment, the front end portion of the fifth cover member 250 is located below the lower end portion of the lead portion 110. When the fifth cover member 250 has conductivity, if the lower end portion of the lead portion 110 contacts the front end portion of the fifth cover member 250, there is a risk of a short circuit between the lead portion 110 and the fifth cover member 250. In contrast, in the present embodiment, at least a part of the insulator constituting the third edge portion 346A is located between the lower end portion of the lead portion 110 and the front end portion of the fifth cover member 250. Therefore, compared with the case where the third edge portion 346A is not provided, a short circuit between the lead portion 110 and the fifth cover member 250 can be suppressed.

[0061] In the above-described example, it has been explained that electrical insulation between the lower end portion of the lead portion 110 and the front end portion of the fifth cover member 250 is ensured by the third edge portion 346A. However, ensuring electrical insulation between the lead portion 110 and the housing 20 by the first frame 340A is not limited to the above-described example. For example, electrical insulation between the upper end portion of the lead portion 110 and the front end portion of the sixth cover member 260 can be ensured by the fourth edge portion 348A. Also, electrical insulation between the right end portion of the lead portion 110 located at the rightmost end among the plurality of lead portions 110 and the front end portion of the third cover member 230 can be ensured by the first edge portion 342A of the first frame 340A located at the rightmost end among the plurality of first frames 340A. Further, electrical insulation between the left end portion of the lead portion 110 located at the leftmost end among the plurality of lead portions 110 and the front end portion of the fourth cover member 240 can be ensured by the second edge portion 344A of the first frame 340A located at the leftmost end among the plurality of first frames 340A.

[0062] In this embodiment, between the lead portions 110 adjacent to each other in the second direction Y, there are a second edge portion 344A of the first frame 340A surrounding the right lead portion 110 among the lead portions 110 adjacent to each other in the second direction Y, and a first edge portion 342A of the first frame 340A surrounding the left lead portion 110 among the lead portions 110 adjacent to each other in the second direction Y. Therefore, the distance in the second direction Y between the adjacent lead portions 110 in the second direction Y needs to be larger than the distance in the second direction Y between the above-described second edge portion 344A and the above-described first edge portion 342A located between the adjacent lead portions 110 in the second direction Y. The distance in the second direction Y between the adjacent lead portions 110 in the second direction Y becomes larger as the number of battery cells 100 included in the cell group 100G increases. Therefore, it is easier to increase the distance in the second direction Y between the adjacent lead portions 110 in the second direction Y when the number of battery cells 100 included in the cell group 100G is plural than when the number of battery cells 100 included in the cell group 100G is only one.

[0063] Similar to the first voltage detection device 30A, the second voltage detection device 30B has a second holder 300B, a plurality of second voltage detection units 310B, a plurality of second voltage detection lines 320B, and a second connector 330B.

[0064] The second holder 300B is provided behind the cell stack 10. Each of the plurality of second voltage detection units 310B is connected to each of the plurality of lead portions 110 behind the cell stack 10. In this embodiment, the surface on the negative direction side in the first direction X of each second voltage detection unit 310B is joined to the surface on the positive direction side in the first direction X of the joint portion of the positive electrode lead 112 and the negative electrode lead 114 of the lead portion 110. Each of the plurality of second voltage detection lines 320B electrically connects each of the plurality of second voltage detection units 310B to the second connector 330B. The second holder 300B is provided with a plurality of second frames 340B. Each of the plurality of second frames 340B surrounds each of the plurality of lead portions 110 provided behind the cell stack 10 and each of the plurality of second voltage detection units 310B, in the same manner as the plurality of first frames 340A.

[0065] FIG. 6 is an enlarged view of the position where the first fuse device 40A is provided in the first voltage detection device 30A according to the embodiment.

[0066] The first fuse device 40A includes a first base 302A, a first conductor 400A, a first fixture 432A, a second fixture 434A, and a first wiring 440A.

[0067] The first base 302A includes the right end portion of the first holder 300A. In the present embodiment, the first base 302A includes the two rightmost first frames 340A among the plurality of first frames 340A.

[0068] The first conductor 400A is provided on the first base 302A. The first conductor 400A is made of, for example, metal. The first conductor 400A functions as a bus bar electrically connected to the terminal positive electrode lead 112T.

[0069] The first conductor 400A includes a plurality of extending bodies extending in different directions. At least a part of at least one of the plurality of extending bodies is held by the first base 302A.

[0070] Specifically, the first conductor 400A includes a first extending body 410A extending in the horizontal direction and a second extending body 420A extending in the vertical direction. The second extending body 420A extends downward from the right end portion of the first extending body 410A. The first extending body 410A and the second extending body 420A are integrally formed. However, the first conductor 400A may be formed by bonding, for example, the metal that becomes the first extending body 410A and the metal that becomes the second extending body 420A. However, the forming method of the first conductor 400A is not limited to this example. Also, the shape of the first conductor 400A is not limited to the shape according to the present embodiment. For example, the first conductor 400A may not include the second extending body 420A.

[0071] The first extension body 410A includes a first wide portion 412A, a narrow portion 414A, and a second wide portion 416A. The left end of the narrow portion 414A is connected to the right end of the first wide portion 412A. The right end of the narrow portion 414A is connected to the left end of the second wide portion 416A.

[0072] The first wide portion 412A functions as a terminal for electrically connecting to another battery module (not shown). A fastening hole 450A is provided at the left end portion of the first wide portion 412A. In the fastening hole 450A, for example, a fixture (not shown) for fixing a bus bar (not shown) electrically connected to another battery module is fixed. In the present embodiment, the peripheral portion of the fastening hole 450A of the first wide portion 412A is at a position higher than that of the narrow portion 414A. However, the peripheral portion of the fastening hole 450A of the first wide portion 412A may be at the same height as the narrow portion 414A.

[0073] The narrow portion 414A functions as a fuse. The width of the narrow portion 414A in the first direction X is narrower than either the width of the first wide portion 412A in the first direction X or the width of the second wide portion 416A in the first direction X. For this reason, the cross-sectional area perpendicular to the second direction Y of the narrow portion 414A is smaller than either the cross-sectional area perpendicular to the second direction Y of the first wide portion 412A or the cross-sectional area perpendicular to the second direction Y of the second wide portion 416A. Therefore, when an overcurrent flows through the first conductor 400A, the narrow portion 414A is more likely to melt than the first wide portion 412A and the second wide portion 416A.

[0074] In the present embodiment, the narrow portion 414A is attached to the first holder 300A. Therefore, compared with the case where a structure for holding the fuse is provided separately from the first holder 300A, the first voltage detection unit 310A and the fuse can be provided spatially efficiently.

[0075] Furthermore, in the present embodiment, the battery module 50 can be miniaturized as compared with the case where a tubular fuse is used as the fuse. Specifically, when a tubular fuse is used, the size of the tubular fuse increases as the energy of the battery module 50 increases. Therefore, in the battery module 50 with relatively high energy, the space for providing the tubular fuse becomes relatively large. On the other hand, when a part of the first conductor 400A functions as a fuse, the space for providing the fuse can be reduced as compared with the case where a tubular fuse is used.

[0076] In the present embodiment, the narrow portion 414A extends in the same direction as the extending direction of the first wide portion 412A. That is, the first wide portion 412A and the narrow portion 414A extend in the second direction Y. If the narrow portion 414A is provided on the second extending body 420A and extends in a direction orthogonal to the extending direction of the first wide portion 412A, it may be difficult to join the narrow portion 414A provided on the second extending body 420A to the terminal positive electrode lead 112T. In contrast, in the present embodiment, it is not necessary to provide the narrow portion 414A on the second extending body 420A. Therefore, in the present embodiment, the length in the third direction Z of the joint portion between the second extending body 420A and the terminal positive electrode lead 112T can be increased as compared with the above-described case. Also, in the present embodiment, the length of the narrow portion 414A in the second direction Y can be more easily adjusted as compared with the above-described case. Furthermore, in the present embodiment, the narrow portion 414A and the terminal positive electrode lead 112T can be provided farther apart as compared with the above-described case. Therefore, in the present embodiment, the influence of the heat generation of the narrow portion 414A on the terminal positive electrode lead 112T can be suppressed as compared with the above-described case.

[0077] A first space 402A that defines the narrow portion 414A is provided in front of the narrow portion 414A in the first extending body 410A. In the present embodiment, the first space 402A is formed by punching out a front portion of the portion that becomes the narrow portion 414A among the conductors constituting the first extending body 410A by press working.

[0078] Behind the narrow portion 414A of the first extending body 410A, there is no space defining the narrow portion 414A. However, the method of forming the narrow portion 414A is not limited to the method according to this embodiment. For example, the first space 402A may be provided behind the narrow portion 414A. Alternatively, the first space 402A may be provided on both the front and rear sides of the narrow portion 414A. Further, the first space 402A may be formed by a through-hole penetrating the first extending body 410A in the vertical direction. In this case, the portions on both sides of the first space 402A in the first direction X of the first extending body 410A become the narrow portions 414A functioning as fuses.

[0079] When forming the narrow portion 414A by pressing, as in this embodiment, it is preferable that the space defining the narrow portion 414A is provided only on one of the two sides of the first extending body 410A in the first direction X. In this case, it is not necessary to punch out the rear portion of the portion that becomes the narrow portion 414A among the conductors constituting the first extending body 410A by pressing. Compare this embodiment with the case where both the front portion and the rear portion of the portion that becomes the narrow portion 414A among the conductors constituting the first extending body 410A are punched out by pressing. In the above-described case, compared with this embodiment, since it is necessary to punch out the front portion and the rear portion of the portion that becomes the narrow portion 414A simultaneously or individually, the mechanical load applied to the narrowest narrow portion 414A in the first extending body 410A during pressing increases. Therefore, in the above-described case, compared with this embodiment, from the viewpoint of suppressing the breakage of the narrow portion 414A, it is necessary to widen the width of the narrow portion 414A in the first direction X. On the other hand, in this embodiment, compared with the above-described case, the width of the narrow portion 414A in the first direction X can be made narrower, and the degree of freedom in the dimensions of the narrow portion 414A can be increased.

[0080] Note that the method of forming the narrow portion 414A is not limited to press working. The narrow portion 414A may be formed, for example, by laser processing. When the narrow portion 414A is formed by laser processing, the space defining the narrow portion 414A may be provided on only one of both sides in the first direction X of the first extending body 410A, or may be provided on both sides in the first direction X of the first extending body 410A.

[0081] A second space 304A is provided below the narrow portion 414A. The second space 304A is defined by a recess provided on the upper surface of the first base 302A on which the first extending body 410A is placed. In the present embodiment, when an overcurrent flows through the first conductor 400A and the narrow portion 414A melts, the melted narrow portion 414A can fall toward the second space 304A. Therefore, according to the present embodiment, the accuracy of fusing the narrow portion 414A can be increased as compared with the case where the lower surface of the narrow portion 414A is in contact with the upper surface of the first base 302A.

[0082] In the present embodiment, at least a part of the narrow portion 414A is located above at least one of the positive electrode lead 112 and the negative electrode lead 114. Further, at least a part of the first base 302A is located between at least one of the positive electrode lead 112 and the negative electrode lead 114 and at least a part of the narrow portion 414A in the third direction Z. Specifically, the portion defining the bottom of the recess in the first base 302A is located between at least one of the positive electrode lead 112 and the negative electrode lead 114 and at least a part of the narrow portion 414A in the third direction Z. Therefore, it is possible to prevent the melted narrow portion 414A from contacting the positive electrode lead 112 or the negative electrode lead 114 located below the narrow portion 414A.

[0083] A portion located above at least one of the positive electrode lead 112 and the negative electrode lead 114 of the first base 302A may have heat resistance. For example, a heat-resistant layer may be provided on the bottom surface of the concave portion of the first base 302A. The heat-resistant layer may be a metal, or may be an inorganic material such as ceramic or vitreous material. By providing the heat-resistant layer, it is possible to more reliably prevent the melted narrow portion 414A from melting the main body portion of the first base 302A and contacting the positive electrode lead 112, the negative electrode lead 114, or the first wiring 440A.

[0084] The first wide portion 412A is fixed to the first base 302A by the first fixture 432A. In the present embodiment, the first fixture 432A is a screw that penetrates the first wide portion 412A in the vertical direction and is inserted into a portion of the first base 302A located below the first wide portion 412A. The first wide portion 412A is provided with a through hole through which the shaft portion of the first fixture 432A can be inserted in the vertical direction. The first fixture 432A may be a fixture other than a screw, such as a screw, a bolt, or the like.

[0085] The second wide portion 416A is fixed to the first base 302A by the second fixture 434A. In the present embodiment, the second fixture 434A is a screw that penetrates the second wide portion 416A in the vertical direction and is inserted into a portion of the first base 302A located below the second wide portion 416A. The second wide portion 416A is provided with a through hole through which the shaft portion of the second fixture 434A can be inserted in the vertical direction. The second fixture 434A may be a fixture other than a screw, such as a screw, a bolt, or the like.

[0086] In the present embodiment, fixtures such as the first fixture 432A and the second fixture 434A are detachable from the first conductor 400A. Therefore, when it is necessary to replace the first conductor 400A due to the narrow portion 414A being blown, etc., the first conductor 400A can be replaced with a new first conductor 400A by removing the fixtures such as the first fixture 432A and the second fixture 434A.

[0087] The method of fixing the first conductor 400A to the first base 302A is not limited to the above-described example. For example, at least a part of the first conductor 400A may be joined to at least a part of the first base 302A through a mechanical joining such as a snap fit.

[0088] In the present embodiment, both the first wide portion 412A and the second wide portion 416A are fixed to the first base 302A by the first fixture 432A and the second fixture 434A. In this case, compared with the case where at least one of the first wide portion 412A and the second wide portion 416A is not fixed to the first base 302A, the force for breaking the narrow portion 414A can be suppressed from being applied to the narrow portion 414A. The force for breaking the narrow portion 414A occurs, for example, when a bus bar (not shown) is attached to the first wide portion 412A in order to electrically connect the battery module 50 to another battery module (not shown), and a fixture (not shown) is fixed to the fastening hole 450A. This is because the fastening hole 450A and the narrow portion 414A are located in substantially the same plane perpendicular to the third direction Z.

[0089] The first fixture 432A and the second fixture 434A are preferably arranged at positions close to the narrow portion 414A. For example, the first fixture 432A and the second fixture 434A are preferably provided at positions facing each other through the first space 402A.

[0090] In the present embodiment, at least a part of the first wiring 440A passes through the first space 402A. In this case, the first wiring 440A can be spatially and efficiently routed as compared with the case where the first wiring 440A passes through a region different from the first space 402A.

[0091] Also, in the present embodiment, at least a part of the first wiring 440A passes through a portion horizontally shifted from a portion located below the narrow portion 414A of the first base 302A. In the present embodiment, a through-hole for passing the first wiring 440A is provided in the bottom surface of the recess that defines the second space 304A in the first base 302A. The through-hole is located on the negative direction side of the first direction X from the region directly below the narrow portion 414A. Therefore, it is possible to make it difficult for the narrow portion 414A that has melted and dropped into the second space 304A to contact the first wiring 440A.

[0092] The first wiring 440A has one end connected to the second wide portion 416A and the other end connected to the first connector 330A shown in FIG. 3. A part of the first wiring 440A is drawn downward from one end connected to the second wide portion 416A of the first wiring 440A and passes through the first space 402A and the second space 304A. Another part of the first wiring 440A passes through a region between the part of the first base 302A located below the second space 304A and the rightmost two first frames 340A and is drawn out to the space below the plurality of first frames 340A. Still another part of the first wiring 440A passes through the space between the adjacent first frames 340A in a region shifted to the right from the center of the first holder 300A and is drawn from the space below the plurality of first frames 340A to the first connector 330A located above the plurality of first frames 340A. The routing of the first wiring 440A is not limited to the example according to the present embodiment.

[0093] In the present embodiment, one end of the first wiring 440A connected to the second wide portion 416A is fixed to the second wide portion 416A by the second fixture 434A. In the present embodiment, when the one end of the first wiring 440A is fixed to the second wide portion 416A by, for example, solder, the attachment and detachment of the first wiring 440A when the narrow portion 414A is fused is facilitated as compared with this case. A connection component such as a crimp terminal may be provided at the one end of the first wiring 440A. In this case, by fixing the connection component by the second fixture 434A, the one end of the first wiring 440A can be fixed to the second wide portion 416A. However, the method of connecting the one end of the first wiring 440A to the second wide portion 416A is not limited to this example.

[0094] Further, in the present embodiment, the second fixture 434A fixes both the second wide portion 416A and one end of the first wiring 440A connected to the second wide portion 416A to the first base 302A. In this case, the number of components can be reduced as compared with the case where a fixture for fixing the second wide portion 416A to the first base 302A and a fixture for fixing the one end of the first wiring 440A to the first base 302A are provided separately. In another example different from the present embodiment, a fixture for fixing the second wide portion 416A to the first base 302A and a fixture for fixing the one end of the first wiring 440A to the first base 302A may be provided separately.

[0095] In the second wide portion 416A, the portion where the second fixture 434A is provided functions as a voltage detection unit that detects the voltage of the terminal positive electrode lead 112T. That is, the terminal positive electrode lead 112T is the voltage detection target of the portion where the second fixture 434A is provided in the second wide portion 416A. The first wiring 440A functions as a voltage detection line electrically connected to the voltage detection unit. In the present embodiment, one end of the first wiring 440A fixed by the second fixture 434A is electrically connected to the second wide portion 416A. In this case, compared with the case where the first wiring 440A is electrically connected to the first wide portion 412A, the influence of the voltage drop in the narrow portion 414A can be suppressed, and the voltage of the terminal positive electrode lead 112T can be detected. Therefore, the voltage of the terminal positive electrode lead 112T can be detected more accurately.

[0096] In FIGS. 3 and 6, the second extension body 420A is electrically connected to the terminal positive electrode lead 112T. In the present embodiment, the right side surface of the second extension body 420A and the left side surface of the terminal positive electrode lead 112T are joined to each other by a joining method such as laser welding. Note that the second extension body 420A may not be provided. When the second extension body 420A is not provided, it is also possible to electrically connect the terminal positive electrode lead 112T and the first extension body 410A via an L-shaped bus bar (not shown).

[0097] At least a portion of the second extension body 420A is held by at least a portion of the first base 302A. In the present embodiment, the upper end of the second extension body 420A is held by both side surfaces in the second direction Y of the through hole through which the upper end of the second extension body 420A penetrates in the first base 302A. Also, the lower end of the second extension body 420A is held by both side surfaces in the second direction Y of the hole into which the lower end of the second extension body 420A is inserted in the first base 302A. In the present embodiment, it is preferable because it is possible to suppress the application of a force that rotates the narrow portion 414A in a direction perpendicular to the vertical direction as compared with the case where the second extension body 420A is not held by the first base 302A. Therefore, breakage of the narrow portion 414A can be further suppressed as compared with the case where the second extension body 420A is not held by the first base 302A.

[0098] As described above, embodiments of the present invention have been described with reference to the drawings, but these are examples of the present invention, and various configurations other than the above can also be adopted.

[0099] For example, the first fuse device 40A according to the embodiment is electrically connected to the battery cell 100. However, the first fuse device 40A may be electrically connected to an electronic device different from the battery cell 100. The same applies to the second fuse device 40B. Hereinafter, examples of reference forms will be appended. 1. A plurality of voltage detection units connected to a plurality of lead portions of a plurality of battery cells, A holding body that holds the plurality of voltage detection units, An insulator provided on the holding body and at least a portion of which is located between different lead portions, A voltage detection device comprising: 2. The voltage detection device according to 1., wherein at least another portion of the insulator is located between the lead portion and at least a portion having conductivity among the housing bodies that house the plurality of battery cells. 3. The voltage detection device according to 1. or 2., wherein the insulator is located at least in a portion of the region surrounding the voltage detection unit. 4. The voltage detection device according to any one of 1. to 3., wherein the lead portion includes a plurality of positive electrodes connected to each other and a plurality of negative electrodes connected to each other. 5. The voltage detection device according to any one of 1. to 4., and a plurality of battery cells having the plurality of lead portions electrically connected to the plurality of voltage detection portions, A battery module comprising:

Explanation of symbols

[0100] 10 Cell stack 20 Container 30A First voltage detection device 30B Second voltage detection device 40A First fuse device 40B Second fuse device 50 Battery module 100 Battery cell 100G Cell group 102 Exterior material 104 Adhesive member 110 Lead portion 112 Positive electrode lead 112T Terminal positive electrode lead 114 Negative electrode lead 114T Terminal negative electrode lead 210 First cover member 220 Second cover member 230 Third cover member 240 Fourth cover member 250 Fifth cover member 260 Sixth cover member 300A First holder 300B Second holder 302A First base 304A Second space 310A First voltage detection portion 310B Second voltage detection portion 312A First base end portion 314A First tip portion 316A First connection portion 316aA First barrel 318A First support shaft 320A First voltage detection line 320B Second voltage detection line 330A First connector 330B Second connector 340A First frame 340B Second frame 342A First edge 344A Second edge 346A Third edge 348A Fourth edge 350A Notch 400A First conductor 402A First space 410A First extending body 412A First wide portion 414A Narrow portion 416A Second wide portion 420A Second extending body 432A First fixture 434A Second fixture 440A First wiring 450A Fastening hole X First direction Y Second direction Z Third direction

Claims

1. A plurality of battery cells each having a positive electrode lead and a negative electrode lead, A voltage detection device located on one side of the plurality of battery cells, Comprising, At least one of the positive electrode leads of at least one battery cell and at least one of the negative electrode leads of at least one other battery cell are connected to each other on the one side to form a lead portion, The voltage detection device has a voltage detection portion connected to the lead portion, a holder for holding the voltage detection portion, and an insulator provided on the holder, At least a part of the insulator is located between the lead portions, a battery module.

2. The holder has a frame surrounding the lead portion and the voltage detection portion, The frame includes the insulator, the battery module according to claim 1.

3. The at least one positive electrode lead and the at least one negative electrode lead forming the lead portion are connected to each other by laser welding, the battery module according to claim 1 or 2.

4. The lead portion and the voltage detection portion are connected to each other by laser welding, the battery module according to any one of claims 1 to 3.

5. A plurality of the positive electrode leads of some of the plurality of battery cells and a plurality of the negative electrode leads of some other of the plurality of battery cells are connected to each other on the one side to form the lead portion, the battery module according to any one of claims 1 to 4.

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