Battery module

Abstract

A battery module (1) includes: a plurality of battery cells (10) each having a battery element (11), a lid material (12) which at least partially covers the battery element (11), and an exterior film (14) which is wound around the battery element (11) and the lid material (12) and includes a conductor; a connection bus bar (20) which electrically connects the battery cells (10) to each other; and a first partition member (34) and a second partition member (35) which partition the conductor included in the exterior film (14) and the connection bus bar (20).

Description

Battery module

[0001] The present invention relates to a battery module.

[0002] In recent years, various battery modules have been developed. A battery module includes a plurality of battery cells.

[0003] Patent Document 1 describes a battery pack. The battery pack includes a plurality of unit cells, a holder member, and a substrate. The holder member is located between the plurality of unit cells and the substrate. The holder member defines an insertion hole through which a tab of a unit cell is inserted. The tabs of the unit cells overlap each other on the substrate and are connected to each other.

[0004] Japanese Unexamined Patent Publication No. 2012-212595

[0005] Battery cells may be electrically connected to each other via a bus bar. A battery cell may include a battery element, a lid member that at least partially covers the battery element, and an exterior material wound around the battery element and the lid member. The exterior material may be formed of a laminate film including a conductor such as aluminum foil. The conductor included in the exterior material may be exposed from an end portion of the exterior material. Therefore, it may be necessary to ensure electrical insulation between the conductor included in the exterior material and the bus bar.

[0006] An object of the present invention is to ensure electrical insulation between a conductor included in an exterior material and a bus bar. Other objects of the present invention will become apparent from the description of the present specification.

[0007] One aspect of the present invention is as follows: 1. A battery module comprising: a plurality of battery cells, each having a battery element, a cover material that at least partially covers the battery element, and an outer material that is wrapped around the battery element and the cover material and includes a conductor; bus bars that electrically connect the battery cells to each other; and a partition member that separates the conductor and the bus bars. 2. The battery module according to 1, wherein the partition member has a first portion that covers the conductor and a second portion that extends from the first portion. 3. The battery module according to 1, wherein each of the plurality of battery cells further has terminals electrically connected to the battery element, and the partition member is at least partially located between the terminals that are electrically connected via the bus bars. 4. The battery module according to 3, wherein the plurality of battery cells are stacked in a first direction, the terminals have ends located on one side of a second direction perpendicular to the first direction, and the partition member has ends located on the side of the ends of the terminals. 5. The battery module according to 4., wherein the busbar has a first region located on one side of the end of the partition member, a second region located on one side of the end of the terminal, and a third region extending from the first region to the second region toward the side where the plurality of battery cells are located. 6. The battery module according to 3., wherein the exterior material has an end located between the terminals that are electrically connected via the busbar, and at least a portion of the partition member separates the terminals from the end of the exterior material. 7. The battery module according to 1., wherein the partition member is at least partially located between adjacent busbars. 8. The battery module according to 7., wherein the plurality of battery cells are stacked in a first direction, the busbar has an end located on one side in a second direction perpendicular to the first direction, and the partition member has an end located on one side of the end of the busbar.9. The battery module according to 1., wherein the plurality of battery cells are stacked in a first direction, each of the plurality of battery cells further has terminals electrically connected to the battery element, and the partition member includes a first partition member at least partially located between the terminals electrically connected via the busbars, and a second partition member at least partially located between adjacent busbars, and at least a portion of the first partition member and at least a portion of the busbars overlap in a second direction perpendicular to the first direction, and the dimension of the second partition member in the second direction is greater than the sum of the dimension of the at least portion of the first partition member and the at least portion of the busbars in the second direction. 10. The battery module according to any one of 1. to 9., further comprising a protector that at least partially covers the plurality of battery cells, the protector having the partition member.

[0008] According to the above embodiment of the present invention, electrical insulation can be ensured between the conductor contained in the exterior material and the busbar.

[0009] This is a perspective view of the battery module according to the embodiment. This is a perspective view of the battery module with the protector removed. This is a cross-sectional view along the virtual plane S in Figure 1. This is an enlarged view of the region α shown in Figure 3.

[0010] Embodiments of the present invention will be described below with reference to the drawings. In all drawings, similar components are denoted by the same reference numerals, and their descriptions are omitted where appropriate.

[0011] Figure 1 is a perspective view of the battery module 1 according to an embodiment. Figure 2 is a perspective view of the battery module 1 with the protector 30 removed. Figure 3 is a cross-sectional view along the virtual plane S in Figure 1. Figure 4 is an enlarged view of the region α shown in Figure 3.

[0012] Each figure shows the X-axis, Y-axis, and Z-axis for explanatory purposes, indicating the X, Y, and Z directions, respectively. In Figures 3 and 4, the white circle with a black dot indicating the Z-axis indicates that the Z-axis arrow is pointing towards the viewer on the page. The X-direction indicates the front-to-back direction of the battery module 1. The Y-direction is one of the directions perpendicular to the X-direction. The Y-direction indicates the left-to-right direction of the battery module 1. The Z-direction is perpendicular to both the X and Y directions. The Z-direction indicates the up-to-down direction of the battery module 1. The directions indicated by the tip of the X-axis arrow, the direction indicated by the tip of the Y-axis arrow, and the direction indicated by the tip of the Z-axis arrow indicate the rear, right, and up directions of the battery module 1, respectively. The relationship between the X-direction, Y-direction, and Z-direction and the front-to-back, left-to-right, and up-to-down directions of the battery module 1 is not limited to this example.

[0013] Unless otherwise specified, the +X side or +X refers to the side indicated by the tip of the X-axis arrow, and the -X side or -X refers to the opposite side of the side indicated by the tip of the X-axis arrow. Unless otherwise specified, the +Y side or +Y refers to the side indicated by the tip of the Y-axis arrow, and the -Y side or -Y refers to the opposite side of the side indicated by the tip of the Y-axis arrow. Unless otherwise specified, the +Z side or +Z refers to the side indicated by the tip of the Z-axis arrow, and the -Z side or -Z refers to the opposite side of the side indicated by the tip of the Z-axis arrow.

[0014] A battery module 1 according to an embodiment will be described with reference to Figures 1 to 4. The battery module 1 according to the embodiment includes a plurality of battery cells 10, a plurality of connection busbars 20, a pair of protectors 30, a plurality of voltage detection terminals 40, a first terminal busbar 51 and a second terminal busbar 52. The virtual plane S shown in Figure 1 is a cross-section passing through approximately the center of the battery module 1 in the Z direction.

[0015] As shown in Figures 1 to 4, multiple battery cells 10 are stacked in the Y direction. As shown in Figures 2 and 3, the battery cell 10 according to this embodiment has a battery element 11, a pair of cover materials 12, a pair of terminals 13, and an outer film 14.

[0016] The battery element 11 has a positive electrode, a negative electrode, and a separator (not shown). For example, multiple positive electrodes and multiple negative electrodes are stacked alternately in the Y direction, with a separator located between adjacent positive and negative electrodes. The structure of the battery element 11 is not limited to this example. In this embodiment, the battery element 11 has a substantially rectangular parallelepiped shape with a pair of faces substantially perpendicular to the X direction, a pair of faces substantially perpendicular to the Y direction, and a pair of faces substantially perpendicular to the Z direction. The lengths of the sides of the battery element 11 are in the order of sides substantially parallel to the Y direction, sides substantially parallel to the Z direction, and sides substantially parallel to the X direction.

[0017] As shown in Figure 3, the pair of cover members 12 are located on both sides of the plurality of battery elements 11 in the X direction. Each cover member 12 covers at least partially the battery element 11. Each cover member 12 is made of an insulator such as resin.

[0018] Unless otherwise specified, the following descriptions of the cover material 12 pertain to the cover material 12 on the -X side. The descriptions of the cover material 12 on the -X side are also applicable to the cover material 12 on the +X side. As can be seen from Figures 2 and 4, the cover material 12 includes a frame 121, a projection frame 122, and a plurality of reinforcing ribs 123.

[0019] - Viewed from the X side, the frame 121 has a roughly rectangular frame shape that surrounds the barrier conductor 131, with a pair of short sides substantially parallel to the Y direction and a pair of long sides substantially parallel to the Z direction. Details of the barrier conductor 131 will be described later. As can be seen from Figure 4, the frame 121 includes a pair of claws 121a that grip the ends of the barrier conductor 131 in the X direction. The barrier conductor 131 is held in place by the frame 121 when its ends are gripped by the pair of claws 121a. The pair of claws 121a are provided around the entire circumference or on a portion thereof of the barrier conductor 131. In the cross-section shown in Figure 4, each of the ends of the barrier conductor 131 in the Y direction is gripped by the pair of claws 121a.

[0020] As can be seen from Figure 4, the projection frame 122 protrudes from the frame body 121 toward the -X side. As shown in Figure 2, when viewed from the -X side, the projection frame 122 has a roughly rectangular frame shape that surrounds the projection conductor 132, with a pair of short sides that are roughly parallel to the Y direction and a pair of long sides that are roughly parallel to the Z direction. Details of the projection conductor 132 will be described later. Other projection frames may protrude from the frame body 121 toward the +X side. At least one of the projection frame 122 on the -X side of the frame body 121 and the other projection frames on the +X side of the frame body 121 may not be provided.

[0021] As shown in Figure 2, the multiple reinforcing ribs 123 are located between the -X plane of the frame 121 and the inner surface of the projection frame 122 around the protruding conductor 132. Viewed from the -X side, the multiple reinforcing ribs 123 are arranged substantially regularly along the inner surface of the projection frame 122 around the protruding conductor 132. The strength of the cover material 12 can be reinforced by the multiple reinforcing ribs 123. The number and arrangement of the reinforcing ribs 123 are not limited to the example shown in Figure 2. The reinforcing ribs 123 may not be provided at all.

[0022] As shown in Figure 3, the pair of terminals 13 are located on both sides of the battery element 11 in the X direction. One terminal 13 and the positive electrode of the battery element 11 are electrically connected to each other via a positive electrode current collector (not shown) that is drawn out from the battery element 11 toward that one terminal 13. The other terminal 13 and the negative electrode of the battery element 11 are electrically connected to each other via a negative electrode current collector (not shown) that is drawn out from the battery element 11 toward that other terminal 13. The terminals 13 are made of a suitable metal depending on the polarity of the electrodes electrically connected to the terminals 13.

[0023] Unless otherwise specified, the following descriptions of terminal 13 pertain to the terminal 13 on the -X side. The descriptions of terminal 13 on the -X side are also applicable to terminal 13 on the +X side. As can be seen from Figures 2 and 4, terminal 13 includes a barrier conductor 131 and a protruding conductor 132.

[0024] As shown in Figure 4, the barrier conductor 131 is located on the -X side relative to the battery element 11. The barrier conductor 131 is made of metal. As will be described later, the pair of cover materials 12 and outer film 14 form a housing space that accommodates the battery element 11 and the electrolyte. The barrier conductor 131 prevents moisture from permeating from the -X side of the barrier conductor 131 into the housing space.

[0025] As shown in Figures 2 and 4, the protruding conductor 132 protrudes from approximately the center of the -X plane of the barrier conductor 131 toward the -X side. The protruding conductor 132 is made of a metal block. In the example shown in Figure 2, when viewed from the -X side, the protruding conductor 132 has a roughly rectangular shape with a pair of short sides substantially parallel to the Y direction and a pair of long sides substantially parallel to the Z direction. The shape of the protruding conductor 132 is not limited to the example shown in Figure 2.

[0026] As shown in Figure 2, a pair of plugs 131a are provided on both sides in the Z direction of the protruding conductor 132 of the barrier conductor 131. The pair of plugs 131a close the through holes on both sides in the Z direction of the protruding conductor 132 of the barrier conductor 131. These through holes in the barrier conductor 131 are used for injecting electrolyte into the containment space and for releasing gas from the containment space.

[0027] The outer film 14 is a laminate film comprising, for example, a metal layer such as an aluminum layer and resin layers formed on both sides of the metal layer. The configuration of the laminate film is not limited to this example. The outer film 14 is wrapped around the battery element 11 and a pair of cover materials 12 around the central axis of the battery element 11 in the X direction. The outer surface of the cover material 12 on the -X side around the central axis of the battery element 11 and the inner surface of the outer film 14 at the -X side end around the central axis of the battery element 11 are joined to each other, for example, by heat welding. The outer surface of the cover material 12 on the +X side around the central axis of the battery element 11 and the inner surface of the outer film 14 at the +X side end around the central axis of the battery element 11 are joined to each other, for example, by heat welding. Between the pair of cover materials 12, parts of the outer film 14 are joined to each other by heat fusion. With the outer film 14 and the pair of lid materials 12, and the parts of the outer film 14 between the pair of lid materials 12, joined to each other, the outer film 14 serves as an outer material that seals the battery element 11. In the state where the outer film 14 seals the battery element 11, the pair of lid materials 12 and the outer film 14 form a housing space that accommodates the battery element 11 and the electrolyte.

[0028] In this embodiment, the inner surface of the -X side end of the outer film 14 is joined to the outer surface of the -X side projection frame 122. Therefore, compared to the case where the -X side projection frame 122 is not provided, the joining area between the inner surface of the -X side end of the outer film 14 and the outer surface of the -X side cover material 12 can be increased, thereby improving the sealing performance between the -X side end of the outer film 14 and the -X side cover material 12. The same applies to the inner surface of the +X side end of the outer film 14 and the outer surface of the +X side projection frame 122.

[0029] The connecting busbar 20 is made of, for example, metal. Multiple battery cells 10 are connected in series sequentially via multiple connecting busbars 20, from the battery cell 10 furthest to the +Y side to the battery cell 10 furthest to the -Y side. In the example shown in Figure 3, the -X side connecting busbar 20 electrically connects the protruding conductor 132 of the odd-numbered battery cells 10 from the +Y side to the protruding conductor 132 of the battery cell 10 located on the -Y side relative to that battery cell 10. The +X side connecting busbar 20 electrically connects the protruding conductor 132 of the even-numbered battery cells 10 from the +Y side to the protruding conductor 132 of the battery cell 10 located on the -Y side relative to that battery cell 10. The electrical connection of multiple battery cells 10 via multiple connecting busbars 20 is not limited to the example shown in Figure 3.

[0030] Unless otherwise specified, the following descriptions of the connection busbar 20 pertain to the -X side connection busbar 20. The descriptions of the -X side connection busbar 20 are also applicable to the +X side connection busbar 20. As shown in Figures 1, 2, and 4, the connection busbar 20 includes a central region 21, a pair of first folded regions 22, and a pair of second folded regions 23.

[0031] The central region 21 is located on the -X side with respect to the region between the protruding conductors 132 of the battery cells 10 that are electrically connected via the connecting busbar 20. The pair of first bent regions 22 are bent on the -X side from both ends of the central region 21 in the Y direction. The pair of second bent regions 23 are bent away from each other in the Y direction from the +X side ends of the pair of first bent regions 22. The pair of second bent regions 23 are located on the -X side with respect to the protruding conductors 132 of the battery cells 10 that are electrically connected via the connecting busbar 20. Each protruding conductor 132 and each second bent region 23 are electrically connected to each other by joining, for example, laser welding.

[0032] In this embodiment, even if a misalignment occurs in the Y direction between the battery cells 10, the bent shape between the central region 21 and the pair of first bent regions 22, and the bent shape between the pair of first bent regions 22 and the pair of second bent regions 23 can be flexed. By flexing these bent shapes, the connecting busbar 20 can follow the misalignment in the Y direction between the battery cells 10.

[0033] As shown in Figure 1, the pair of protectors 30 are located on both sides of the multiple battery cells 10 in the X direction. Each protector 30 is made of an insulator such as resin.

[0034] Unless otherwise specified, the following descriptions of the protector 30 pertain to the protector 30 on the -X side. The descriptions of the protector 30 on the -X side are also applicable to the protector 30 on the +X side.

[0035] The protector 30 is positioned substantially perpendicular to the X direction. As shown in Figure 1, when viewed from the -X side, the protector 30 has a substantially rectangular shape with a pair of long sides substantially parallel to the Y direction and a pair of short sides substantially parallel to the Z direction. Multiple frames 31 are provided on the -X side of the protector 30. The area enclosed by the frames 31 of the protector 30 defines an opening in which the connecting busbar 20 is placed. The protector 30 covers the -X side portions of the multiple battery cells 10, except for the areas enclosed by each frame 31.

[0036] As shown in Figures 1, 3, and 4, the protector 30 has a plurality of beams 32. The protector 30 and the plurality of beams 32 are, for example, integrally molded. As shown in Figures 1 and 4, each beam 32 is located on the +X side of the central region 21 of each connecting busbar 20. The beams 32 extend in the Z direction. As can be seen from Figures 1 and 4, two pillars 33 are provided on the -X side of each beam 32. As shown in Figure 1, the two pillars 33 are aligned in the Z direction and penetrate the +Z side portion and the -Z side portion of the central region 21 in the X direction. By heat-crimping the -X side tip of the pillars 33 while they are penetrating the central region 21, each connecting busbar 20 and the protector 30 can be fixed to each other.

[0037] As can be seen from Figures 3 and 4, the protector 30 has a plurality of first partition members 34. The protector 30 and the plurality of first partition members 34 are, for example, integrally molded. Therefore, by positioning the protector 30 in an appropriate position relative to the plurality of battery cells 10, the plurality of first partition members 34 can also be positioned in an appropriate position relative to the plurality of battery cells 10. Each first partition member 34 is provided on the +X side of each beam 32. Thus, each first partition member 34 is at least partially located between the connecting bus bar 20 and the battery cells 10 that are electrically connected via the connecting bus bar 20. As shown in Figure 3, viewed from the +Z side, each first partition member 34 is located between the terminals 13 that are electrically connected via the connecting bus bar 20. The first partition member 34 extends in the Z direction. As shown in Figure 4, the first partition member 34 includes a first covering 341 and a pair of first extending bodies 342. Details of the first partition member 34 will be described later.

[0038] As can be seen from Figures 3 and 4, the protector 30 has a plurality of second partition members 35. The protector 30 and the plurality of second partition members 35 are, for example, integrally molded. Therefore, by positioning the protector 30 in an appropriate position relative to the plurality of battery cells 10, the plurality of second partition members 35 can also be positioned in an appropriate position relative to the plurality of battery cells 10. Each second partition member 35 is located between adjacent connecting busbars 20 in the Y direction. The second partition member 35 extends in the Z direction. As shown in Figure 4, the second partition member 35 includes a second covering 351 and a pair of second extensions 352. Details of the second partition member 35 will be described later.

[0039] Multiple voltage detection terminals 40 are mounted on the -X side of multiple connection busbars 20. Each connection busbar 20 and each voltage detection terminal 40 are electrically connected to each other by joining, for example, laser welding. For example, multiple voltage detection terminals 40 are attached to wiring such as harnesses and flexible printed circuits (FPCs) attached to the protector 30. In this example, the protector 30 and the multiple voltage detection terminals 40 are connected to each other via wiring such as harnesses and FPCs.

[0040] As shown in Figure 1, the first terminal busbar 51 is located at the -Y end of the -X side protector 30. The first terminal busbar 51 is electrically connected to the -X side terminal 13 of the battery cell 10 located furthest to the -Y side. The second terminal busbar 52 is located at the +Y side end of the +X side protector 30. The second terminal busbar 52 is electrically connected to the +X side terminal 13 of the battery cell 10 located furthest to the +Y side.

[0041] The battery module 1 according to this embodiment will be described further with reference to Figure 4.

[0042] For explanation purposes, the -X side end of the exterior film 14 and the -X side end of the frame body 121 are distinguished as a first end 10a and a second end 10b. The first end 10a of the exterior film 14 and the frame body 121 is an end located between the -X side terminals 13 of the battery cells 10 electrically connected via the -X side connection bus bar 20. The second end 10b of the exterior film 14 and the frame body 121 is an end located between the -X side terminals 13 of the battery cells 10 electrically connected via the +X side connection bus bar 20.

[0043] In the embodiment, the exterior film 14 contains a conductor such as a metal film. The conductor contained in the exterior film 14 is exposed from the first end 10a and the second end 10b of the exterior film 14.

[0044] The first covering body 341 covers the first end 10a of the exterior film 14 and the frame body 121. The +X surface of the first covering body 341 and the first end 10a may be in contact with each other, or may be spaced apart from each other in the X direction. By the first covering body 341 covering the first end 10a, the first partition member 34 partitions the conductor at the first end 10a of the exterior film 14 and the connection bus bar 20 located on the -X side with respect to the first end 10a. Therefore, electrical insulation between the conductor at the first end 10a of the exterior film 14 and the connection bus bar 20 located on the -X side with respect to the first end 10a can be ensured.

[0045] As shown in FIG. 4, the pair of first extending bodies 342 extend toward the +X side from both side portions in the Y direction of the first covering body 341. Therefore, compared with the case where the pair of first extending bodies 342 are not provided, the creepage distance between the conductor at the first end portion 10a of the exterior film 14 and the connection bus bar 20 located on the -X side with respect to the first end portion 10a can be increased by an amount corresponding to the pair of first extending bodies 342. Accordingly, compared with the case where the pair of first extending bodies 342 are not provided, electrical insulation between the conductor at the first end portion 10a of the exterior film 14 and the connection bus bar 20 located on the -X side with respect to the first end portion 10a can be ensured. The shape of the pair of first extending bodies 342 is not limited to the shape shown in FIG. 4 as long as the creepage distance can be increased. At least one of the pair of first extending bodies 342 may not be provided.

[0046] In the example shown in FIG. 4, the pair of first extending bodies 342 extend toward a side away from at least a part of the connection bus bar 20 located on the -X side relative to the pair of first extending bodies 342. Specifically, the pair of first extending bodies 342 extend toward the +X side away from the central region 21 of the connection bus bar 20. Therefore, compared with the case where the pair of first extending bodies 342 extend toward the -X side approaching the central region 21, electrical insulation between the distal ends of the pair of first extending bodies 342 and the connection bus bar 20 located on the -X side relative to the pair of first extending bodies 342 can be ensured.

[0047] Furthermore, in the example shown in FIG. 4, when viewed from the +Z side, the pair of first extending bodies 342 extend such that the distance in the Y direction between the pair of first extending bodies 342 increases as going toward the +X side. That is, when viewed from the +Z side, each first extending body 342 extends obliquely with respect to the X direction. The shape of each first extending body 342 is not limited to the example shown in FIG. 4.

[0048] In the example shown in FIG. 4, each first extending body 342 partitions the protruding conductor 132 and the first end portion 10a of the exterior film 14. Therefore, electrical insulation between the protruding conductor 132 and the conductor at the first end portion 10a of the exterior film 14 can be ensured by the first extending body 342.

[0049] In this embodiment, the beam 32 constitutes the first partition member 34. Therefore, it can also be said that the first partition member 34 has the beam 32. For example, the beam 32 and the first partition member 34 are molded together. As shown in Figure 4, when viewed from the +Z side, the beam 32 protrudes from the first covering 341 to the -X side. In the example shown in Figure 4, when viewed from the +Z side, the -X side end of the beam 32 is located to the -X side than the -X side end of the protruding conductor 132. Therefore, it is easier to ensure electrical insulation between adjacent protruding conductors 132 in the Y direction using the beam 32. The -X side end of the beam 32 and the -X side end of the protruding conductor 132 may be aligned in the X direction. Alternatively, the -X side end of the beam 32 may be located to the +X side than the -X side end of the protruding conductor 132.

[0050] In the example shown in Figure 4, when viewed from the +Z side, the central region 21 of the connecting busbar 20 is located on the -X side of the -X end of the beam 32, and when viewed from the +Z side, the second bent region 23 of the connecting busbar 20 is located on the -X side of the -X end of the protruding conductor 132. Furthermore, when viewed from the +Z side, the first bent region 22 of the connecting busbar 20 extends from the central region 21 to the second bent region 23, towards the side where the multiple battery cells 10 are located. Therefore, even if the -X end of the beam 32 is located on the -X side of the protruding conductor 132, the connecting busbar 20 can be easily positioned. The shape of the connecting busbar 20 may vary depending on the positional relationship between the -X end of the protruding conductor 132 and the -X end of the beam 32.

[0051] The second covering 351 covers the outer film 14 and the second end 10b of the frame 121. The +X surface of the second covering 351 and the second end 10b may be in contact with each other or may be separated from each other in the X direction. By covering the second end 10b with the second covering 351, the second partition member 35 separates the conductor at the second end 10b of the outer film 14 from the connecting busbars 20 that are electrically connected to the terminals 13 located on both sides in the Y direction relative to the second end 10b. Thus, electrical insulation can be ensured between the conductor at the first end 10a of the outer film 14 and the connecting busbars 20 that are electrically connected to the terminals 13 located on both sides in the Y direction relative to the second end 10b.

[0052] As shown in Figure 4, the pair of second extensions 352 extend from both sides of the second covering 351 in the Y direction toward the -X direction. Therefore, compared to the case where the pair of second extensions 352 are not provided, the creepage distance between the conductor at the second end 10b of the outer film 14 and the connecting busbars 20 electrically connected to the terminals 13 located on both sides of the second end 10b in the Y direction can be increased by the amount of the pair of second extensions 352. Thus, compared to the case where the pair of second extensions 352 are not provided, electrical insulation can be ensured between the conductor at the second end 10b of the outer film 14 and the connecting busbars 20 electrically connected to the terminals 13 located on both sides of the second end 10b in the Y direction. The shape of the pair of second extensions 352 is not limited to the shape shown in Figure 4, as long as the creepage distance can be increased. At least one of the pair of second extensions 352 may not be provided.

[0053] In the example shown in Figure 4, the pair of second extensions 352 extend away from at least a portion of the connecting busbars 20 located on both sides of the pair of second extensions 352 in the Y direction. Specifically, the pair of second extensions 352 extend away from the second bending regions 23 located on both sides of the pair of second extensions 352 in the Y direction, on the -X side. Therefore, compared to the case where the pair of first extensions 342 extend towards the second bending regions 23 on the +Y or -Y side, it is possible to ensure electrical insulation between the tips of the pair of second extensions 352 and the connecting busbars 20 located on both sides of the pair of second extensions 352 in the Y direction.

[0054] In this embodiment, each second extending body 352 is a part of the frame 31. Specifically, when viewed from the -X side, each second extending body 352 is a portion of the frame 31 that extends in the Z direction. The second extending body 352 may be provided separately from the frame 31.

[0055] In the example shown in Figure 4, the -X side end of each second extension 352 is located on the -X side of the central region 21 of the connecting busbar 20. As shown in Figure 4, the first covering 341 and beam 32 of the first partition member 34 and the central region 21 of the connecting busbar 20 overlap in the X direction. In the example shown in Figure 4, the combined X-direction dimension of the second covering 351 and second extension 352 of the second partition member 35 is larger than the combined X-direction dimension of the first covering 341 and beam 32 of the first partition member 34 and the central region 21 of the connecting busbar 20. Therefore, the second partition member 35 makes it easier to ensure electrical insulation between adjacent connecting busbars 20 in the Y direction.

[0056] The embodiments of the present invention have been described above with reference to the drawings, but these are merely examples of the present invention, and various other configurations can also be adopted.

[0057] In this embodiment, the outer casing of the battery cell 10 is an outer film 14 wrapped around the battery element 11 and a pair of lid materials 12. The outer casing of the battery cell 10 is not limited to the outer film 14 according to this embodiment. For example, the battery cell 10 may not have lid materials 12 and may have a pouch-shaped outer casing that encloses the battery element 11.

[0058] This application claims priority based on Japanese Patent Application No. 2025-047148, filed on 21 March 2025, and incorporates all of its disclosures herein.

[0059] 1 Battery module, 10 Battery cell, 10a First end, 10b Second end, 11 Battery element, 12 Cover material, 121 Frame, 121a Claw, 122 Projection frame, 123 Reinforcement rib, 13 Terminal, 131 Barrier conductor, 131a Plug, 132 Protruding conductor, 14 Outer film, 20 Connecting bus bar, 21 Central region, 22 First folding region, 23 Second folding region, 30 Protector, 31 Frame, 32 Beam, 33 Pillar, 34 First partition member, 341 First covering, 342 First extension, 35 Second partition member, 351 Second covering, 352 Second extension, 40 Voltage detection terminal, 51 First terminal bus bar, 52 Second terminal bus bar

Claims

1. A battery module comprising: a plurality of battery cells, each having a battery element, a cover material that at least partially covers the battery element, and an outer material including a conductor that is wrapped around the battery element and the cover material; busbars that electrically connect the battery cells to each other; and partition members that separate the conductor and the busbars.

2. The battery module according to claim 1, wherein the partition member has a first portion that covers the conductor and a second portion that extends from the first portion.

3. The battery module according to claim 1, wherein each of the plurality of battery cells further has terminals electrically connected to the battery element, and the partition member is at least partially located between the terminals electrically connected via the busbar.

4. The battery module according to claim 3, wherein the plurality of battery cells are stacked in a first direction, the terminals have ends located on one side in a second direction perpendicular to the first direction, and the partition member has ends located on the side of the terminals that is on the side of the terminals.

5. The battery module according to claim 4, wherein the busbar has a first region located on one side of the end of the partition member, a second region located on one side of the end of the terminal, and a third region extending from the first region to the second region toward the side toward where the plurality of battery cells are located.

6. The battery module according to claim 3, wherein the exterior material has an end located between the terminals that are electrically connected via the busbar, and at least a portion of the partition member separates the terminals from the end of the exterior material.

7. The battery module according to claim 1, wherein the partition member is at least partially located between adjacent busbars.

8. The battery module according to claim 7, wherein the plurality of battery cells are stacked in a first direction, the busbar has an end located on one side in a second direction perpendicular to the first direction, and the partition member has an end located on the side of the busbar that is further to the side.

9. The battery module according to claim 1, wherein the plurality of battery cells are stacked in a first direction, each of the plurality of battery cells further has terminals electrically connected to the battery element, and the partition member includes a first partition member at least partially located between the terminals electrically connected via the busbars, and a second partition member at least partially located between adjacent busbars, at least a portion of the first partition member and at least a portion of the busbars overlap in a second direction perpendicular to the first direction, and the dimension of the second partition member in the second direction is greater than the sum of the dimension of the at least portion of the first partition member and the at least portion of the busbars in the second direction.

10. The battery module according to any one of claims 1 to 9, further comprising a protector that at least partially covers the plurality of battery cells, wherein the protector has the partition member.

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