Battery module

Abstract

The problem addressed by the present invention is that of making it possible to efficiently cool battery cells. In order to solve the problem, this battery module is provided with a plurality of battery cells, one or more bus bars, and a cooling member. The bus bar electrically connects the electrodes of the plurality of battery cells to each other. The cooling member is brought into contact with the inner side of a portion of the bus bar, which is brought into contact with the electrode, in a heat-transfer manner. According to the present structure, heat transferred from the electrode of the battery cell to the bus bar can be dissipated to the cooling member on the inner side of the electrode. Accordingly, it is possible to efficiently cool the battery cells.

Description

Technical Field

[0001] The present invention relates to a battery module comprising a plurality of battery cells. Background Art

[0002] In recent years, electric vehicles such as pure electric vehicles (EV) and hybrid electric vehicles (HEV) are becoming more popular from the perspective of reducing carbon dioxide emissions and reducing adverse effects on the earth's environment. In a battery module mounted on an electric vehicle, there is a battery module having a plurality of battery cells and a busbar that electrically connects the electrodes of these battery cells to each other.

[0003] [Prior Technical Literature]

[0004] (Patent Document)

[0005] Patent Document 1: Japanese Patent Application Publication No. 2006-271063 Summary of the invention

[0006] [Problems to be solved by the invention]

[0007] An object of the present invention is to efficiently cool the battery cells in such a battery module.

[0008] [Technical means to solve the problem]

[0009] The inventors have found that by bringing a cooling member into contact with the back side of a portion of a bus bar that contacts an electrode, the battery cells can be efficiently cooled, and have completed the present invention. The present invention is a battery module according to the following (1) to (10).

[0010] (1) A battery module comprising:

[0011] Multiple battery cells;

[0012] One or more bus bars electrically connecting the electrodes of the plurality of battery cells; and

[0013] The cooling member is in heat-transferable contact with the back side of a portion of the bus bar that contacts the electrode.

[0014] According to this structure, the heat transferred from the electrode of the battery cell to the bus bar can be dissipated to the cooling member located on the back side of the electrode. Therefore, the battery cell can be cooled efficiently.

[0015] (2) The battery module according to (1) above, wherein an inserted portion is provided on the back side of a portion of the bus bar that contacts the electrode.

[0016] The cooling member has a protrusion that is inserted into the inserted portion and abuts against a bottom portion of the inserted portion.

[0017] According to this structure, by inserting the protrusion of the cooling member into the recess of the busbar, the cooling member can be positioned relative to the busbar. Moreover, the protrusion of the cooling member abuts against the bottom of the inserted portion. Therefore, the protrusion of the cooling member abuts against the inner side of the portion of the busbar that abuts against the electrode. Therefore, the heat transferred from the electrode to the busbar can be dissipated to the protrusion of the cooling member located on the inner side of the electrode.

[0018] (3) The battery module according to (1) or (2) above, wherein the cooling member is made of rubber.

[0019] According to this structure, the height deviation of the generatrix can be absorbed within the elastic region of the rubber.

[0020] (4) The battery module according to (3), comprising:

[0021] A housing for accommodating the battery cells, the busbars and the cooling components; and

[0022] a cover body, covering the opening of the shell; and

[0023] The surface of the cooling member opposite to the busbar side is in contact with the cover.

[0024] According to this structure, the heat dissipated from the electrode to the cooling member via the bus bar can be further dissipated to the cover 30. Therefore, the battery cell can be cooled more efficiently.

[0025] (5) The battery module according to (3) above, wherein the cooling member is made of rubber having heat conductivity and insulation properties.

[0026] According to this configuration, the cooling member can ensure heat conductivity between the bus bar and the cover body and insulation between the bus bar and the cover body.

[0027] (6) The battery module according to (5) above, wherein the rubber is ethylene propylene diene (EPDM) rubber.

[0028] EPDM rubber has heat conductivity and insulation properties. Therefore, the EPDM rubber can ensure the heat conductivity between the busbar and the cover body and the insulation between the busbar and the cover body.

[0029] (7) The battery module according to (5) above, comprising a plurality of the bus bars.

[0030] A portion of the cooling member is present between adjacent bus bars.

[0031] According to this configuration, the insulation between adjacent bus bars can be ensured by utilizing the cooling member.

[0032] (8) The battery module according to (4), wherein a water jacket is installed on the outer side of the cover.

[0033] A refrigerant flows between the water jacket and the cover.

[0034] According to this structure, the heat of the battery cell that is dissipated from the electrode to the cover via the bus bar and the cooling member can be further dissipated to the coolant. Therefore, the battery cell can be cooled more efficiently.

[0035] (9) The battery module according to (1) or (2), wherein the bus bar and the cooling member have concave-convex shapes that fit together.

[0036] According to this structure, the positional deviation of the cooling component relative to the busbar can be prevented. Thus, the cooling component can be kept at the optimal position relative to the busbar to maximize the heat dissipation performance. Therefore, in this aspect, the battery cell can also be efficiently cooled.

[0037] (10) A battery module comprising:

[0038] Multiple battery cells;

[0039] One or more bus bars electrically connecting the electrodes of the plurality of battery cells; and

[0040] A cooling member is heat-conductably abutted against the busbar; and

[0041] The bus bar and the cooling member have concave-convex shapes that fit with each other.

[0042] According to this configuration, the battery cells can also be efficiently cooled, similarly to the above-mentioned case (9).

[0043] (Effects of the Invention)

[0044] As described above, according to the inventions of (1) and (10), the battery cells can be efficiently cooled. Furthermore, according to the configurations of (2) to (9) citing (1), respective additional effects can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a side cross-sectional view of a battery module according to the first embodiment. Figure 2 Figure 2 is a cross-section of line II.

[0046] Figure 2 It is shown Figure 1 FIG. 5 is a cross-section diagram of line II-II.

[0047] Figure 3 It is shown Figure 1 FIG. 5 is a cross-section diagram of line III-III.

[0048] Figure 4 Yes Figure 1 A magnified portion of the image.

[0049] Figure 5 It is a three-dimensional diagram showing the busbar and cooling components.

[0050] Figure 6 It is an exploded perspective view showing the busbar and cooling components.

[0051] Figure 7 FIG. 1 is a side cross-sectional view of a battery module according to a second embodiment. DETAILED DESCRIPTION

[0052] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments and can be implemented with appropriate changes within the scope of the present invention.

[0053] [First embodiment]

[0054] like Figure 1 As shown, the battery module 100 includes a housing 80 , a plurality of battery cells 70 , a plurality of bus bars 50 , a plurality of cooling members 40 , and a cover 30 .

[0055] The following, such as Figure 2 As shown in the figure, two predetermined directions orthogonal to each other in the horizontal plane are referred to as "X direction" and "Y direction". In addition, one of the X directions is referred to as "X-direction", and the opposite direction thereof is referred to as "X+ direction". In addition, one of the Y directions is referred to as "Y-direction", and the opposite direction thereof is referred to as "Y+ direction".

[0056] like Figure 1 As shown, the housing 80 is in a box shape with an opening toward the upper side. The housing 80 is made of metal or the like. The housing 80 accommodates the battery cells 70 , the bus bars 50 , and the cooling members 40 . The cover 30 covers the opening of the housing 80 .

[0057] like Figure 3As shown, each battery cell 70 has an outer package that is elongated in the X direction. Hereinafter, a component formed by stacking a plurality of battery cells 70 in the Y direction is referred to as a "battery stack Bs". The housing 80 accommodates two battery stacks Bs in parallel in the X direction. In each battery stack Bs, a diaphragm 79 is provided between each two battery cells 70 arranged in the Y direction. The diaphragm 79 is made of resin or the like.

[0058] like Figure 3 As shown, each battery cell 70 has a positive electrode p at one end in the X direction of the upper surface of the outer package, and a negative electrode n at the other end in the X direction of the upper surface of the outer package 72. Specifically, for a predetermined plurality of battery cells 70, a positive electrode p is arranged on the X- direction side, and a negative electrode n is arranged on the X+ direction side. On the other hand, for the other battery cells 70, a negative electrode n is arranged on the X- direction side, and a positive electrode p is arranged on the X+ direction side.

[0059] like Figure 2 As shown, most of the busbars 50 electrically connect the electrodes p and n of the battery cells 70 adjacent in the X direction or the Y direction. On the other hand, a predetermined busbar 50 electrically connects the positive electrode p of the battery cell 70 on the most positive side electrically to the positive electrode P of the entire battery module 100. In addition, another busbar 50 electrically connects the negative electrode n of the battery cell 70 on the most negative side electrically to the negative electrode N of the entire battery module 100. Based on the above, in this embodiment, all the battery cells 70 in the battery module 100 are connected in series.

[0060] like Figure 6 As shown in FIG. 1 , each bus bar 50 is formed by, for example, bending a metal plate. An inserted portion 55 is provided just above a portion of each bus bar 50 that contacts the electrodes p and n.

[0061] Specifically, if Figure 4 As shown in FIG. 1 , each bus bar 50 includes a bus bar base 52 and a folded portion 54. The bus bar base 52 is a plate extending in the X direction and the Y direction. The folded portion 54 is provided for each electrode p, n. Each folded portion 54 is, for example, Figure 4 As shown, it is a shape that extends downward from the end of the Y direction in the busbar base 52 and then extends inward in the Y direction, or a shape that extends downward from the end of the X direction and then extends inward in the X direction. These folded parts 54 are welded to the electrodes p, n. A through hole 53 is formed in the portion of the busbar base 52 located directly above the electrodes p, n. The portion from the through hole 53 to the folded part 54 constitutes the inserted portion 55. Therefore, the inner surface of the portion of the folded part 54 that abuts against the electrodes p, n constitutes the bottom surface of the inserted portion 55.

[0062] like Figure 1 As shown, a cooling member 40 is provided for each bus bar 50. Each cooling member 40 is in thermal contact with the upper surface of the bus bar 50 corresponding to the cooling member 40. Each cooling member 40 is made of rubber having thermal conductivity and insulation properties, more specifically EPDM rubber (ethylene propylene diene rubber).

[0063] like Figure 6 As shown in FIG. 4 , each cooling member 40 includes a cooling member base 42, an insulating portion 47, and a protrusion 45. Figure 5 As shown in FIG. 1 , the cooling member base 42 is in the shape of a plate extending in the X direction and the Y direction. The insulating portion 47 protrudes downward from both ends of the cooling member base 42 in the Y direction. Figure 4 As shown in FIG. 1 , the protrusion 45 is provided for each electrode p, n. Each protrusion 45 protrudes downward from the cooling member base 42. Each protrusion 45 is inserted into the corresponding insertion portion 55 and abuts against the bottom of the insertion portion 55.

[0064] like Figure 5 As shown, the insulating portion 47 on the Y+ side of each cooling member 40 abuts against the end of the busbar 50 on the Y+ direction side from the Y+ direction side. The insulating portion 47 on the Y- side of each cooling member 40 abuts against the end of the busbar 50 on the Y- direction side from the Y- direction side. Therefore, between the adjacent busbars 50 in the Y direction, there is an insulating portion 47 as a part of the cooling member 40. Figure 4 As shown, the upper surface of the cooling member base 42 abuts against the lower surface of the cover 30 .

[0065] According to the above structure, Figure 4 As shown, the heat of each battery cell 70 is dissipated from the electrodes p, n to the cover 30 via the bus bar 50 and the cooling member 40 .

[0066] Hereinafter, the structure and effects of this embodiment will be summarized.

[0067] like Figure 4 As shown, the cooling member 40 is in heat transfer contact with the inner side of the portion of the bus bar 50 that contacts the electrodes p and n. Therefore, the heat transferred from the electrodes p and n of the battery cell 70 to the bus bar 50 can be dissipated to the cooling member 40 located in the inner side of the electrodes p and n. Therefore, the battery cell 70 can be efficiently cooled.

[0068] An inserted portion 55 is provided on the inner side of the portion of the bus bar 50 that contacts the electrodes p and n. The protrusion 45 of the cooling member 40 is inserted into the inserted portion 55. Therefore, the cooling member 40 can be positioned relative to the bus bar 50. Moreover, the protrusion 45 of the cooling member 40 contacts the bottom of the inserted portion 55, that is, on the inner side of the portion of the bus bar 50 that contacts the electrodes p and n. Therefore, the heat transferred from the electrodes p and n to the bus bar 50 can be dissipated to the protrusion 45 of the cooling member 40 on the inner side of the electrodes p and n.

[0069] The cooling member 40 is made of rubber, so that the height deviation of the busbar 50 can be absorbed within the elastic region of the rubber.

[0070] The upper surface of the cooling member 40, that is, the surface of the cooling member 40 opposite to the bus bar 50 side, contacts the cover 30. Therefore, the heat dissipated from the electrodes p,n to the cooling member 40 via the bus bar 50 can be further dissipated to the cover 30. Therefore, the battery cell 70 can be cooled more efficiently.

[0071] The cooling member 40 is a rubber having heat conductivity and insulation properties. Therefore, the cooling member 40 can ensure heat conductivity between the bus bar 50 and the cover 30 and insulation between the bus bar 50 and the cover 30 .

[0072] More specifically, the cooling member 40 is EPDM rubber. The EPDM rubber has heat conductivity and insulation properties. Therefore, the heat conductivity and insulation properties between the busbar 50 and the cover 30 can be ensured by the EPDM rubber.

[0073] An insulating portion 47 that is a part of the cooling member 40 exists between the adjacent bus bars 50. Therefore, the cooling member 40 can ensure insulation between the adjacent bus bars 50.

[0074] like Figure 6 As shown in FIG. 1 , the busbar 50 is provided with an inserted portion 55. The cooling member 40 has a protrusion 45 inserted into the inserted portion 55. That is, the busbar 50 and the cooling member 40 have concave-convex shapes that fit each other. Thus, the positional displacement of the cooling member 40 relative to the busbar 50 can be prevented. Figure 4 As shown, the cooling member 40 can be kept at an optimal position relative to the bus bar 50 to maximize the heat dissipation performance. Therefore, in this aspect, the battery cell 70 can also be efficiently cooled.

[0075] [Second embodiment]

[0076] Next, refer to Figure 7The second embodiment will be described. This embodiment is based on the first embodiment, and the description will be mainly focused on the points that are different from the first embodiment, and the description of the points that are the same as or similar to the first embodiment will be appropriately omitted.

[0077] like Figure 7 As shown, a water jacket 20 is installed above the cover 30, that is, outside the cover 30. The space between the water jacket 20 and the cover 30 constitutes a flow path Fp. Refrigerant Rf flows in the flow path Fp.

[0078] According to the present embodiment, the coolant Rf flows between the water jacket 20 and the cover 30. Therefore, the heat of the battery cell 70 which is dissipated from the electrodes p,n to the cover 30 via the busbar 50 and the cooling member 40 can be further dissipated to the coolant Rf. Therefore, the battery cell 70 can be cooled more efficiently.

[0079] [Other embodiments]

[0080] The above-described embodiment can be modified as follows, for example. Figure 4 The cooling member 40 shown may be made of rubber other than EPDM rubber, and more specifically, may be made of silicone rubber having good heat conductivity. Figure 3 The housing 80 shown may contain only one battery stack Bs or three or more. Figure 2 In the housing 80 shown, a plurality of parallel connection bodies of two or three or other predetermined numbers of battery cells 70 may be connected in series. Some of the plurality of cooling members 40 may be formed as one body. That is, one cooling member 40 may be provided to span across a plurality of bus bars 50.

[0081] Reference numerals

[0082] 20 Water Jacket

[0083] 30 Cover

[0084] 40 Cooling components

[0085] 45 Protrusions (concave and convex shapes)

[0086] 47 Insulation (part of cooling component)

[0087] 50 Busbar

[0088] 55 Inserted portion (concave and convex shape)

[0089] 70 battery cells

[0090] 80 Shell

[0091] 100 Battery Module

[0092] Fp Flow path (between water jacket and cover)

[0093] Rf Refrigerant

Claims

1. A battery module comprising: Multiple battery cells; One or more bus bars electrically connecting the electrodes of the plurality of battery cells; and The cooling member is in heat-transferable contact with the back side of a portion of the bus bar that contacts the electrode.

2. The battery module according to claim 1, wherein: An inserted portion is provided on the inner side of a portion of the bus bar that contacts the electrode. The cooling member has a protrusion that is inserted into the inserted portion and abuts against a bottom portion of the inserted portion.

3. The battery module according to claim 1 or 2, wherein: The cooling member is made of rubber.

4. The battery module according to claim 3, comprising: A housing for accommodating the battery cells, the busbars and the cooling components; and a cover body, covering the opening of the shell; and The surface of the cooling member opposite to the busbar side is in contact with the cover.

5. The battery module according to claim 3, wherein: The cooling member is made of rubber having heat conductivity and insulation properties.

6. The battery module according to claim 5, wherein: The aforementioned rubber is ethylene propylene diene rubber.

7. The battery module according to claim 5, comprising a plurality of the bus bars. A portion of the cooling member is present between adjacent bus bars.

8. The battery module according to claim 4, wherein: A water jacket is installed on the outer side of the cover. A refrigerant flows between the water jacket and the cover.

9. The battery module according to claim 1 or 2, wherein: The bus bar and the cooling member have concave-convex shapes that fit with each other.

10. A battery module comprising: Multiple battery cells; One or more bus bars electrically connecting the electrodes of the plurality of battery cells; and A cooling member is heat-conductably abutted against the busbar; and The bus bar and the cooling member have concave-convex shapes that fit with each other.

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