Battery module

Abstract

To allow battery cells to be efficiently cooled.SOLUTION: A battery module includes a plurality of battery cells, at least one bus bar, and a cooling member. The bus bar electrically connects electrodes of the plurality of battery cells to each other. The cooling member contacts, in a heat transferable manner, the back side of portions of the bus bar that contact the electrodes. According to this configuration, the heat transferred from the electrodes of the battery cells to the bus bar can be dissipated to the cooling member on the back side of the electrodes. Therefore, the battery cells can be efficiently cooled.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] In recent years, electric vehicles such as EVs and HEVs have become more widespread from the viewpoint of reducing carbon dioxide emissions and mitigating adverse effects on the global environment. Some battery modules mounted on electric vehicles and the like include a plurality of battery cells and bus bars that electrically connect the electrodes of the battery cells. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-271063 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to enable efficient cooling of battery cells in such a battery module. [Means for solving the problem]

[0005] The present inventors discovered that the battery cells can be efficiently cooled by contacting a cooling member to the rear side of the bus bar at the portion where the bus bar contacts the electrode, and arrived at the present invention. The present invention relates to the following battery modules (1) to (10).

[0006] (1) a plurality of battery cells; One or more bus bars electrically connecting electrodes of the plurality of battery cells to each other; a cooling member in contact with a rear side of the bus bar at a portion where the bus bar is in contact with the electrode, so as to be capable of conducting heat therethrough; A battery module comprising:

[0007] According to this configuration, heat transferred from the electrodes of the battery cells to the bus bars can be dissipated to the cooling member on the rear side of the electrodes, thereby enabling the battery cells to be cooled efficiently.

[0008] (2) An insertion portion is provided on a rear 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 of the inserted portion. The battery module described in (1) above.

[0009] According to this configuration, the cooling member can be positioned relative to the busbar by inserting the protrusion of the cooling member into the recess of the busbar. Moreover, the protrusion of the cooling member abuts the bottom of the inserted portion. As a result, the protrusion of the cooling member abuts the back side of the portion of the busbar that abuts against the electrode. As a result, heat transferred from the electrode to the busbar can be dissipated to the protrusion of the cooling member located on the back side of the electrode.

[0010] (3) The battery module according to (1) or (2), wherein the cooling member is made of rubber.

[0011] According to this configuration, the variation in height of the bus bar can be absorbed within the elastic range of the rubber.

[0012] (4) a case that houses the battery cells, the bus bars, and the cooling member; a cover for covering the opening of the case, a surface of the cooling member opposite to the bus bar side abuts against a cover; The battery module described in (3) above.

[0013] According to this configuration, heat that has been dissipated from the electrodes to the cooling member via the bus bars can be further dissipated to the cover 30. This makes it possible to cool the battery cells more efficiently.

[0014] (5) The battery module according to (3), wherein the cooling member is made of rubber having thermal conductivity and insulating properties.

[0015] According to this configuration, the cooling member can ensure heat transfer between the bus bar and the cover while also ensuring insulation between the bus bar and the cover.

[0016] (6) The battery module according to (5) above, wherein the rubber is EPDM rubber.

[0017] EPDM rubber has heat conductivity and insulation properties, so that the EPDM rubber can ensure heat conductivity between the bus bar and the cover while also ensuring insulation between the bus bar and the cover.

[0018] (7) A plurality of the bus bars are provided, A part of the cooling member is present between adjacent bus bars. The battery module according to (5) above.

[0019] According to this configuration, the cooling member can be used to ensure insulation between adjacent bus bars.

[0020] (8) A water jacket is attached to the outside of the cover, A refrigerant flows between the water jacket and the cover. The battery module according to (4) above.

[0021] With this configuration, the heat of the battery cells that is dissipated from the electrodes via the bus bars and the cooling member to the cover can be further dissipated to the coolant, thereby making it possible to cool the battery cells more efficiently.

[0022] (9) The bus bar and the cooling member have projections and recesses that fit together. The battery module according to (1) or (2).

[0023] This configuration makes it possible to prevent the cooling member from shifting from the bus bar, thereby enabling the cooling member to be held in an optimal position relative to the bus bar and maximizing heat dissipation performance, thereby also allowing the battery cells to be cooled efficiently.

[0024] (10) A plurality of battery cells; One or more bus bars electrically connecting electrodes of the plurality of battery cells to each other; a cooling member in contact with the bus bar so as to be capable of conducting heat therethrough; The bus bar and the cooling member have projections and recesses that fit together. Battery module.

[0025] With this configuration, like the above-mentioned (9), the battery cells can be cooled efficiently. Effect of the Invention

[0026] As described above, the inventions (1) and (10) make it possible to efficiently cool the battery cells. Furthermore, the configurations (2) to (9) that refer to the invention (1) provide additional effects. [Brief description of the drawings]

[0027] [Figure 1] FIG. 3 is a side cross-sectional view showing the battery module of the first embodiment, and more specifically, a cross-section taken along line II in FIG. 2. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Diagram 3] FIG. 2 is a cross-sectional view taken along the line III-III in FIG. [Figure 4] FIG. 2 is an enlarged view of a portion of FIG. [Diagram 5] FIG. 2 is a perspective view showing a bus bar and a cooling member. [Figure 6] FIG. 2 is an exploded perspective view showing a bus bar and a cooling member. [Figure 7] FIG. 6 is a side cross-sectional view showing a battery module according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiment, and can be appropriately modified and implemented without departing from the spirit of the present invention.

[0029] [First embodiment] As shown in FIG. 1, the battery module 100 includes a case 80, a plurality of battery cells 70, a plurality of bus bars 50, a plurality of cooling members 40, and a cover 30.

[0030] Hereinafter, as shown in Figure 2, two predetermined directions that intersect at right angles in a horizontal plane will be referred to as the "X direction" and the "Y direction". Furthermore, one of the X directions will be referred to as the "X- direction" and the opposite direction will be referred to as the "X+ direction". Furthermore, one of the Y directions will be referred to as the "Y- direction" and the opposite direction will be referred to as the "Y+ direction".

[0031] 1, the case 80 has a box shape that opens upward. The case 80 is made of a material such as metal. The case 80 houses the battery cells 70, the bus bars 50, and the cooling members 40. The cover 30 covers the opening of the case 80.

[0032] As shown in Fig. 3, each battery cell 70 has a rectangular exterior that is elongated in the X direction. Hereinafter, a plurality of battery cells 70 stacked in the Y direction will be referred to as a "battery stack Bs." The case 80 houses two battery stacks Bs aligned in the X direction. In each battery stack Bs, a separator 79 is disposed between every two battery cells 70 aligned in the Y direction. The separator 79 is made of a material such as resin.

[0033] 3, each battery cell 70 has a positive electrode p at one end in the X direction on the top surface of the exterior, and a negative electrode n at the other end in the X direction on the top surface of the exterior 72. Specifically, for a certain number of battery cells 70, the positive electrode p is arranged on the X- direction side, and the negative electrode n is arranged on the X+ direction side. On the other hand, for the other battery cells 70, the negative electrode n is arranged on the X- direction side, and the positive electrode p is arranged on the X+ direction side.

[0034] 2, most of the bus bars 50 electrically connect the electrodes p, n of the battery cells 70 adjacent in the X direction or the Y direction. On the other hand, a given bus bar 50 electrically connects the positive electrode p of the battery cell 70 that is electrically the most positive to the positive electrode P of the entire battery module 100. Another bus bar 50 electrically connects the negative electrode n of the battery cell 70 that is electrically the most negative to the negative electrode N of the entire battery module 100. As described above, in this embodiment, all of the battery cells 70 in the battery module 100 are connected in series.

[0035] 6, each bus bar 50 is formed, for example, by bending a single metal plate. An inserted portion 55 is provided on each bus bar 50 directly above the portion that abuts against electrodes p, n.

[0036] Specifically, as shown in FIG. 4, each busbar 50 has a busbar base 52 and a return portion 54. The busbar base 52 is a plate extending in the X and Y directions. The return portion 54 is provided for each electrode p, n. For example, as shown in FIG. 4, each return portion 54 may have a shape that extends downward from an end of the busbar base 52 in the Y direction and then extends inward in the Y direction, or a different shape that extends downward from an end of the X direction and then extends inward in the X direction. The return portions 54 are welded to the electrodes p, n. A through hole 53 is formed in a portion of the busbar base 52 located directly above the electrodes p, n. The portion from the through hole 53 to the return portion 54 constitutes the inserted portion 55. Therefore, the back surface of the portion of the return portion 54 that abuts against the electrodes p, n constitutes the bottom surface of the inserted portion 55.

[0037] 1, a cooling member 40 is provided for each bus bar 50. Each cooling member 40 is in contact with the upper surface of the bus bar 50 corresponding to the cooling member 40 so as to be capable of conducting heat therethrough. Each cooling member 40 is made of rubber having thermal conductivity and insulating properties, and more specifically, is made of EPDM rubber (ethylene propylene diene rubber).

[0038] As shown in Fig. 6, each cooling member 40 has a cooling member base 42, an insulating portion 47, and a protrusion 45. As shown in Fig. 5, the cooling member base 42 is plate-shaped extending in the X and Y directions. The insulating portions 47 protrude downward from both ends of the cooling member base 42 in the Y direction. As shown in Fig. 4, a protrusion 45 is provided for each of the electrodes p and n. Each protrusion 45 protrudes downward from the cooling member base 42. Each protrusion 45 is inserted into a corresponding inserted portion 55 and abuts against the bottom of the inserted portion 55.

[0039] 5, the insulating portion 47 on the Y+ side of each cooling member 40 abuts against the end of the bus bar 50 on the Y+ direction side from the Y+ direction. The insulating portion 47 on the Y- side of each cooling member 40 abuts against the end of the bus bar 50 on the Y- direction side from the Y- direction side. As a result, insulating portions 47, which are part of the cooling member 40, are present between the bus bars 50 adjacent in the Y direction. As shown in FIG. 4, the upper surface of the cooling member base 42 abuts against the lower surface of the cover 30.

[0040] With the above configuration, heat from each battery cell 70 is dissipated from the electrodes p and n through the bus bars 50 and the cooling member 40 to the cover 30, as shown in FIG.

[0041] The configuration and effects of this embodiment are summarized below.

[0042] 4, the cooling member 40 is in heat-transferable contact with the rear side of the bus bar 50 at the portion that contacts the electrodes p, n. This allows heat transferred from the electrodes p, n of the battery cell 70 to the bus bar 50 to be dissipated to the cooling member 40 located on the rear side of the electrodes p, n. This allows the battery cell 70 to be cooled efficiently.

[0043] An inserted portion 55 is provided on the back side of the portion of the busbar 50 that abuts against the electrodes p, n. The protrusions 45 of the cooling member 40 are inserted into the inserted portions 55. This allows the cooling member 40 to be positioned with respect to the busbar 50. Moreover, the protrusions 45 of the cooling member 40 abut against the bottom of the inserted portions 55, i.e., against the back side of the portion of the busbar 50 that abuts against the electrodes p, n. This allows the heat transferred from the electrodes p, n to the busbar 50 to be dissipated to the protrusions 45 of the cooling member 40 that are located on the back side of the electrodes p, n.

[0044] Cooling member 40 is made of rubber, and therefore can absorb variations in height of busbar 50 within the elastic range of rubber.

[0045] The upper surface of the cooling member 40, i.e., the surface of the cooling member 40 opposite the bus bar 50 side, abuts against the cover 30. Therefore, 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. As a result, the battery cells 70 can be cooled more efficiently.

[0046] Cooling member 40 is made of rubber that has thermal conductivity and insulation properties. Therefore, cooling member 40 can ensure insulation between bus bar 50 and cover 30 while ensuring thermal conductivity between bus bar 50 and cover 30.

[0047] More specifically, the cooling member 40 is made of EPDM rubber. The EPDM rubber has heat conductivity and insulation properties. Therefore, the heat conductivity and insulation properties between the bus bar 50 and the cover 30 can be ensured by the EPDM rubber.

[0048] Insulating portion 47, which is a part of cooling member 40, is present between adjacent bus bars 50. Therefore, insulation between adjacent bus bars 50 can be ensured by utilizing cooling member 40.

[0049] As shown in FIG. 6, the busbar 50 is provided with an insertion portion 55. The cooling member 40 has protrusions 45 that are inserted into the insertion portion 55. In other words, the busbar 50 and the cooling member 40 have uneven shapes that fit together. This makes it possible to prevent the cooling member 40 from shifting in position relative to the busbar 50. As a result, as shown in FIG. 4, the cooling member 40 can be held in an optimal position relative to the busbar 50, maximizing heat dissipation performance. Therefore, in this respect as well, the battery cells 70 can be efficiently cooled.

[0050] [Second embodiment] Next, a second embodiment will be described with reference to Fig. 7. The present embodiment will be described based on the first embodiment, focusing on the differences therebetween, and descriptions of the same or similar aspects as the first embodiment will be omitted as appropriate.

[0051] 7, the water jacket 20 is attached above the cover 30, that is, on the outside of the cover 30. The space between the water jacket 20 and the cover 30 forms a flow path Fp. A refrigerant Rf flows through the flow path Fp.

[0052] According to this embodiment, the refrigerant Rf flows between the water jacket 20 and the cover 30. Therefore, the heat of the battery cells 70 that is dissipated from the electrodes p, n to the cover 30 via the bus bar 50 and the cooling member 40 can be further dissipated to the refrigerant Rf. As a result, the battery cells 70 can be cooled even more efficiently.

[0053] [Other embodiments] The above-described embodiment can be modified, for example, as follows. The cooling member 40 shown in FIG. 4 may be a rubber other than EPDM rubber. Specifically, for example, it may be a rubber made of silicone with good thermal conductivity. The case 80 shown in FIG. 3 may house only one battery stack Bs, or may house three or more. In the case 80 shown in FIG. 2, a plurality of parallel-connected bodies of a predetermined number of battery cells 70, such as two or three, may be connected in series. Some of the plurality of cooling members 40 may be integrally formed. In other words, one cooling member 40 may be provided so as to straddle a plurality of bus bars 50. [Explanation of symbols]

[0054] 20 Water Jacket 30 Cover 40 Cooling material 45 Protrusion (uneven shape) 47 Insulation part (part of cooling member) 50 Busbar 55 Inserted part (uneven shape) 70 Battery Cells 80 cases 100 Battery Module Fp flow passage (between water jacket and cover) Rf refrigerant

Claims

1. A plurality of battery cells; One or more bus bars electrically connecting electrodes of the plurality of battery cells to each other; a cooling member in contact with a rear side of the bus bar at a portion where the bus bar is in contact with the electrode, so as to be capable of conducting heat therethrough; A battery module comprising:

2. an insertion portion is provided on a rear 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 of the inserted portion. The battery module according to claim 1 .

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

4. a case that houses the battery cells, the bus bars, and the cooling member; a cover for covering the opening of the case, a surface of the cooling member opposite to the bus bar side abuts against a cover; The battery module according to claim 3 .

5. The battery module according to claim 3 , wherein the cooling member is made of rubber having thermal conductivity and insulating properties.

6. The battery module according to claim 5 , wherein the rubber is an EPDM rubber.

7. A plurality of the bus bars are provided, A part of the cooling member is present between adjacent bus bars. The battery module according to claim 5 .

8. A water jacket is attached to the outside of the cover, A refrigerant flows between the water jacket and the cover. The battery module according to claim 4 .

9. The bus bar and the cooling member have projections and recesses that fit together. The battery module according to claim 1 or 2.

10. A plurality of battery cells; One or more bus bars electrically connecting electrodes of the plurality of battery cells to each other; a cooling member in contact with the bus bar so as to be capable of transferring heat thereto; The bus bar and the cooling member have projections and recesses that fit together. Battery module.

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