Battery device

Abstract

To provide a battery device capable of improving cooling performance of a battery cell.SOLUTION: A battery device includes a wall, a plurality of battery cells, and an opposing surface. A flow path through which a cooling fluid flows is provided inside the wall. The plurality of battery cells are stacked along the wall. The opposing surface faces the wall that is provided over a side surface of the plurality of battery cells. The opposing surface has a battery cell recess. The wall has a protrusion that is received in a battery cell recess and directly or indirectly connected to the battery cell recess.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a battery device. [Background technology]

[0002] Conventionally, there are battery devices that include multiple battery cells and a structure for cooling the multiple battery cells. For example, a device is known in which a heat sink is provided in part of multiple beam frames that separate multiple battery modules (for example, Patent Document 1). Also known is a device in which a cooling protrusion is disposed between adjacent battery cells (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2019-536241 [Patent Document 2] International Publication No. 2019 / 150705 Summary of the Invention [Problem to be solved by the invention]

[0004] In this type of battery device, for example, improved cooling performance is required.

[0005] Therefore, one object of the present invention is to provide a battery device that can improve the cooling performance of battery cells. [Means for solving the problem]

[0006] The battery device of the present invention comprises a wall having a flow path formed therein through which a cooling fluid flows, a plurality of battery cells stacked along the wall, and an opposing surface extending along the side surfaces of the plurality of battery cells and facing the wall, the opposing surface having a battery cell recess, and the wall having a protrusion inserted into the battery cell recess and directly or indirectly connected to the battery cell recess.

[0007] With this configuration, the side surfaces of the battery cells can be cooled, thereby improving the cooling performance of the battery cells.

[0008] The battery device includes, for example, a flexible heat-conducting member that is interposed between the wall and the opposing surface and directly or indirectly connects the wall and the opposing surface.

[0009] This configuration can prevent gaps from forming between the wall and the opposing surface, improving heat exchange between the wall and the battery cells, thereby further improving the cooling of the battery cells. [Effects of the Invention]

[0010] According to the present invention, a battery device that can improve the cooling performance of battery cells can be obtained. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is an exploded perspective view showing a battery device according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a battery device according to the present invention will be described in detail with reference to the drawings.

[0013] The drawings are schematic, and the dimensional relationships and ratios of elements may differ from reality. Furthermore, the drawings may contain parts in which the dimensional relationships and ratios differ from one another.

[0014] Fig. 1 is an exploded perspective view showing a battery device according to an embodiment. The battery device 1 shown in Fig. 1 is mounted on a vehicle, such as an electric vehicle powered by a motor or a hybrid vehicle powered by an internal combustion engine and a motor, and is used as a power source for the vehicle.

[0015] As shown in each drawing, for convenience, the X-axis, Y-axis, and Z-axis are defined in this specification. The X-axis, Y-axis, and Z-axis are perpendicular to each other. The X-axis is, for example, along the longitudinal direction of the battery device 1. The Y-axis is along the lateral direction of the battery device 1. The Z-axis is along the vertical direction of the battery device 1.

[0016] Furthermore, in this specification, the X direction, Y direction, and Z direction are defined. The X direction is a direction along the X axis, and includes the +X direction indicated by the X axis arrow and the -X direction opposite to the X axis arrow. The Y direction is a direction along the Y axis, and includes the +Y direction indicated by the Y axis arrow and the -Y direction opposite to the Y axis arrow. The Z direction is a direction along the Z axis, and includes the +Z direction indicated by the Z axis arrow and the -Z direction opposite to the Z axis arrow. The +Z direction is, for example, along the upward direction of the battery device 1.

[0017] The battery device 1 includes a case 2 and a plurality of stacked battery cell units 3 (a plurality of battery cells 21). The plurality of stacked battery cell units 3 are connected in series or parallel.

[0018] The case 2 is formed in the shape of a flat, approximately rectangular parallelepiped. The case 2 includes, for example, a case body 11 and a lid 12. The case body 11 and the lid 12 are made of, for example, aluminum. A storage chamber that houses multiple stacked battery cell units 3 is provided inside the case body 11. The lid 12 is fixed to the case body 11 with fasteners such as screws, and closes the storage chamber of the case body 11.

[0019] The case body 11 has, for example, a plurality of outer walls 11a, 11c, 11d, 11e, and 11f and a plurality of partition walls 11g.

[0020] Outer wall 11a is the wall on the lower side (-Z direction side) in the up-down direction of case 2. Outer wall 11c is the wall on the -X direction side of case 2. Outer wall 11d is the wall on the +X direction side of case 2. Outer wall 11e is the wall on the -Y direction side of case 2. Outer wall 11f is the wall on the +Y direction side of case 2. Outer wall 11c, outer wall 11d, outer wall 11e, and outer wall 11f each extend upward from outer wall 11a.

[0021] The partition walls 11g are arranged between the outer walls 11c and 11d at intervals in the X direction. The partition walls 11g span the outer walls 11e and 11f. The partition walls 11g also extend upward from the outer wall 11a. The partition walls 11g divide the storage chamber of the case 2 into multiple regions (chambers), and each region houses one stacked battery cell unit 3. The partition walls 11g, the outer walls 11c, and the outer walls 11d each correspond to a "wall." Note that the "wall" may refer to any one of the partition walls 11g, the outer walls 11c, and the outer walls 11d.

[0022] As can be seen from the above, partition wall 11g, outer wall 11c, and outer wall 11d are arranged at intervals in the X direction and extend over outer wall 11e and outer wall 11f, respectively. Hereinafter, partition wall 11g, outer wall 11c, and outer wall 11d are collectively referred to as wall 11h. Wall 11h suppresses deformation of the battery pack 1, for example, when a vehicle collides in the Y direction. Wall 11h is also referred to as a side wall, beam frame, load path, or buffer member.

[0023] The case body 11 is provided with a cooling flow path 14 through which a cooling fluid flows. The cooling fluid is, for example, but not limited to, cooling water or oil. The cooling fluid may be liquid or gas.

[0024] The cooling flow path 14 is provided across the outer wall 11c, the outer wall 11d, the outer wall 11e, the outer wall 11f, and the multiple partition walls 11g. The cooling flow path 14 has an inlet 14a and an outlet 14b. The inlet 14a and the outlet 14b are provided in the outer wall 11c. Although the inlet 14a and the outlet 14b are provided in the outer wall 11c, the location of the inlet 14a and the outlet 14b is not limited to the outer wall 11c. The cooling fluid flows into the cooling flow path 14 from the inlet 14a, passes from the outer wall 11c through the outer wall 11e, flows into the multiple partition walls 11g and the outer wall 11d, and flows through the multiple partition walls 11g and the outer wall 11d. After flowing through the multiple partition walls 11g and the outer wall 11d, the cooling fluid returns to the outer wall 11c through the outer wall 11f and flows out from the outlet 14b. In Figure 1, the flow direction of the cooling fluid is indicated by arrows. The stacked battery cell unit 3 is cooled by the cooling fluid flowing as described above. The cooling fluid is cooled by a heat exchanger such as a radiator. The radiator is disposed, for example, facing one of the outer walls 11c, 11d, 11e, and 11f. Note that the location of the radiator is not limited to the above. The cooling flow path 14 is also referred to as a flow path or a passage.

[0025] Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. As shown in Fig. 2, two flow paths 14c and a hollow portion 15 are provided inside the partition wall 11g. The two flow paths 14c are included in the cooling flow path 14. The two flow paths 14c and the hollow portion 15 penetrate the partition wall 11g in the longitudinal direction, i.e., in the lateral direction (Y direction) of the case body 11.

[0026] Both ends of the hollow portion 15 are closed by the outer wall 11e and the outer wall 11f. In other words, the hollow portion 15 is a closed space. Air is placed inside the hollow portion 15. In the X direction, the hollow portion 15 is provided between the two flow paths 14c and functions as a heat insulating portion that insulates the space between the two flow paths 14c. The larger the size of the hollow portion 15, the greater the heat insulating effect. The partition wall 11g is, for example, an extruded member made of aluminum. The hollow portion 15 is also called a cast portion.

[0027] The partition wall 11g has a lower surface 11ga, an upper surface 11gb, and two side surfaces 11gc. The two side surfaces 11gc extend between the lower surface 11ga and the upper surface 11gb.

[0028] Each side surface 11gc is provided with a plurality of protrusions 11gd and a plurality of recesses 11ge. The protrusions 11gd and recesses 11ge are alternately provided in the vertical direction (Z direction). The protrusions 11gd and recesses 11ge form an uneven portion.

[0029] Here, like the partition wall 11g, the inner surfaces (inner side surfaces) of the outer walls 11c and 11d are also provided with convex portions 11gd and concave portions 11ge. That is, each wall 11h is provided with convex portions 11gd and concave portions 11ge.

[0030] As shown in FIG. 2, the stacked battery cell unit 3 has a plurality of battery cells 21 and an opposing surface 3a.

[0031] The plurality of battery cells 21 are connected in series or parallel. The plurality of battery cells 21 are stacked in the vertical direction (Z direction) along the partition wall 11g. The battery cells 21 are, for example, laminated lithium ion secondary batteries. The battery cells 21 may also be secondary batteries such as nickel-metal hydride batteries. The battery cells 21 are also called laminated cells.

[0032] Each battery cell 21 has a bottom surface 21a, a top surface 21b, and two side surfaces 21c. Note that Fig. 2 shows one of the two side surfaces 21c of each battery cell 21. In the vertical direction (Z direction), the two side surfaces 21c extend between the bottom surface 21a and the top surface 21b.

[0033] Each side surface 21c is formed in a convex shape that faces the outside of the battery cell 21 (either one of the partition wall 11g, the outer wall 11c, or the outer wall 11d). Specifically, the side surface 21c has two slopes: an upper slope 21ca and a lower slope 21cb. The upper slope 21ca is located above the lower slope 21cb. The upper slope 21ca and the lower slope 21cb approach each other as they move toward the outside of the battery cell 21 (either one of the partition wall 11g, the outer wall 11c, or the outer wall 11d).

[0034] The opposing surface 3a of the stacked battery cell unit 3 includes the side surfaces 21c of the multiple battery cells 21. The opposing surface 3a is provided across the side surfaces 21c of the multiple battery cells 21 and faces the side surface 11gc of the partition wall 11g.

[0035] The opposing surface 3a has a plurality of battery cell protrusions 3b and a plurality of battery cell recesses 3c. The battery cell protrusions 3b and the battery cell recesses 3c are arranged alternately in the vertical direction (Z direction). The battery cell protrusions 3b and the battery cell recesses 3c form an uneven portion. Each battery cell protrusion 3b is formed by the side surface 21c of a battery cell 21. Each battery cell recess 3c is formed by the lower slope 21cb of the upper battery cell 21 and the upper slope 21ca of the lower battery cell 21 of two battery cells 21 adjacent in the vertical direction.

[0036] The battery cell protrusions 3b on the opposing surface 3a fit into the recesses 11ge of the wall 11h and are indirectly or directly connected to the recesses 11ge. The battery cell protrusions 3b are thermally connected to the recesses 11ge. The battery cell recesses 3c on the opposing surface 3a fit into the protrusions 11gd of the wall 11h and are indirectly or directly connected to the battery cell recesses 3c and the protrusions 11gd. The battery cell recesses 3c and the protrusions 11gd are thermally connected. In other words, the unevenness on the opposing surface 3a of the stacked battery cell unit 3 and the unevenness on the side surface 11gc of the partition wall 11g overlap.

[0037] A thermally conductive member 16 is provided between the stacked battery cell unit 3 and the wall 11h. The thermally conductive member 16 is flexible and is interposed between the wall 11h and the opposing surface 3a, directly or indirectly connecting the wall 11h and the opposing surface 3a. The thermally conductive member 16 thermally connects the wall 11h and the opposing surface 3a. The thermally conductive member 16 is interposed at least between the battery cell protrusion 3b on the opposing surface 3a and the recess 11ge of the wall 11h, and between the battery cell recess 3c on the opposing surface 3a and the protrusion 11gd of the wall 11h. The thermally conductive member 16 is, for example, a heat-dissipating gel. Note that the thermally conductive member 16 is not limited to the above. The thermally conductive member 16 is also referred to as a connecting member.

[0038] In the battery device 1 configured as described above, the cooling fluid cools the stacked battery cell unit 3 (battery cells 21) as it passes through the flow paths 14c provided in the wall 11h. Specifically, the wall 11h exchanges heat between the cooling fluid and the stacked battery cell unit 3 via the heat-conducting member 16.

[0039] As described above, the battery device 1 of this embodiment includes a wall 11h and a stacked battery cell unit 3. The wall 11h has a flow path 14c inside it through which a cooling fluid flows. The stacked battery cell unit 3 has a plurality of battery cells 21 stacked along the wall 11h and an opposing surface 3a that faces the wall 11h and is provided across the side surfaces 21c of the plurality of battery cells 21. The opposing surface 3a has a battery cell recess 3c. The wall 11h has a protrusion 11ca that is inserted into the battery cell recess 3c and is directly or indirectly connected to the battery cell recess 3c.

[0040] With this configuration, the side surface 21c of the battery cell 21 can be cooled, thereby improving the cooling performance of the battery cell 21. Here, for example, in a laminated battery cell 21, the side surface 21c becomes hotter than the bottom surface 21a and the top surface 21b. Therefore, by cooling the side surface 21c as described above, the battery cell 21 can be cooled efficiently. Furthermore, with the above configuration, the wall 11h can increase the rigidity of the battery device 1, thereby improving impact resistance and noise and vibration suppression performance (NV performance). Note that the multiple battery cells 21 (stacked battery cell unit 3) may be mounted in a vehicle as is, or may be modularized and mounted in a vehicle as a battery pack.

[0041] The battery device 1 also includes, for example, a heat conductive member 16. The heat conductive member 16 is flexible and is interposed between the wall 11h and the opposing surface 3a to directly or indirectly connect the wall 11h and the opposing surface 3a.

[0042] This configuration can prevent gaps from forming between the wall 11h and the opposing surface 3a, improving heat exchange between the wall 11h and the battery cells 21. This further improves the cooling of the battery cells 21.

[0043] While the above describes exemplary embodiments of the present invention, the above embodiments are merely examples and are not intended to limit the scope of the invention. The above embodiments may be implemented in various other forms, and various omissions, substitutions, combinations, and modifications may be made without departing from the spirit of the invention. The above embodiments are within the scope and spirit of the invention, as well as the scope of the inventions and their equivalents set forth in the claims. The present invention may be realized using configurations other than those disclosed in the above embodiments, and various effects (including derivative effects) obtained from the basic configuration (technical features) may be obtained. Furthermore, the specifications of each component (structure, type, direction, shape, size, length, width, thickness, height, number, arrangement, position, material, etc.) may be modified as appropriate. [Explanation of symbols]

[0044] 1...battery device, 3a...opposing surface, 3c...battery cell recess, 11ca...protrusion, 11h...wall, 14c...flow path, 16...thermal conductive member, 21...battery cell, 21c...side surface.

Claims

1. a wall having a flow path therein through which a cooling fluid flows; a plurality of battery cells stacked along the wall; an opposing surface that is provided across a side surface of the plurality of battery cells and faces the wall; Equipped with the opposing surface has a battery cell recess; the wall has a protrusion that is inserted into the battery cell recess and is directly or indirectly connected to the battery cell recess; battery device.

2. a heat conduction member that is flexible and is interposed between the wall and the opposing surface to directly or indirectly connect the wall and the opposing surface; The battery device according to claim 1 .

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