Power storage module and power storage device

Abstract

A power storage module (20) comprises a first stack (21) and a second stack (22) arranged alternately next to each other in a first direction, wherein the first stack (21) comprises a plurality of first unit cells (211) arranged in the first direction, and the second stack (22) comprises a plurality of second unit cells (212) arranged in a height direction orthogonal to the first direction

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This non-provisional application is based on Japanese Patent Application No. 2024-009922 filed with the Japan Patent Office on January 26, 2024, the entire contents of which are hereby incorporated by reference. BACKGROUND area

[0002] The present invention relates to a power storage module and a power storage device including the power storage module. Description of the state of the art

[0003] As a conventional power storage module, WO 2020 / 134054A1 discloses a configuration in which a plurality of unit cells are arranged side by side in a specific direction. SUMMARY

[0004] In the configuration where the plurality of unit cells are arranged side by side in one direction, as disclosed in WO 2020 / 134054 A1, the side surfaces of the unit cells each having the largest area are arranged side by side in a first direction. When a particular unit cell generates heat, one side surface thereof expands in the first direction, and the heat is transferred to the unit cells sequentially from the side closer to the first unit cell that generated the heat to the side farther from the first unit cell. Therefore, there is a concern that the heat is transferred to the plurality of unit cells over a wide range in the first direction.

[0005] The present invention has been made in view of the above-described problem, and an object of the present invention is to provide a power storage module capable of suppressing heat transfer to the entire power storage module when a certain unit cell generates heat, and a power storage device including the power storage module.

[0006] A power storage module according to the present invention comprises a first stack and a second stack arranged alternately next to each other in a first direction. The first stack contains a plurality of first unit cells arranged in the first direction. The second stack contains a plurality of second unit cells arranged in a height direction orthogonal to the first direction.

[0007] In general, when a unit cell generates heat, a central portion (antinode) of the unit cell expands, and the heat is transferred to a unit cell adjacent to that unit cell.

[0008] According to the above-described configuration, since the first stack and the second stack, which differ in stacking direction, are alternately arranged, a direction of the antinodes of the first unit cells included in the first stack can be made different from a direction of the antinodes of the second unit cells included in the second stack. This can suppress heat transfer between the first stack and the second stack.

[0009] In the power storage module according to the present invention, in which the first stack and the second stack are alternately arranged in the first direction, the first stack may be arranged at each of the two ends in the first direction.

[0010] According to the configuration described above, since the first stack in which the antinodes of the first unit cells are arranged in the first direction is arranged at each of the two ends in the first direction, heat is likely to escape to the outside in the first direction.

[0011] A power storage device of the present invention comprises: the power storage module described above; and a cooler that cools the first stack and the second stack.

[0012] According to the configuration described above, the first stack and the second stack can be cooled by the cooler.

[0013] In the power storage device according to the present invention, the cooler may be provided so as to extend in the first direction while passing through a gap between the first stack and the second stack and meander (meander-arranged) in the height direction.

[0014] According to the above-described configuration, since the cooler is configured to extend in the first direction while meandering in the height direction, an upward-facing or downward-facing surface of the second unit cells included in the second stack can be cooled in the height direction in the stacked state. Furthermore, a surface of the first unit cells facing either side in the first direction can also be cooled by the cooler.

[0015] In the power storage device according to the invention described above, each of the first stack and the second stack may include a plurality of side surfaces arranged around an axis orthogonal to the first direction and the height direction. In this case, the cooler may be arranged in a meandering pattern to cool two side surfaces of the plurality of side surfaces of the first stack and two side surfaces of the plurality of side surfaces of the second stack.

[0016] According to the configuration described above, the first stack and the second stack can be cooled substantially evenly because the cooler is arranged in a meandering pattern. This can suppress the occurrence of heat dispersion between the first stack and the second stack.

[0017] The above object and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view of a vehicle with a power storage device according to a first embodiment. Fig. 2 shows a state in which the power storage device according to the first embodiment is mounted on the vehicle. Fig. 3 is a schematic exploded perspective view of the power storage device according to the first embodiment. Fig. 4 is a schematic perspective view showing a power storage module and a cooler in the power storage device according to the first embodiment. Fig. 5 is a schematic view showing the movement of heat when a certain unit cell generates the heat in the power storage module according to the first embodiment. Fig. 6 is a schematic view showing the movement of heat when a certain unit cell generates heat in a power storage module according to a comparative embodiment. Fig. 7 is a schematic view of a power storage module and a cooler in a power storage device according to a second embodiment, when viewed from a side in a second direction. Fig. 8 is a schematic plan view of the power storage module and the cooler in the power storage device according to the second embodiment when viewed from above. DESCRIPTION OF PREFERRED EMBODIMENTS

[0018] Embodiments of the present invention will be described in detail below with reference to the drawings. In the embodiments described below, the same or corresponding portions in the drawings are designated by the same reference numerals, and their descriptions will not be repeated. (First embodiment)

[0019] Fig. 1 is a schematic view of a vehicle having a power storage device according to a first embodiment. Fig. Fig. 2 shows a state in which the power storage device according to the first embodiment is mounted on the vehicle. A vehicle 1 according to the first embodiment is described with reference to Fig. Fig. 1 and Fig. 2 described.

[0020] The vehicle 1 is a hybrid vehicle that can move using the drive power of at least one electric motor or an internal combustion engine, or an electrically powered vehicle that moves using a drive power obtained from electric current.

[0021] The vehicle 1 includes a vehicle main body 2, a front wheel 3, a rear wheel 4, and an energy storage device 10. The vehicle main body 2 includes a frame member 5. The energy storage device 10 has an upper surface 10a. The upper surface 10a also functions as a floor member that defines a vehicle interior.

[0022] The frame member 5 includes a pair of side members 6 and a pair of side sills 7. The two side sills 7 are arranged at both ends in the width direction of the vehicle 1. The two side members 6 are arranged inside the two side sills 7 with a gap therebetween. The two side members 6 and the two side sills 7 extend along a longitudinal direction of the vehicle 1.

[0023] The two side elements 6 are spaced apart from each other in the width direction of the vehicle 1. A main body portion 35 of the power storage device 10 is arranged in a gap between the two side elements 6. A cavity is provided between the main body portion 35 and the two side elements 6. This suppresses the transmission of the impact to the power storage device 10, even in the event of a side impact of the vehicle 1.

[0024] On both side surfaces of the main body portion 35, fixed portions 36 are provided in the width direction of the vehicle 1. The fixed portions 36 are each fixed to the pair of side members 6 by fixing members 8.

[0025] The frame member 5 also includes a cross member 9. The cross member 9 is provided above the power storage device 10 to extend from one side sill 7 to the other side sill 7. The upper surface 10a of the power storage device 10 is attached to the cross member 9.

[0026] Although the example in which the frame member 5 includes the pair of side members 6 and the pair of side sills 7 has been illustrated and described above, the present invention is not limited thereto. The pair of side sills 7 may function as the pair of side members 6. In this case, the pair of side members 6 may be omitted, and the above-described fixed portions 36 may be fixed to the pair of side sills 7.

[0027] Fig. Fig. 3 is a schematic exploded perspective view of the power storage device according to the first embodiment. A detailed configuration of the power storage device 10 will be described with reference to Fig. 3 described.

[0028] The power storage 10 comprises a plurality of power storage modules 20, a receiving housing 30, a separating element 40 and a cooler 50 (see Fig. 4).

[0029] The plurality of power storage modules 20 are arranged side by side in a second direction (DR2 direction) that is orthogonal to the first direction (DR1 direction) and the height direction. The height direction is orthogonal to the first direction. The first direction is, for example, parallel to a left-right direction of the vehicle 1 in an installed state in which the power storage device 10 is mounted on the vehicle 1. The second direction is parallel to the front-rear direction of the vehicle 1 in the installed state described above. The height direction is parallel to a vertical direction and is parallel to the height direction of the vehicle 1.

[0030] Each of the power storage modules 20 includes a plurality of unit cells. A busbar module is provided on each side of the power storage module 20 in the first direction, and the plurality of unit cells are connected in series by the busbar modules. The plurality of power storage modules 20 are also connected in series.

[0031] The receiving case 30 includes an upper member 31 and a lower member 32. The lower member 32 has a substantially box-like shape that opens upward. The lower member 32 includes a main body portion 35 and fixed portions 36. The main body portion 35 has a bottom wall portion 321, a first wall portion 322, a second wall portion 323, and side wall portions 324 and 325. The first wall portion 322, the second wall portion 323, and the side wall portions 324 and 325 are provided so as to rise from a peripheral edge of the bottom wall portion 321.

[0032] The first wall portion 322 and the second wall portion 323 face each other in the second direction. The side wall portions 324 and 325 face each other in the first direction. The fixed portions 36 are provided on the outer surfaces of the side wall portions 324 and 325.

[0033] The separating element 40 serves to divide a receiving space in the receiving housing 30. In particular, the separating element 40 is provided such that it extends in the first direction and divides the receiving space in the receiving housing 30 in the second direction. The separating element 40 divides an area in which the power storage modules 20 are arranged. A power storage module 20 is arranged in each area divided by the separating element 40.

[0034] The upper member 31 has a substantially flat plate shape. The upper member 31 covers the plurality of power storage modules 20 and closes an open space of the lower member 32. A sealing member may be filled into a gap between the upper member 31 and the power storage modules 20. The sealing member may have insulating properties.

[0035] Fig. 4 is a schematic perspective view showing the power storage module and the cooler in the power storage device according to the first embodiment.

[0036] As in Fig. As shown in Figure 4, the power storage module 20 includes a plurality of first stacks 21 and a plurality of second stacks 22. The number of the first stacks 21 and the second stacks 22 can be adjusted accordingly depending on the size of the vehicle 1. The number of the first stacks 21 and the second stacks 22 is not limited to two or more and may be only one.

[0037] The plurality of first stacks 21 and the plurality of second stacks 22 are arranged alternately in the first direction. Each of the first stacks 21 includes a plurality of first unit cells 211 arranged in the first direction. Each of the second stacks 22 includes a plurality of second unit cells 212 arranged in the height direction.

[0038] Each of the first unit cells 211 and the second unit cells 212 has an elongated shape, with the second direction being a longitudinal direction. Each of the first unit cells 211 has a flat rectangular parallelepiped shape with a thickness in the first direction. Each of the second unit cells 212 has a flat rectangular parallelepiped shape with a thickness in the height direction.

[0039] Each of the first unit cells 211 and each of the second unit cells 212 can be configured using the same unit cell. In this case, the number of components can be reduced and the manufacturing cost can be lowered. It should be noted that "the same" includes a unit cell with manufacturing errors such as tolerances. Alternatively, each of the first unit cells 211 and each of the second unit cells 212 can be configured using different unit cells.

[0040] Each of the first unit cells 211 and the second unit cells 212 is, for example, a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. Each of the first unit cells 211 and the second unit cells 212 may be a liquid electrolyte unit cell or a solid electrolyte unit cell. Each of the first unit cells 211 and the second unit cells 212 may be a chargeable and dischargeable capacitor.

[0041] Each of the first unit cells 211 and the second unit cells 212 has a first end face and a second end face on one side and the other side in the second direction. The first end face of each of the first unit cells 211 and the second unit cells 212 faces the above-described sidewall portion 324. The second end face of each of the first unit cells 211 and the second unit cells 212 faces the above-described sidewall portion 325.

[0042] The first stacks 21 are arranged at both ends of the power storage module 20 in the first direction. That is, in the first stacks 21 and second stacks 22 arranged alternately in the first direction, the first stacks 21 are arranged at both ends in the first direction. In such a case, a central portion (antinode) of a side surface of the first unit cell 211 having the largest area, as described below, is exposed to a gap between the first unit cell 211 and the sidewall portion 324, 325, and thus heat is likely to escape to the outside in the first direction. This can improve the heat dissipation performance of the power storage module 20.

[0043] The cooler 50 is arranged, for example, below the power storage module 20. The cooler 50 is provided for cooling the power storage module 20. In particular, a refrigerant flow path through which refrigerant flows to cool the power storage module 20 is provided in the cooler 50. The cooler 50 has a shape that extends in a plane direction orthogonal to the height direction. The cooler 50 can be arranged above the power storage module 20.

[0044] The cooler 50 may be in direct contact with the power storage module 20 or may be in thermal contact with the power storage module 20 via a thermally conductive element with high thermal conductivity. The thermally conductive element may be an adhesive containing a silicone-based resin, an acrylic resin, a urethane resin, or an epoxy resin.

[0045] Fig. 5 is a schematic view showing the movement of heat when a certain unit cell generates heat in the power storage module according to the first embodiment.

[0046] As in Fig. As shown in Figure 5, in each of the first stacks 21, the side surfaces of the first unit cells 211, each having the largest area, are arranged in the first direction. On the other hand, in each of the second stacks 22, the side surfaces of the second unit cells 212, each having the largest area, are arranged in the height direction.

[0047] When a unit cell generates heat, a central part (antinode) of a side surface with the largest area expands in the thickness direction (the first direction in the first unit cell 211 and the height direction in the second unit cell 212), and the heat is transferred to a unit cell arranged adjacent to this unit cell.

[0048] In the present embodiment, first stacks 21 and second stacks 22 different in stacking direction are alternately arranged, and thus a direction of antinodes of the first unit cells 211 included in the first stacks 21 may be different from a direction of antinodes of the second unit cells 212 included in the second stacks 22.

[0049] Therefore, when the specified first unit cell 211 in the first stack 21 generates heat (when heat is generated at a position indicated by "F" in the figure), the heat is transferred as shown by the arrow AR1 in this first stack 21. However, the antinode of the first unit cell 211 located at each of the two ends in the first direction does not come close to the antinode of the second unit cell 212 in the second stack 22, but approaches the side surface of the second unit cell 212 with a small area. As a result, heat transfer from the first stack 21 to the second stack 22 is suppressed. In addition, since the antinode of the second stack 22 faces in the height direction, heat is less likely to be transferred from the second stack 22 to the first unit cell 211 located opposite the first stack 21, including the first unit cell 211 that generated the heat.In this way, the heat transfer between the first stacks 21 and the second stacks 22 can be suppressed, and the heat transfer to the entire power storage module 20 can be suppressed. (Comparative embodiment)

[0050] Fig. 6 is a schematic view showing the movement of heat when a particular unit cell generates heat in a power storage module according to a comparative embodiment. The movement of heat in a power storage module 20X according to the comparative embodiment will be described with reference to Fig. 6 described.

[0051] As in Fig. As shown in Figure 6, the power storage module 20X of the comparative embodiment does not include a second stack 22 and is formed by arranging a plurality of first unit cells 211 in the first direction. In such a case, in the plurality of first unit cells 211, the side surfaces of the first unit cells 211 each having the largest area are continuously arranged adjacent to each other in the first direction.Therefore, when a specific first unit cell 211 generates heat (when heat is generated at a position indicated by "F" in the figure), the heat is sequentially transferred from the first unit cell 211 located on the side closer to the first unit cell 211 that generated the heat to the first unit cell 211 located on the side farther from the first unit cell 211 that generated the heat through the side surfaces each having the largest area, as shown by an arrow AR2. As a result, the heat is more likely to be transferred to the entire power storage module 20X in the comparative embodiment than in the first embodiment. (Second version)

[0052] Fig. 7 is a schematic view of a power storage module and a cooler in a power storage device according to a second embodiment, when viewed from a side in the second direction. Fig. Fig. 8 is a schematic plan view of the power storage module and the cooler in the power storage device according to the second embodiment, when viewed from above. A power storage device 10A according to the second embodiment will be described with reference to Fig. Fig. 7 and Fig. 8 described.

[0053] As in the Fig. 7 and Fig. As shown in Fig. 8, the power storage device 10A of the second embodiment differs from the power storage device 10 of the first embodiment with respect to the configuration of a cooler 50A. The power storage device 10A of the second embodiment is otherwise substantially the same as the power storage device 10 of the first embodiment.

[0054] Each of the first stacks 21 comprises a plurality of side surfaces 21a, 21b, 21c, and 21d arranged around an axis orthogonal to the first direction (DR1) and the height direction. The axis orthogonal to the first direction and the height direction is parallel to the second direction. The side surfaces 21a and 21b face each other in the height direction, and the side surfaces 21c and 21d face each other in the first direction.

[0055] Each of the second stacks 22 includes a plurality of side surfaces 22a, 22b, 22c, and 22d arranged around the axis orthogonal to the first direction and the height direction. The side surfaces 22a and 22b face each other in the height direction, and the side surfaces 22c and 22d face each other in the first direction.

[0056] The cooler 50A is arranged in a meandering shape to cool two side surfaces of the plurality of side surfaces 21a, 21b, 21c, and 21d of the first stack 21 and two side surfaces of the plurality of side surfaces 22a, 22b, 22c, and 22d of the second stack 22. The above-described two side surfaces are mutually orthogonal side surfaces. The above-described side surfaces 21c and 21d are configured by side surfaces each having the largest area of ​​the side surfaces of the first unit cell 211. The above-described side surfaces 22a and 22b are configured by side surfaces each having the largest area of ​​the side surfaces of the second unit cell 212.

[0057] The radiator 50A has a plurality of first cooling sections 51, a plurality of second cooling sections 52, and a plurality of third cooling sections 53. The first cooling sections 51, the second cooling sections 52, and the third cooling sections 53 are provided so as to extend in the second direction. A coolant flow path through which coolant can flow is provided in each of the first cooling sections 51, the second cooling sections 52, and the third cooling sections 53, and the coolant flows through each of the cooling sections as indicated by an arrow in Fig. 8 shown.

[0058] The plurality of first cooling sections 51 are spaced apart from each other in the first direction. The first stack 21 and the second stack 22 are arranged between two first cooling sections 51 that are adjacent to each other in the first direction. The first cooling section 51 is arranged in every other gap of the gaps between the first stacks 21 and the second stacks 22 that are arranged in the first direction. The first cooling section 51 cools the side surface 21c of the first stack 21 and the side surface 22d of the second stack 22.

[0059] The plurality of second cooling sections 52 are arranged above the first stacks 21 and the second stacks 22. The plurality of third cooling sections 53 are arranged below the first stacks 21 and the second stacks 22. The plurality of second cooling sections 52 and the plurality of third cooling sections 53 are arranged such that two second cooling sections 52 and two third cooling sections 53 are alternately aligned on the upper and lower sides along the first direction.

[0060] Since the cooler 50A is provided in a meandering shape as described above, the first stacks 21 and the second stacks 22 can be cooled substantially uniformly. This can suppress the occurrence of heat dispersion in the first stacks 21 and the second stacks 22.

[0061] Although the example in which the cooler 50A is provided in a meandering shape to cool two side surfaces of each first stack 21 and two side surfaces of each second stack 22 was illustrated above, the present invention is not limited thereto. The cooler may be provided so as to extend in the first direction while passing through any gaps between the first stacks 21 and the second stacks 22 and meander in the height direction. Thereby, an upward- or downward-facing surface of the second unit cells 212 included in each second stack 22 in the stacked state can be cooled in the height direction by the cooler. In addition, a surface facing either side or the other in the first direction of first unit cells 211 can also be cooled by the cooler.

[0062] For example, the first cooling section 51 may be disposed in each gap between the first stack 21 and the second stack 22, which are adjacent to each other, and the cooler may be provided in a meandering shape to cool three side surfaces of the plurality of side surfaces 21a, 21b, 21c, and 21d of the first stack 21 and three side surfaces of the plurality of side surfaces 22a, 22b, 22c, and 22d of the second stack 22. Also in this case, the first stacks 21 and the second stacks 22 can be cooled substantially uniformly. (Further modifications)

[0063] Although the example in which the first direction in which the first stacks 21 and the second stacks 22 are alternately arranged is parallel to the width direction of the vehicle 1 has been illustrated and described above in the first and second embodiments, the present invention is not limited thereto. The above-described first direction may be parallel to the left-right direction of the vehicle 1 in the above-described assembled state. In this case, the above-described second direction is parallel to the front-rear direction of the vehicle in the above-described assembled state.

[0064] Although the embodiments of the present invention have been described, it should be understood that the embodiments disclosed herein are in all respects illustrative and not restrictive. The scope of the present invention is defined by the claims and is intended to include any modifications within the scope and meaning of the claims. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2024-009922

[0001] WO 2020 / 134 054A1 [0003, 0004]

Claims

[1] A power storage module (20) comprising a first stack (21) and a second stack (22) arranged alternately side by side in a first direction, wherein the first stack (21) comprises a plurality of first unit cells (211) arranged in the first direction, and the second stack (22) comprises a plurality of second unit cells (212) arranged in a height direction orthogonal to the first direction. [2] The power storage module (20) according to claim 1, wherein in the first stack (21) and the second stack (22) arranged alternately in the first direction, the first stack (21) is arranged at each of the two ends in the first direction. [3] Power storage device (10, 10A), comprising: the power storage module (20) according to claim 1 or 2; and a cooler (50, 50A) which cools the first stack (21) and the second stack (22). [4] The power storage device (10A) according to claim 3, wherein the cooler (50A) is provided to extend in the first direction while passing through a gap between the first stack (21) and the second stack (22) and meandering in the height direction. [5] Power storage device (10A) according to claim 4, wherein both the first stack (21) and the second stack (22) have a plurality of side surfaces arranged about an axis orthogonal to the first direction and the height direction, and the cooler (50A) is provided in a meandering shape to cool two side surfaces of the plurality of side surfaces of the first stack (21) and two side surfaces of the plurality of side surfaces of the second stack (22).

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