Power storage module, and power storage device

Abstract

To provide a power storage module that, when a predetermined unit cell generates heat, can prevent transmission of heat to the entire power storage module.SOLUTION: A power storage module 20 comprises a first stack 21 and a second stack 22 alternately arranged side by side in a first direction. The first stack 21 includes a plurality of first unit cells 211 arranged in the first direction, and the second stack 22 includes a plurality of second unit cells 212 arranged in a vertical direction orthogonal to the first direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a power storage module and a power storage device including the power storage module. [Background technology]

[0002] As a conventional energy storage module, International Publication No. 2020 / 134054 (Patent Document 1) discloses a configuration in which a plurality of unit cells are arranged side by side in a predetermined direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 134054 Summary of the Invention [Problem to be solved by the invention]

[0004] In a configuration in which a plurality of unit cells are arranged in one direction as in Patent Document 1, the side surfaces of the unit cells having the largest areas are arranged in the first direction. When a certain unit cell generates heat, the side surface expands in the first direction, and heat is transferred to the unit cells sequentially from the side closest to the first unit cell 211 that generated the heat to the side farther away. This raises concerns that heat may be transferred to the plurality of unit cells over a wide area in the first direction.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and an object of the present disclosure is to provide an energy storage module that can suppress heat transfer to the entire energy storage module when a specific unit cell generates heat, and an energy storage device that includes such an energy storage module. [Means for solving the problem]

[0006] An energy storage module according to the present disclosure includes a first stack and a second stack arranged alternately in a first direction. The first stack includes a plurality of first unit cells arranged in the first direction. The second stack includes a plurality of second unit cells arranged in a vertical direction perpendicular to the first direction.

[0007] Generally, when a unit cell generates heat, the center (belly) of the unit cell expands, and the heat is transferred to the adjacent unit cell.

[0008] According to the above configuration, by alternately arranging the first stacks and the second stacks having different stacking directions, the antinodes of the first unit cells included in the first stacks and the antinodes of the second unit cells included in the second stacks can be oriented in a different direction, thereby suppressing heat transfer between the first stacks and the second stacks.

[0009] In the energy storage module based on the present disclosure, the first stack and the second stack may be arranged alternately in the first direction, with the first stack being arranged at both ends in the first direction.

[0010] According to the above configuration, the first stack in which the antinodes of the first unit cells are aligned in the first direction is disposed at both ends in the first direction, which makes it easier to release heat outward in the first direction.

[0011] An electricity storage device according to the present disclosure includes the electricity storage module, and a cooler that cools the first stack and the second stack.

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

[0013] In the energy storage device according to the present disclosure, the cooler may be arranged to extend in the first direction while meandering in the vertical direction and passing through any one of the gaps between the first stack and the second stack.

[0014] According to the above configuration, the cooler is provided to extend in the first direction while meandering vertically, so that the cooler can cool the surfaces of the second unit cells included in the second stack stacked vertically, facing upward or downward, and the surfaces of the first unit cells facing either of the first directions, can also be cooled by the cooler.

[0015] In the power storage device according to the present disclosure, each of the first stack and the second stack may include a plurality of side surfaces arranged around an axis perpendicular to the first direction and the up-down direction. In this case, the cooler may be provided in a serpentine shape so as to cool two of the plurality of side surfaces of the first stack and two of the plurality of side surfaces of the second stack.

[0016] According to the above configuration, the cooler is provided in a serpentine shape, which allows the first stack and the second stack to be cooled substantially uniformly, thereby preventing uneven heat distribution within the first stack and the second stack. [Effects of the Invention]

[0017] According to the present disclosure, it is possible to provide an electricity storage module that can suppress heat transfer to the entire electricity storage module when a specific unit cell generates heat, and an electricity storage device including the electricity storage module. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic diagram of a vehicle equipped with an electricity storage device according to a first embodiment. [Figure 2] 1 is a diagram showing a state in which the power storage device according to the first embodiment is fixed to a vehicle. [Figure 3] 1 is a schematic exploded perspective view of an electricity storage device according to a first embodiment. [Figure 4] 1 is a schematic perspective view showing an electricity storage module and a cooler in an electricity storage device according to a first embodiment. FIG. [Figure 5]4 is a schematic diagram showing heat transfer when a predetermined unit cell generates heat in the electricity storage module according to the first embodiment. FIG. [Figure 6] FIG. 10 is a schematic diagram showing heat transfer when a predetermined unit cell generates heat in an electricity storage module according to a comparative example. [Figure 7] 10 is a schematic view of an electricity storage module and a cooler in an electricity storage device according to a second embodiment, viewed from one side in a second direction. FIG. [Figure 8] 10 is a schematic plan view of an electricity storage module and a cooler as viewed from above in an electricity storage device according to a second embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the embodiments described below, the same or common parts are denoted by the same reference numerals in the drawings, and the description thereof will not be repeated.

[0020] (Embodiment 1) Fig. 1 is a schematic diagram of a vehicle equipped with a power storage device according to embodiment 1. Fig. 2 is a diagram showing a state in which the power storage device according to embodiment 1 is fixed to a vehicle. Vehicle 1 according to embodiment 1 will be described with reference to Figs. 1 and 2.

[0021] The vehicle 1 is a hybrid vehicle that can run using at least one of the power of a motor and an engine, or an electric vehicle that runs using driving force obtained from electrical energy.

[0022] The vehicle 1 includes a vehicle body 2, front wheels 3, rear wheels 4, and an electricity storage device 10. The vehicle body 2 includes a frame member 5. The electricity storage device 10 has an upper surface 10a. The upper surface 10a also functions as a floor member that defines the interior of the vehicle cabin.

[0023] The framework member 5 includes a pair of side members 6 and a pair of side sills 7. The pair of side sills 7 are arranged on both ends of the vehicle 1 in the width direction. The pair of side members 6 are arranged at a distance inside the pair of side sills 7. The pair of side members 6 and the pair of side sills 7 extend along the front-rear direction of the vehicle 1.

[0024] The pair of side members 6 are spaced apart in the width direction of the vehicle 1. A main body 35 of the electricity storage device 10 is disposed in the gap between the pair of side members 6. A gap is provided between the main body 35 and the pair of side members 6. This makes it possible to suppress input of an impact to the electricity storage device 10 even in the event of a side collision of the vehicle 1.

[0025] Fixed portions 36 are provided on both side surfaces of the main body portion 35 in the width direction of the vehicle 1. The fixed portions 36 are fixed to the pair of side members 6 by fastening members 8.

[0026] The framework member 5 also includes a cross member 9. The cross member 9 is provided above the electricity storage device 10 so as to straddle from one side sill 7 to the other side sill 7. To the cross member 9, an upper surface 10a of the electricity storage device 10 is fixed.

[0027] In the above description, the framework member 5 includes a pair of side members 6 and a pair of side sills 7, but is not limited to this. The pair of side sills 7 may also function as the pair of side members 6. In this case, the pair of side members 6 can be omitted, and the above-mentioned fixed portion 36 may be fixed to the pair of side sills 7.

[0028] 3 is a schematic exploded perspective view of the power storage device according to Embodiment 1. The detailed configuration of the power storage device 10 will be described with reference to FIG.

[0029] The power storage device 10 includes a plurality of power storage modules 20, a housing case 30, a partition member 40, and a cooler 50 (see FIG. 4).

[0030] The multiple energy storage modules 20 are arranged side by side in a first direction (DR1 direction) and a second direction (DR2 direction) that is perpendicular to the up-down direction. The up-down direction is perpendicular to the first direction. The first direction is, for example, parallel to the left-right direction of the vehicle 1 when the energy storage device 10 is mounted on the vehicle 1. The second direction is parallel to the front-rear direction of the vehicle 1 when the energy storage device 10 is mounted on the vehicle 1. The up-down direction is parallel to the vertical direction, and is parallel to the up-down direction of the vehicle 1.

[0031] The energy storage module 20 includes a plurality of unit cells. A bus bar module is provided on each of one side and the other side of the energy storage module 20 in the first direction, and the plurality of unit cells are connected in series by the bus bar modules. The plurality of energy storage modules 20 are also connected in series.

[0032] The storage case 30 includes an upper member 31 and a lower member 32. The lower member 32 has a generally box-like shape that opens upward. The lower member 32 includes a main body portion 35 and a fixed portion 36. The main body portion 35 has a bottom wall portion 321, a first wall portion 322, a second wall portion 323, and side walls 324 and 325. The first wall portion 322, the second wall portion 323, and the side walls 324 and 325 are provided to stand up from the periphery of the bottom wall portion 321.

[0033] The first wall 322 and the second wall 323 face each other in the second direction. The side walls 324 and 325 face each other in the first direction. The fixed portions 36 are provided on the outer surfaces of the side walls 324 and 325.

[0034] The partition members 40 are provided to divide the storage space within the storage case 30. Specifically, the partition members 40 are provided to extend in a first direction and divide the storage space of the storage case 30 in a second direction. The partition members 40 define areas in which the power storage modules 20 are arranged. A power storage module 20 is arranged in each of the areas defined by the partition members 40.

[0035] The upper member 31 has a generally flat plate shape. The upper member 31 covers the plurality of energy storage modules 20 and closes the open space of the lower member 32. A sealing member may be filled in the gap between the upper member 31 and the energy storage modules 20. The sealing member may have insulating properties.

[0036] FIG. 4 is a schematic perspective view showing the electricity storage module and the cooler in the electricity storage device according to the first embodiment.

[0037] 4, the energy storage module 20 includes a plurality of first stacks 21 and a plurality of second stacks 22. The number of first stacks 21 and second stacks 22 can be set appropriately depending on the size of the vehicle 1. Note that the number of first stacks 21 and second stacks 22 is not limited to a plurality, and may be a single number.

[0038] The plurality of first stacks 21 and the plurality of second stacks 22 are arranged alternately in a first direction. The first stack 21 includes a plurality of first unit cells 211 arranged in the first direction. The second stack 22 includes a plurality of second unit cells 212 arranged in the vertical direction.

[0039] The first unit cell 211 and the second unit cell 212 have a longitudinal shape with the second direction as the longitudinal direction. The first unit cell 211 has a flattened rectangular parallelepiped shape with a thickness in the first direction. The second unit cell 212 has a flattened rectangular parallelepiped shape with a thickness in the vertical direction.

[0040] The first unit cell 211 and the second unit cell 212 may be configured from the same unit cell. In this case, the number of parts can be reduced, leading to lower manufacturing costs. Note that "same" includes manufacturing errors such as tolerances. Alternatively, the first unit cell 211 and the second unit cell 212 may be configured from different unit cells.

[0041] The first unit cell 211 and the second unit cell 212 are, for example, secondary batteries such as nickel-metal hydride batteries or lithium-ion batteries. The first unit cell 211 and the second unit cell 212 may use a liquid electrolyte or a solid electrolyte. The first unit cell 211 and the second unit cell 212 may be chargeable and dischargeable capacitors.

[0042] The first unit cell 211 and the second unit cell 212 each have a first end face and a second end face on one side and the other side in the second direction. The first end faces of the first unit cell 211 and the second unit cell 212 face the side wall 324. The second end faces of the first unit cell 211 and the second unit cell 212 face the side wall 325.

[0043] The first stack 21 is disposed at both ends of the energy storage module 20 in the first direction. That is, the first stack 21 and the second stack 22 are disposed alternately in the first direction, and the first stack 21 is disposed at both ends in the first direction. In such a case, the center portion (antinode) of the side surface having the largest area of the first unit cell 211 (described later) is exposed in the gap between the side wall portions 324, 325, and therefore heat can be easily released outward in the first direction. This can improve the heat dissipation performance of the energy storage module 20.

[0044] The cooler 50 is disposed, for example, below the power storage module 20. The cooler 50 is provided so as to be able to cool the power storage module 20. Specifically, for example, a refrigerant flow path is provided inside the cooler 50, through which a refrigerant flows for cooling the power storage module 20. The cooler 50 has a shape that expands in a planar direction perpendicular to the up-down direction. The cooler 50 may also be disposed above the power storage module 20.

[0045] 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 heat-conducting member with high thermal conductivity. The heat-conducting member may be an adhesive containing a silicone resin, an acrylic resin, a urethane resin, an epoxy resin, or the like.

[0046] FIG. 5 is a schematic diagram showing heat transfer when a predetermined unit cell generates heat in the electricity storage module according to the first embodiment.

[0047] 5, in the first stack 21, the side surfaces of the first unit cells 211 having the largest areas are aligned in the first direction. On the other hand, in the second stack 22, the side surfaces of the second unit cells 212 having the largest areas are aligned in the vertical direction.

[0048] When a unit cell generates heat, the center (belly) of the side surface with the largest area expands in the thickness direction (the first direction in the first unit cell 211, and the vertical direction in the second unit cell 212), thereby transferring the heat to the adjacent unit cell.

[0049] In this embodiment, by alternately arranging the first stack 21 and the second stack 22 having different stacking directions, the antinode direction of the first unit cell 211 included in the first stack 21 can be made different from the antinode direction of the second unit cell 212 included in the second stack 22.

[0050] Therefore, when a first unit cell 211 in a given first stack 21 generates heat (when heat is generated at the position indicated by F in the figure), the heat is transferred in the first stack 21 as indicated by arrow AR1. However, the antinodes of the first unit cells 211 arranged at both ends in the first direction are not close to the antinodes of the second unit cells 212 in the second stack 22, but are close to the side surfaces of the second unit cells 212 with smaller areas. This suppresses heat transfer from the first stack 21 to the second stack 22. Furthermore, because the antinodes of the second stack 22 face in the vertical direction, heat is less likely to be transferred from the second stack 22 to the first unit cells 211 located on the opposite side of the first stack 21 from the first stack 21 including the heated first unit cell 211. In this way, heat transfer between the first stack 21 and the second stack 22 can be suppressed, thereby suppressing heat transfer to the entire energy storage module 20.

[0051] (Comparative form) 6 is a schematic diagram showing heat transfer when a predetermined unit cell generates heat in a power storage module according to a comparative embodiment. Heat transfer in a power storage module 20X according to the comparative embodiment will be described with reference to FIG. 6.

[0052] As shown in FIG. 6, the energy storage module 20X according to the comparative embodiment does not include a second stack 22 and is configured by arranging a plurality of first unit cells 211 in a first direction. In such a case, the side surfaces of the plurality of first unit cells 211 having the largest areas are arranged consecutively in the first direction. Therefore, when a given first unit cell 211 generates heat (when heat is generated at the position indicated by F in the figure), the heat is transferred via the side surface having the largest area in order from the side closest to the first unit cell 211 that generated the heat to the first unit cell 211 located farthest from the first unit cell 211, as indicated by arrows AR2. As a result, heat is transferred more easily throughout the energy storage module 20 in the comparative embodiment than in the first embodiment.

[0053] (Embodiment 2) Fig. 7 is a schematic view of the power storage module and the cooler as viewed from one side in the second direction in the power storage device according to embodiment 2. Fig. 8 is a schematic plan view of the power storage module and the cooler as viewed from above in the power storage device according to embodiment 2. A power storage device 10A according to embodiment 2 will be described with reference to Figs. 7 and 8.

[0054] 7 and 8, the power storage device 10A according to the second embodiment differs from the power storage device 10 according to the first embodiment in the configuration of a cooler 50A. The other configurations are substantially the same.

[0055] The first laminate 21 includes a plurality of side surfaces 21a, 21b, 21c, and 21d arranged around an axis perpendicular to the first direction (DR1 direction) and the vertical direction. The axis perpendicular to the first direction and the vertical direction is parallel to the second direction. The side surfaces 21a and 21b face each other in the vertical direction, and the side surfaces 21c and 21d face each other in the first direction.

[0056] The second stack 22 includes a plurality of side surfaces 22a, 22b, 22c, and 22d arranged around an axis perpendicular to the first direction and the vertical direction. The side surfaces 22a and 22b face each other in the vertical direction, and the side surfaces 22c and 22d face each other in the first direction.

[0057] The cooler 50A is provided in a serpentine shape so as to cool two of the side surfaces 21a, 21b, 21c, and 21d of the first stack 21 and two of the side surfaces 22a, 22b, 22c, and 22d of the second stack 22. The two side surfaces are perpendicular to each other. The side surfaces 21c and 21d are the side surfaces of the first unit cell 211 that have the largest area. The side surfaces 22a and 22b are the side surfaces of the second unit cell 212 that have the largest area.

[0058] Cooler 50 has a plurality of first cooling sections 51, a plurality of second cooling sections 52, and a plurality of third cooling sections 53. First cooling sections 51, second cooling sections 52, and third cooling sections 53 are provided to extend in a second direction. First cooling section 51, second cooling section 52, and third cooling section 53 are provided with refrigerant flow paths through which refrigerant can flow, and the refrigerant flows through each cooling section as shown by the arrows in FIG. 8.

[0059] The multiple first cooling sections 51 are arranged at intervals in the first direction. A first stack 21 and a second stack 22 are arranged between two adjacent first cooling sections 51 in the first direction. A first cooling section 51 is arranged in every other gap between the multiple first stacks 21 and second stacks 22 lined up in the first direction. The first cooling sections 51 cool the side surface 21c of the first stack 21 and the side surface 21d of the second stack 22.

[0060] The multiple second cooling sections 52 are arranged above the first stack 21 and the second stack 22. The multiple third cooling sections 53 are arranged below the first stack 21 and the second stack 22. The multiple second cooling sections 52 and the multiple third cooling sections 53 are arranged such that two second cooling sections 52 and two third cooling sections 53 are alternately arranged vertically along the first direction.

[0061] In this way, by providing the cooler 50A in a serpentine shape, it is possible to substantially uniformly cool the first stack 21 and the second stack 22. This makes it possible to prevent uneven heat distribution from occurring within the first stack 21 and the second stack 22.

[0062] In the above description, the cooler 50A is provided in a serpentine shape to cool two side surfaces of the first stack 21 and two side surfaces of the second stack 22, but this is not limiting. The cooler may be provided so as to extend in the first direction while serpentine in the vertical direction and passing through any of the gaps between the first stack 21 and the second stack 22. This allows the cooler to cool the surfaces of the second unit cells 212 included in the second stack 22 stacked in the vertical direction, facing upward or downward. In addition, the cooler can also cool the surfaces of the first unit cells 211 facing either of the first directions.

[0063] For example, a first cooling section 51 may be disposed in each gap between adjacent first stack 21 and second stack 22, and the cooler may be provided in a serpentine shape so as to cool three of the multiple side surfaces 21a, 21b, 21c, and 21d of first stack 21 and three of the multiple side surfaces 22a, 22b, 22c, and 22d of second stack 22. Even in this case, first stack 21 and second stack 22 can be cooled substantially uniformly.

[0064] (Other variations) In the first and second embodiments described above, the first direction in which the first stack 21 and the second stack 22 are alternately arranged is parallel to the width direction of the vehicle 1, but this is not limiting. The first direction may be parallel to the left-right direction of the vehicle 1 in the mounted state. In this case, the second direction is parallel to the front-rear direction of the vehicle in the mounted direction.

[0065] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0066] REFERENCE SIGNS LIST 1 vehicle, 2 vehicle body, 3 front wheel, 4 rear wheel, 5 frame member, 6 side member, 7 side sill, 8 fastening member, 9 cross member, 10, 10A energy storage device, 10a upper surface, 20, 20X energy storage module, 21 first stack, 21a, 21b, 21c, 21d side surface, 22 second stack, 22a, 22b, 22c, 22d side surface, 30 storage case, 31 upper member, 32 lower member, 35 main body portion, 36 fixed portion, 40 partition member, 50, 50A cooler, 51 first cooling portion, 52 second cooling portion, 53 third cooling portion, 211 first unit cell, 212 second unit cell, 321 bottom wall portion, 322 first wall portion, 323 second wall portion, 324, 325 side wall portion.

Claims

1. The laminated structure includes first and second stacks arranged alternately in a first direction, the first stack includes a plurality of first unit cells arranged in the first direction, the second stack includes a plurality of second unit cells arranged in a vertical direction perpendicular to the first direction.

2. The energy storage module according to claim 1 , wherein the first stacked bodies and the second stacked bodies are alternately arranged in the first direction, and the first stacked bodies are arranged at both ends in the first direction.

3. The energy storage module according to claim 1 or 2; a cooler that cools the first stack and the second stack.

4. 4. The power storage device according to claim 3, wherein the cooler is provided so as to extend in the first direction while meandering in the up-down direction and passing through any one of the gaps between the first stack and the second stack.

5. each of the first stacked body and the second stacked body includes a plurality of side surfaces arranged around an axis perpendicular to the first direction and the up-down direction; 5. The energy storage device according to claim 4, wherein the cooler is arranged in a serpentine manner so as to cool two of the plurality of side surfaces of the first stack and two of the plurality of side surfaces of the second stack.

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