Power storage device

Abstract

To provide a power storage device that can increase the filling properties of a heat conduction layer arranged between a lower case and a cooler arranged outside the lower case.SOLUTION: A power storage device comprises: a lower case that has a bottom part 23; a cooler 30 that is arranged below the bottom part 23 and has a top face 30a facing the bottom face 23; and a heat conduction layer that is provided between the bottom part 23 and the top face 30a. The top face 30a includes a pair of raised parts 34 that are provided at an interval therebetween and raised toward the bottom part 23, and a projection 35 that is arranged between the pair of raised parts 34 and projects toward the bottom part 23.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to an electricity storage device mounted on a vehicle. [Background technology]

[0002] As a conventional electricity storage device, JP 2020-053148 A (Patent Document 1) discloses a structure in which a power storage stack and a cooler are arranged in a storage case, and a thermally conductive material is provided between the power storage stack and the cooler. The thermally conductive material is made of gel-like grease. Even if the external dimensions (more specifically, the height dimensions) of the multiple power storage cells included in the power storage stack vary, the gel-like grease deforms to follow the variation, thereby improving the adhesion between the cooler and the power storage stack. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-053148 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the cooler is disposed inside the housing case, but instead of such a configuration, a configuration in which the cooler is disposed outside the housing case is being considered. In such a case, it is considered to thermally adhere the bottom of the lower case and the top surface of the cooler to each other via a thermally conductive layer.

[0005] However, when a raised portion is formed on the upper surface of the cooler, the heat conductive layer does not easily spread at the end of the raised portion, and the thickness of the heat conductive layer becomes small. In such a case, a gap is formed between the cooler and the power storage stack, making it difficult to seal the gap between the cooler and the power storage stack. When the cooler is disposed outside the lower case, liquid such as water easily penetrates into the gap, and the cooler or the lower case is easily rusted by the liquid.

[0006] 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 device that can improve the filling property of a thermally conductive layer that is arranged between a cooler arranged outside the lower case and the lower case. [Means for solving the problem]

[0007] The present disclosure provides an energy storage device comprising a lower case having a bottom, a cooler disposed below the bottom and having an upper surface facing the bottom, and a thermally conductive layer disposed between the bottom and the upper surface, the upper surface including a pair of raised portions spaced apart from each other and raised toward the bottom, and a protrusion disposed between the pair of raised portions and protruding toward the bottom.

[0008] According to the above-mentioned configuration, by providing the protrusions between the pair of raised portions, when the thermally conductive layer is sandwiched between the bottom of the lower case and the upper surface of the cooler, the protrusions spread the thermally conductive layer toward the pair of raised portions, thereby allowing the thermally conductive layer to be filled between the ends of the pair of raised portions located on the protrusion side and the bottom of the lower case.

[0009] In the power storage device based on the present disclosure, the bottom portion may have a recess that recesses toward a space between the pair of raised portions.

[0010] According to the above configuration, the thermally conductive layer arranged between a pair of raised portions can be pushed out by the recess, thereby making it possible to more reliably fill the gap between the ends of the pair of raised portions located on the protrusion side and the bottom of the lower case with the thermally conductive layer.

[0011] In the power storage device according to the present disclosure, the upper surface has a first flat portion disposed between the pair of raised portions. Each of the pair of raised portions includes a second flat portion located closer to the bottom portion than the first flat portion, and a connection surface portion connecting the second flat portion and the first flat portion. In this case, it is preferable that the recess includes a bottom plate portion facing the first flat portion and parallel to the first flat portion, and a side wall portion facing the connection surface portion and parallel to the connection surface portion.

[0012] According to the above configuration, while maintaining the gap between the first plane portion and the bottom plate portion, and the gap between the connection surface portion and the side wall portion constant, a thermally conductive layer can be filled between the first plane portion and the bottom plate portion, and between the connection surface portion and the side wall portion.

[0013] In the power storage device according to the present disclosure, the protrusion has an upper end portion facing the bottom portion, and in this case, a width of the upper end portion in a direction perpendicular to a direction perpendicular to a direction in which the pair of raised portions are arranged is preferably shorter than a width of the thermal conduction layer in the direction perpendicular to the direction.

[0014] According to the above-mentioned configuration, the thermally conductive layer can be more reliably expanded toward the pair of raised portions.

[0015] The energy storage device according to the present disclosure includes an energy storage stack including a plurality of energy storage cells arranged in a first direction. The energy storage stack is disposed on the side opposite to the side on which the cooler is disposed with respect to the bottom, and is in thermal contact with the bottom. In this case, the cooler may include a cooling section extending in the first direction for cooling the energy storage stack, a pair of holding sections disposed at an interval in the first direction and holding the cooling section, and a connecting section connecting the pair of holding sections. Each of the pair of holding sections has a one-side end portion on one side in a second direction perpendicular to the first direction. In this case, the connecting section may connect the one-side end portions of each of the pair of holding sections, and the pair of raised portions and the protrusion may be provided on the connecting section.

[0016] According to the above configuration, a thermally conductive layer can be filled between the cooler (more specifically, the connection portion) and the bottom of the lower case on one side in the second direction, and liquid can be prevented from entering between the cooler and the bottom from the one side in the second direction. In particular, when the power storage device is mounted on a vehicle so that the one side in the second direction is the front side of the vehicle, liquid splashed up by the front wheels is likely to splash on the connection portion located on the one side in the second direction. Even in such a case, since a thermally conductive layer is filled between the connection portion and the bottom, it is possible to prevent the liquid from entering between the cooler and the bottom. As a result, corrosion of the bottom or the connection portion can be suppressed. Effect of the Invention

[0017] According to the present disclosure, it is possible to provide an electricity storage device capable of improving the filling property of a thermally conductive layer disposed between the lower case and a cooler disposed outside the lower case. [Brief description of the drawings]

[0018] [Figure 1] 1 is a diagram showing a vehicle equipped with a power storage device according to an embodiment; [Diagram 2] 1 is an exploded perspective view of an electricity storage device according to an embodiment; [Diagram 3] 2 is an exploded perspective view of a cooler and a lower case of the power storage device according to the embodiment, as viewed from the bottom side of the lower case. FIG. [Figure 4] 2 is an exploded perspective view of a lower case and a cooler in an electricity storage device according to an embodiment, showing an enlarged view of the vicinity of a pair of raised portions 34 of the cooler. FIG. [Diagram 5] 5A and 5B are diagrams illustrating a state of a thermally conductive layer before being sandwiched between a cooler and a lower case in the power storage device according to the embodiment. [Figure 6] 6 is a diagram showing a state in which the thermally conductive layer applied in FIG. 5 is sandwiched between the bottom of the lower case and the cooler. [Figure 7] 4 is a cross-sectional view showing a state in which a thermally conductive layer is sandwiched between a cooler and a lower case in the electricity storage device according to the embodiment; FIG. [Figure 8] 4 is a plan view showing a state in which a thermally conductive layer is sandwiched between a cooler and a lower case in the electricity storage device according to the embodiment; FIG. [Figure 9] 13 is a plan view showing a modified example in which a thermally conductive layer is sandwiched between a cooler and a lower case. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 characters in the drawings, and the description thereof will not be repeated.

[0020] Fig. 1 is a diagram showing a vehicle equipped with a power storage device according to an embodiment of the present invention. With reference to Fig. 1, a vehicle 100 according to the embodiment of the present invention will be described.

[0021] Vehicle 100 according to the embodiment includes a power storage device 1, and can run using electricity stored in the power storage device 1. Vehicle 100 also includes a floor panel 2, front wheels 3, and rear wheels 4. Power storage device 1 is mounted below floor panel 2. A front end of power storage device 1 is located on the front wheel 3 side. The front end of power storage device 1 may be disposed so as to overlap with front wheel 3 when viewed from the width direction of the vehicle.

[0022] Fig. 2 is an exploded perspective view of the electricity storage device according to the embodiment. With reference to Fig. 2, the electricity storage device 1 according to the embodiment will be described.

[0023] As shown in FIG. 2, the energy storage device 1 according to the embodiment includes a plurality of energy storage stacks 10, a storage case 20, a cooler 30, a thermally conductive layer 40, a share panel 50, and an inner thermally conductive layer 60.

[0024] Each of the plurality of power storage stacks 10 includes a plurality of power storage cells 11 arranged in a first direction (DR1 direction). When the power storage device 1 is mounted on the vehicle 100, the first direction is parallel to the width direction of the vehicle.

[0025] The storage cell 11 is, for example, a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. The storage cell 11 has, for example, a rectangular shape. The storage cell 11 may use a liquid electrolyte or a solid electrolyte. The storage cell 11 may also be a unit capacitor configured to be capable of storing electricity.

[0026] The power storage stacks 10 are arranged side by side in a second direction (DR2 direction) perpendicular to the vertical direction and the first direction. In the mounted state, the second direction is parallel to the front-rear direction of the vehicle.

[0027] The storage case 20 accommodates a plurality of power storage stacks 10. The storage case 20 includes an upper case 21 and a lower case 22.

[0028] The upper case 21 has a generally box-like shape that is open downward. The upper case 21 may be made of a metal material. Moreover, in order to reduce weight, the upper case 21 may be made of a resin material.

[0029] The lower case 22 has a generally box-like shape that is open upward. The lower case 22 is made of a metal material. The lower case 22 preferably has good thermal conductivity.

[0030] The lower case 22 has a bottom 23. The multiple power storage stacks 10 are placed on the bottom 23. The bottom 23 has an inner surface 23a and an outer surface 23b that face each other. The inner surface 23a faces the multiple power storage stacks 10. The outer surface 23b faces the side opposite to the side on which the multiple power storage stacks 10 are located.

[0031] The bottom portion 23 is provided with a plurality of protruding portions 25 that protrude downward. The plurality of protruding portions 25 are arranged in a line at intervals in the second direction. The plurality of protruding portions 25 enter, at predetermined positions, gaps between adjacent cooling portions 32 (described below). The plurality of protruding portions 25 extend along the first direction.

[0032] The inner thermally conductive layer 60 is disposed between each of the power storage stacks 10 and the inner surface 23a. The inner thermally conductive layer 60 also functions as an adhesive layer, and adhesively fixes each of the power storage stacks 10 to the bottom 23. Each of the power storage stacks 10 is in thermal contact with the inner surface 23a via the inner thermally conductive layer 60.

[0033] The inner thermally conductive layer 60 is made of a resin member having thermal conductivity. For the inner thermally conductive layer 60, for example, a silicone-based resin, an acrylic-based resin, or an adhesive containing an epoxy resin or the like can be used.

[0034] The cooler 30 is a device for cooling the multiple electricity storage stacks 10. A refrigerant flow path through which a refrigerant flows is provided inside the cooler 30. The refrigerant flow path is connected to a refrigerant inlet portion 61 and a refrigerant outlet portion 62. The refrigerant introduced from the refrigerant inlet portion 61 to the refrigerant flow path cools the multiple electricity storage stacks 10 and is discharged from the refrigerant outlet portion 62.

[0035] The cooler 30 is disposed below the bottom 23 of the lower case 22. The cooler 30 has an upper surface 30a facing the bottom 23. The cooler 30 is made of a metal material such as aluminum. A detailed structure of the cooler 30 will be described later with reference to FIG. 3.

[0036] The thermally conductive layer 40 is disposed between the outer surface 23b of the bottom 23 and the upper surface 30a of the cooler 30. The multiple electricity storage stacks 10 are cooled by the cooler 30 via the thermally conductive layer 40, the bottom 23, and the inner thermally conductive layer 60. The thermally conductive layer 40 also functions as an adhesive layer that bonds the bottom 23 and the cooler 30. As the thermally conductive layer 40, for example, an adhesive containing a silicone resin, an acrylic resin, an epoxy resin, or the like can be used.

[0037] The shear panel 50 is disposed so as to cover the above-mentioned multiple protrusions 25 and the cooler 30 from below. The shear panel 50 protects the cooler 30 and prevents the cooler 30 from being exposed to water. The shear panel 50 is made of a metal material.

[0038] Fig. 3 is an exploded perspective view of a cooler and a lower case of the power storage device according to the embodiment, as viewed from the bottom side of the lower case, in which the up-down direction is inverted.

[0039] 3, the cooler 30 includes a pair of holding parts 31, a plurality of cooling parts 32, and a connection part 33. Inside the pair of holding parts 31, the plurality of cooling parts 32, and the connection part 33, the above-mentioned refrigerant flow path is arranged.

[0040] The pair of holding parts 31 extend along the second direction. The pair of holding parts 31 have one side end parts 31a on one side in the second direction. The pair of holding parts 31 are disposed apart from each other in the first direction. The pair of holding parts 31 hold the multiple cooling parts 32.

[0041] The multiple cooling units 32 are arranged at positions corresponding one-to-one to the multiple power storage stacks 10. The multiple cooling units 32 are provided according to the number of the multiple power storage stacks 10. Each of the multiple cooling units 32 is provided so as to connect a pair of holding units 31 in the first direction. The multiple cooling units 32 are arranged side by side at intervals in the second direction.

[0042] The connection part 33 connects the pair of holding parts 31. Specifically, the connection part 33 connects one side end parts 31a of each of the pair of holding parts 31. The connection part 33 constitutes one end part of the cooler 30. The connection part 33 has a substantially C-shape. A gap is formed between the connection part 33 and the cooling part 32 located on one side in the second direction among the multiple cooling parts 32. The connection part 33 is provided with the above-mentioned refrigerant introduction part 61 and refrigerant discharge part 62.

[0043] The bottom portion 23 of the lower case 22 has an opposing portion 23c that faces the connecting portion 33. The opposing portion 23c is provided with a recess 24 that is recessed toward between a pair of raised portions 34 (see FIG. 4) described below.

[0044] FIG. 4 is an exploded perspective view of a lower case and a cooler, showing an enlarged view of the vicinity of a pair of raised portions 34 in the electricity storage device according to the embodiment.

[0045] The upper surface 30a of the cooler 30 has a pair of raised portions 34 and a protrusion 35. The pair of raised portions 34 are provided on the connecting portion 33. The pair of raised portions 34 are provided at an interval from each other in the first direction. The pair of raised portions 34 rise toward the bottom portion 23. The pair of raised portions 34 are hollow inside, and the hollow forms a refrigerant flow path through which the above-mentioned refrigerant flows.

[0046] The upper surface 30a of the cooler 30 has a first flat portion 331 disposed between a pair of raised portions 34. The first flat portion 331 is substantially parallel to the first direction and the second direction.

[0047] The pair of raised portions 34 has a second flat portion 341 and a connecting surface portion 342. The second flat portion 341 is located closer to the bottom portion 23 than the first flat portion 331. The height position of the second flat portion 341 is higher than that of the first flat portion 331. The second flat portion 341 is substantially parallel to the first direction and the second direction. The connecting surface portion 342 connects the second flat portion 341 and the first flat portion 331. Specifically, the connecting surface portion 342 connects the end of the second flat portion 341 located on the protrusion 35 side and the first flat portion 331. The connecting surface portion 342 faces the protrusion 35 side. The connecting surface portion 342 has a substantially tapered shape.

[0048] The protrusion 35 is provided on the connection portion 33. The protrusion 35 is provided between a pair of raised portions 34. The protrusion 35 protrudes toward the bottom portion 23. The protrusion 35 has an upper end portion 35a that faces the bottom portion 23 (more specifically, the bottom wall portion 241). The upper end portion 35a is formed flat.

[0049] The facing portion 23c includes a plate-shaped portion 26 and a recess 24. The plate-shaped portion 26 is provided so as to face the second flat surface portion 341. The plate-shaped portion 26 is substantially parallel to the second flat surface portion 341.

[0050] The recess 24 includes a bottom plate portion 241 and a pair of side wall portions 242. The bottom plate portion 241 faces the first flat portion 331. The bottom plate portion 241 is parallel to the first flat portion 331. The pair of side wall portions 242 connect the bottom plate portion 241 and the plate-shaped portion 26. More specifically, the side wall portion located on one side of the pair of side wall portions 242 in the first direction connects one end of the bottom plate portion 241 in the first direction to the plate-shaped portion 26. The side wall portion located on the other side of the pair of side wall portions 242 in the first direction connects the other end of the bottom plate portion 241 in the first direction to the plate-shaped portion 26. The pair of side wall portions 242 face the connection surface portions 342 of the pair of raised portions 34. The pair of side wall portions 242 are parallel to the connection surface portions 342 of the pair of raised portions 34.

[0051] FIG. 5 is a diagram showing a state of a thermally conductive layer before being sandwiched between a cooler and a lower case in an electricity storage device according to an embodiment.

[0052] As shown in FIG. 5, the thermally conductive layer 40 before being sandwiched between the cooler 30 and the lower case 22 is applied along the first direction in the connection portion 33 so as to overlap the second flat portion 341, the first flat portion 331, and the upper end portion 35a of the protrusion 35. The thermally conductive layer 40 may be applied to the upper surface 30a of the cooler 30, or may be applied to the outer surface 23b of the bottom portion 23 in a portion corresponding to the upper surface 30a. Before being sandwiched, the width of the thermally conductive layer 40 in the second direction may be smaller than the width of the pair of raised portions 34 and the width of the protrusion 35 in the second direction. More specifically, before being sandwiched, the width of the thermally conductive layer 40 may be smaller than the width of the upper end portion 35a of the protrusion 35.

[0053] FIG. 6 is a diagram showing how the thermally conductive layer applied in FIG. 5 is sandwiched between the bottom of the lower case and the cooler.

[0054] 6, the lower case 22 and the cooler 30 are arranged so that the plate-like portion 26, the side wall portion 242, and the bottom plate portion 241 face the second flat portion 341, the connection surface portion 342, and the first flat portion 331, respectively, and the lower case 22 is moved relatively so that the lower case 22 and the cooler 30 approach each other. As a result, the thermally conductive layer 40 is sandwiched between the bottom portion 23 and the upper surface 30a of the cooler 30.

[0055] 7 and 8 are a cross-sectional view and a plan view showing a state in which a thermally conductive layer is sandwiched between a cooler and a lower case in an electricity storage device according to an embodiment. For convenience, the lower case is omitted in FIG. 8. By sandwiching the cooler 30 and the lower case 22, a thermally conductive layer 40 is formed between the bottom 23 and the upper surface 30a of the cooler 30.

[0056] 7, when the thermally conductive layer 40 is sandwiched between the bottom 23 of the lower case 22 and the upper surface 30a of the cooler 30, the protrusions 35 are provided between the pair of raised portions 34, so that the thermally conductive layer 40 is pushed and spread by the protrusions 35 toward the connecting surface 342 of the pair of raised portions 34, as indicated by the arrows in the figure. This allows the thermally conductive layer 40 to fill the gap between the ends of the pair of raised portions 34 located on the protrusion 35 side and the bottom 23 of the lower case 22.

[0057] At this time, since the bottom 23 is provided with the recess 24 recessed toward between the pair of raised portions 34, the thermally conductive layer 40 disposed between the pair of raised portions 34 can be further expanded by the recess 24. This makes it possible to more reliably fill the gap between the ends of the pair of raised portions 34 located on the protrusion 35 side and the bottom 23 of the lower case 22 with the thermally conductive layer 40.

[0058] In addition, the bottom plate portion 241 of the recess 24 faces the first flat portion 331 so as to be parallel to the first flat portion 331, and the side wall portion 242 of the recess faces the connection surface portion 342 so as to be parallel to the connection surface portion 342, so that the thermally conductive layer 40 can be filled between the first flat portion 331 and the bottom plate portion 241 and between the connection surface portion 342 and the side wall portion 242 while keeping the distance between the first flat portion 331 and the bottom plate portion 241 and the distance between the connection surface portion 342 and the side wall portion 242 constant. In other words, the thickness of the thermally conductive layer 40 can be made constant.

[0059] 8, in the state where the thermally conductive layer 40 is sandwiched, the width W1 of the upper end 30a in the orthogonal direction (second direction) perpendicular to the direction (first direction) in which the pair of raised portions 34 are arranged is shorter than the width W2 of the thermally conductive layer in the orthogonal direction. By forming the protrusions 35 to have such a length relationship, the thermally conductive layer 40 can be more reliably pushed and spread toward the pair of raised portions 34.

[0060] Furthermore, in a state where the thermally conductive layer 40 is sandwiched, the width W3 of the protrusion 35 in the perpendicular direction may be longer than the width W2 of the thermally conductive layer 40 in the perpendicular direction. When the width W3 and the width W2 have such a relationship, the amount of the thermally conductive layer 40 applied can be reduced while improving the filling property of the thermally conductive layer 40 between the cooler 30 and the bottom 23. As a result, the manufacturing cost can also be reduced.

[0061] FIG. 9 is a plan view showing a modified example in which a thermally conductive layer is sandwiched between a cooler and a lower case.

[0062] 9, in the state in which the thermally conductive layer 40 is sandwiched, the width W3 of the protrusions 35 may be smaller than the width W2 of the thermally conductive layer 40. In this case, by increasing the amount of the thermally conductive layer 40 applied, the thermally conductive layer 40 can be more reliably spread toward the pair of protrusions 34, and the filling property of the thermally conductive layer 40 between the cooler 30 and the bottom 23 can be more reliably improved.

[0063] As described above, the electricity storage device 1 is mounted on the vehicle 100 so that the connection portion 33 located on one side in the second direction is located on the front side of the vehicle. In this state, the connection portion 33 is disposed near the front wheels 3 of the vehicle, and is easily splashed with liquid splashed up by the front wheels. Even in such a case, since the heat conductive layer 40 is filled between the connection portion 33 and the bottom portion 23 as described above, it is possible to prevent the liquid from penetrating between the cooler 30 and the bottom portion 23. As a result, it is possible to prevent corrosion of the bottom portion 23 or the connection portion 33.

[0064] The embodiments disclosed herein are illustrative and not restrictive in all respects. 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]

[0065] 1 Energy storage device, 2 Floor panel, 3 Front wheel, 4 Rear wheel, 10 Energy storage stack, 11 Energy storage cell, 20 Storage case, 21 Upper case, 22 Lower case, 23 Bottom, 23a Inner surface, 23b Outer surface, 23c Opposing portion, 24 Recess, 25 Protruding portion, 26 Plate-shaped portion, 30 Cooler, 30a Upper surface, 31 Holding portion, 31a One side end portion, 32 Cooling portion, 33 Connection portion, 34 Raised portion, 35 Protruding portion, 35a Upper end portion, 40 Thermally conductive layer, 50 Share panel, 60 Inner thermally conductive layer, 61 Coolant introduction portion, 62 Coolant discharge portion, 100 Vehicle, 241 Bottom plate portion, 242 Side wall portion, 331 First flat portion, 341 Second flat portion, 342 Connection surface portion.

Claims

1. a lower case having a bottom; a cooler disposed below the bottom and having an upper surface facing the bottom; a thermally conductive layer disposed between the bottom and the top surface; the upper surface includes a pair of raised portions spaced apart from each other and raised toward the bottom portion, and a protrusion disposed between the pair of raised portions and protruding toward the bottom portion, The bottom portion has a recess that is recessed toward a space between the pair of raised portions, the upper surface has a first planar portion disposed between the pair of raised portions; Each of the pair of raised portions includes a second planar portion located closer to the bottom portion than the first planar portion, and a connection surface portion connecting the second planar portion and the first planar portion, the recess includes a bottom plate portion facing the first flat portion and parallel to the first flat portion, and a side wall portion facing the connection surface portion and parallel to the connection surface portion, the protrusion has an upper end portion facing the bottom plate portion and protrudes from the first flat portion toward the bottom plate portion, a distance from the upper end portion to the bottom plate portion is shorter than a distance from the first flat portion to the bottom plate portion, a width of the upper end in a direction perpendicular to a direction in which the pair of raised portions are arranged is shorter than a width of the thermal conduction layer in the direction perpendicular to the direction in which the pair of raised portions are arranged.

2. A storage stack including a plurality of storage cells arranged in a first direction, the power storage stack is disposed on an opposite side of the bottom from a side on which the cooler is disposed, and is in thermal contact with the bottom; the cooler includes a cooling portion extending in the first direction and configured to cool the power storage stack, a pair of holding portions arranged at an interval in the first direction and configured to hold the cooling portion, and a connection portion connecting the pair of holding portions, Each of the pair of holding portions has a first end portion on one side in a second direction perpendicular to the first direction, the connecting portion connects the one-side end portions of the pair of holding portions, The power storage device according to claim 1 , wherein the pair of raised portions and the protrusion are provided on the connection portion.

Images