Electric energy storage device

Abstract

To provide a power storage device with which it is possible to suppress the occurrence of short-circuiting even when an electrolyte has leaked from one of a plurality of laminated cells.SOLUTION: A power storage device 1 comprises a plurality of cells 10 that are arrayed in the vertical direction, and a plurality of spacers 20, each of which is disposed between the adjacent cells. Each of the plurality of cells 10 includes an outer packaging 16 that accommodates an electrolyte in the inside, and a first terminal 11 and a second terminal 12, the first terminal 11 and the second terminal 12 being alternately arranged in the vertical direction in each of a first protrusion direction and a second protrusion direction protruding from the outer packing when seen from above, each of the plurality of spacers 20 including a first edge 21 that protrudes outward of an edge of the outer packaging in the first protrusion direction and a second edge 22 that protrudes outward of an edge of the outer packaging in the second protrusion direction. An extension heading to one side in the vertical direction is provided to each of the first edge 21 and the second edge 22.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a power storage device.

Background Art

[0002] In recent years, various power storage devices have been developed for use as power sources for electric vehicles and hybrid vehicles.

[0003] Japanese Patent Application Laid-Open No. 2013-229266 (Patent Document 1) discloses a battery module as a power storage device. The battery module includes a plurality of flat batteries stacked in the vertical direction. As the battery, a rectangular laminate battery in which an electrode body formed by laminating a positive electrode, a negative electrode, and a separator is sealed with a laminate film is used.

[0004] In this laminate battery, electrode tabs (terminal portions) made of thin metal plates are led out in a strip shape from the laminate film as an exterior from the center of both end portions that are short sides. The plurality of batteries are stacked in alternating directions such that the electrode tabs on the positive electrode side and the electrode tabs on the negative electrode side alternate. By connecting the electrode tabs on the positive electrode side and the electrode tabs on the negative electrode side that are alternately adjacent to each other on one side and the other side in the long side direction, the plurality of batteries are connected in series as a whole.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the power storage device disclosed in Patent Document 1, when a part of the exterior is damaged, the electrolytic solution leaks from the inside of the exterior to the outside. In such a case, if there is no measure, the leaked electrolytic solution flows downward along the outer peripheral surface of the exteriors of a plurality of batteries laminated on each other. At this time, although arranged in the vertical direction, the positive electrode side electrode tab and the negative electrode side electrode tab that are not directly connected to each other may be electrically connected via the electrolytic solution. As a result, there is a risk of short circuit in the power storage device.

[0007] The present disclosure has been made in view of the above problems, and an object of the present disclosure is to provide a power storage device capable of suppressing the occurrence of a short circuit even when the electrolytic solution leaks from any of a plurality of stacked cells.

Means for Solving the Problems

[0008] The power storage device according to the present disclosure includes a plurality of cells arranged in the vertical direction, and a plurality of spacers alternately laminated with the plurality of cells in the vertical direction and each disposed between adjacent cells in the vertical direction. Each of the plurality of cells includes an exterior body that houses an electrolytic solution therein, and a first terminal portion and a second terminal portion that protrude from the exterior body. The first terminal portion and the second terminal portion protrude alternately in the vertical direction in each of a first protruding direction protruding from the exterior body when viewed from above and a second protruding direction different from the first protruding direction. Each of the plurality of spacers includes a first end portion protruding outward from an end portion of the exterior body in the first protruding direction, and a second end portion protruding outward from the end portion of the exterior body in the second protruding direction. An extending portion extending toward one side in the vertical direction is provided at each of the first end portion and the second end portion.

[0009] According to the above configuration, when the exterior body of the upper cell among adjacent cells is damaged and the electrolytic solution leaks out, the electrolytic solution reaches the upper surface of the spacer along the outer peripheral surface of the exterior body. The electrolytic solution that has reached the upper surface of the spacer heads towards the extending portion provided at the first end portion and / or the extending portion provided at the second end portion of the spacer. When the extending portion faces upward, the electrolytic solution can be retained inside the extending portion. When the extending portion faces downward, since the first end portion and the second end portion protrude outside the exterior body of the lower cell among adjacent cells, the electrolytic solution that has headed towards the extending portion drips downward from the extending portion without passing along the side surface of the exterior body of the lower cell. At this time, the flow path of the leaked electrolytic solution is cut off. In this way, it is possible to suppress the electrical connection between the first terminal portion and the second terminal portion of adjacent cells via the electrolytic solution at unintended locations. As a result, it is possible to suppress the occurrence of a short circuit in the power storage device.

[0010] In the power storage device based on the present disclosure, the extending portion may extend downward.

[0011] According to the above configuration, the electrolytic solution leaked from the exterior body of the cell located above the spacer can be dripped downward from the lower end of the extending portion without being transmitted to the side surface of the exterior body of the lower cell.

[0012] In the power storage device based on the present disclosure, the extending portion may extend upward.

[0013] According to the above configuration, the electrolytic solution leaked from the exterior body of the cell located above the spacer can be retained inside the extending portion.

[0014] In the power storage device based on the present disclosure, the spacer preferably has electrolytic solution resistance.

[0015] According to the above configuration, when the electrolytic solution leaks from the cell, it is possible to suppress the corrosion of the spacer by the electrolytic solution.

[0016] The power storage device based on the present disclosure may further include a housing case having a bottom and housing the plurality of cells and the plurality of spacers, and a bottom-side spacer disposed between the lowermost cell and the bottom. In this case, the bottom-side spacer may have a first protruding end portion that protrudes outward from the end portion of the exterior body in the first protruding direction, and a second protruding end portion that protrudes outward from the end portion of the exterior body in the second protruding direction. Further, an extending portion extending upward may be provided at each of the first protruding end portion and the second protruding end portion.

[0017] According to the above configuration, when the exterior body of the upper cell is damaged and the electrolytic solution that has fallen from the extending portion of the spacer toward the bottom is blocked by the extending portions provided at the first protruding end portion and the second protruding end portion of the bottom-side spacer. Also, the height positions of the first terminal portion and the second terminal portion of the lowermost cell can be increased by the thickness of the bottom-side spacer. Thereby, it is possible to suppress the lowermost cell from being affected by the electrolytic solution that has fallen to the bottom.

[0018] The power storage device based on the present disclosure may further include a plurality of connection portions that electrically connect the first terminal portions and the second terminal portions of the adjacent cells so that the plurality of cells are connected in series. In this case, the first protruding direction may be one side in the lateral direction orthogonal to the vertical direction, and the second protruding direction may be the other side in the lateral direction. Further, one of the first end portion and the second end portion of each of the plurality of spacers may face one of the plurality of connection portions in the lateral direction. Furthermore, the other end of each of the first end portion and the second end portion of each of the plurality of spacers may protrude outward in the lateral direction from the first terminal portion and the second terminal portion that are alternately arranged in the vertical direction when viewed from above.

[0019] According to the above configuration, on the side where the first terminal and the second terminal are not connected by the connecting portion in the vertical direction, the end of the spacer in the horizontal direction is located laterally outward of the first terminal and the second terminal arranged in the vertical direction. As a result, when electrolyte leaks from an upper cell among adjacent cells, the electrolyte can be guided outward of the first terminal and the second terminal arranged in the vertical direction on the side where the first terminal and the second terminal are not connected by the connecting portion in the vertical direction.

[0020] The power storage device according to the present disclosure may further include a case having a bottom and configured to accommodate the cells and the spacers, and in this case, the bottom may be provided with a retention portion for retaining the electrolyte leaked from at least any of the cells.

[0021] With this configuration, when the outer casing of the upper cell is damaged, the electrolyte that falls from the extension of the spacer toward the bottom can be retained in the retention section, thereby preventing the electrolyte that has fallen to the bottom from moving freely. [Effects of the Invention]

[0022] According to the present disclosure, it is possible to provide an electricity storage device that can suppress the occurrence of a short circuit even if electrolyte leaks from any one of a plurality of stacked cells. [Brief explanation of the drawings]

[0023]

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Figure 8

[0024] 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.

[0025] (Embodiment 1) Fig. 1 is a top view showing the electricity storage device according to embodiment 1. Fig. 2 is a cross-sectional view showing the electricity storage device according to embodiment 1. For convenience, the ceiling of the storage case is omitted from Fig. 1. Fig. 2 is a cross-sectional view taken along line II-II shown in Fig. 1. The electricity storage device 1 according to embodiment 1 will be described with reference to Figs. 1 and 2.

[0026] The electricity storage device 1 according to the first embodiment is mounted on a vehicle such as a hybrid vehicle that can run using at least one of the power of a motor and an engine, or an electrically powered vehicle that runs using driving force obtained from electrical energy.

[0027] The energy storage device 1 includes a plurality of cells 10, a plurality of spacers 20, a plurality of connection parts 30, and a housing case .

[0028] The storage case 40 has a generally box-like shape and accommodates a plurality of cells 10, a plurality of spacers 20, and a plurality of connection portions 30. The storage case 40 includes a ceiling portion 41 and a bottom portion 42 that face each other in the vertical direction (DR1 direction), and a peripheral wall portion that connects the peripheries of the ceiling portion 41 and the bottom portion 42. The peripheral wall portion has side walls 43, 44 that face each other in the horizontal direction (DR2 direction) perpendicular to the vertical direction.

[0029] The plurality of cells 10 are arranged in a vertical direction. An example of the cells 10 is a lithium ion battery. The cells 10 are so-called laminated cells.

[0030] The cell 10 includes an electrode stack 15, an exterior body 16, a positive electrode current collector plate 11 as a first terminal portion, and a negative electrode current collector plate 12 as a second terminal portion.

[0031] The electrode stack 15 includes, for example, a plurality of positive electrode sheets, a plurality of separators, and a plurality of negative electrode sheets. A separator is disposed between the positive electrode sheets and the negative electrode sheets.

[0032] The positive electrode sheet includes an aluminum foil and positive electrode composite layers formed on the front and back surfaces of the aluminum foil, with the aluminum foil having uncoated portions where the positive electrode composite layer is not formed.

[0033] The negative electrode sheet includes copper foil and negative electrode composite layers formed on the front and back surfaces of the copper foil, with the copper foil having uncoated portions where the negative electrode composite layer is not formed.

[0034] The exterior body 16 accommodates the electrode stack 15 and the electrolyte solution. The exterior body 16 is made of, for example, a laminate film. The laminate film covers a portion of the positive electrode current collector 11, a portion of the negative electrode current collector 12, and the electrode stack 15.

[0035] The positive electrode current collector 11 protrudes from the exterior body 16 to the outside. The positive electrode current collector 11 is connected to the uncoated portion of the positive electrode sheet. The positive electrode current collector 11 has a flat plate shape. The positive electrode current collector 11 is made of, for example, aluminum or an alloy containing aluminum as a main component.

[0036] The negative electrode current collector 12 protrudes from the exterior casing 16 to the outside. The negative electrode current collector 12 is connected to the uncoated portion of the negative electrode sheet. The negative electrode current collector 12 has a flat plate shape. The negative electrode current collector 12 is made of, for example, copper or an alloy containing copper as a main component.

[0037] The multiple cells 10 are arranged vertically so that the positive electrode current collector plates 11 and the negative electrode current collector plates 12 are alternately arranged vertically in each of a first protruding direction (AR1 direction) in which they protrude from the outer casing 16 when viewed from above and a second protruding direction (AR2 direction) different from the first protruding direction.

[0038] The multiple connection portions 30 electrically connect the positive electrode current collector plates 11 and negative electrode current collector plates 12 of adjacent cells 10 so that the multiple cells 10 are connected in series. The multiple connection portions 30 connect the positive electrode current collector plates 11 and negative electrode current collector plates 12 alternately on the first protruding direction side and the second protruding direction side. The multiple connection portions 30 include a first connection portion 31 and a second connection portion 32. The first connection portion 31 connects the positive electrode current collector plates 11 and negative electrode current collector plates 12 on the first protruding direction side. The second connection portion 32 connects the positive electrode current collector plates 11 and negative electrode current collector plates 12 on the second protruding direction side.

[0039] In this embodiment, the first protruding direction is a direction facing one side of a horizontal direction perpendicular to the up-down direction, and the second protruding direction is a direction facing the other side of the horizontal direction. That is, the second protruding direction is the opposite direction to the first protruding direction. Note that the relationship between the first protruding direction and the second protruding direction is not limited to the above, and the first protruding direction and the second protruding direction may intersect.

[0040] The positive electrode current collector 11 of the uppermost cell 10 is connected by a bus bar (not shown) to an external positive electrode terminal (not shown) provided outside the casing 40. The negative electrode current collector 12 of the lowermost cell 10 is connected by a bus bar (not shown) to an external negative electrode terminal (not shown) provided outside the casing 40.

[0041] The plurality of spacers 20 are alternately laminated with a plurality of cells 10 in the vertical direction. The plurality of spacers 20 are disposed between each of the adjacent cells in the vertical direction. As the spacer 20, for example, a member having electrolyte resistance such as urethane or EPDM (ethylene propylene rubber) is used. Thereby, when the electrolyte leaks from the cell 10, it is possible to suppress the spacer from being corroded by the electrolyte.

[0042] The spacer 20 has a plate shape. The spacer 20 has a first end portion 21 and a second end portion 22. The first end portion 21 and the second end portion 22 are located on both end sides in the lateral direction.

[0043] The first end portion 21 protrudes outward from the end portion 16a of the exterior body 16 in the first protruding direction. The first end portion 21 is provided with an extending portion 23 (first extending portion) extending downward. The extending portion 23 may be provided to be parallel to the vertical direction, or may be inclined so as to widen in the first protruding direction as it extends downward.

[0044] The second end portion 22 protrudes outward from the end portion 16b of the exterior body 16 in the second protruding direction. The second end portion 22 is provided with an extending portion 24 (second extending portion) extending downward. The extending portion 24 may be provided to be parallel to the vertical direction, or may be inclined so as to widen in the second protruding direction as it extends downward.

[0045] One of the first end portion 21 and the second end portion 22 of each of the plurality of spacers 20 faces one of the plurality of connection portions 30 in the lateral direction. The other of the first end portion 21 and the second end portion 22 of each spacer 20 does not face any of the plurality of connection portions 30 in the lateral direction.

[0046] More specifically, in the spacer 20 where the first end portion 21 faces the first connection portion 31 in the lateral direction on the first protruding direction side, the second end portion 22 does not face the second connection portion 32 in the lateral direction on the second protruding direction side. In the spacer 20 where the second end portion 22 faces the second connection portion 32 in the lateral direction on the second protruding direction side, the first end portion 21 does not face the first connection portion 31 in the lateral direction on the first protruding direction side.

[0047] Note that when viewed from above, the outer shape of the spacer 20 may be entirely larger than the exterior body 16. In this case, when viewed from above, both end portions of the spacer in the vertical direction and in the orthogonal direction orthogonal to the above-described lateral direction may protrude outside both ends of the exterior body 16 in the orthogonal direction.

[0048] FIG. 3 is a cross-sectional view showing an example in the case where electrolyte leaks from a cell in the power storage device according to Embodiment 1.

[0049] As shown in FIG. 3, when the exterior body 16 of the upper cell 10 among adjacent cells is damaged and the electrolyte L leaks out, the electrolyte L travels along the outer peripheral surface of the exterior body 16 and reaches the upper surface of the adjacent spacer 20 on the lower side. The electrolyte L that has reached the upper surface of the spacer 20 heads toward the extending portion 23 provided at the first end portion 21 of the spacer and / or the extending portion 24 provided at the second end portion 22. Since the first end portion 21 and the second end portion 22 protrude outside the exterior body 16 of the lower cell among adjacent cells, the electrolyte L heading toward the extending portions 23, 24 drips downward from the extending portions 23, 24 without traveling along the outer peripheral surface of the exterior body 16 of the lower cell 10. At this time, the flow path of the leaked electrolyte L is cut off. Thereby, it is possible to suppress the positive electrode current collector plate 11 and the negative electrode current collector plate 12 of adjacent cells from being electrically connected via the electrolyte L at an unintended location (more specifically, a location where the positive electrode current collector plate 11 and the negative electrode current collector plate 12 are arranged in the vertical direction but are not directly connected by the connection portion 30). As a result, it is possible to suppress a short circuit from occurring in the power storage device 1.

[0050] (Comparative Example) FIG. 4 is a cross-sectional view showing an example of a case where the electrolytic solution leaks from the cell in the storage device of the comparative example. With reference to FIG. 4, the storage device 1X in the comparative example will be described.

[0051] As shown in FIG. 4, the storage device 1X in the comparative example is different in that it does not include a plurality of spacers 20 when compared with the storage device 1 according to Embodiment 1. For other configurations, they are substantially the same.

[0052] As shown in FIG. 4, when no spacer is provided between adjacent cells 10, if the exterior body 16 of the upper cell 10 among the adjacent cells is damaged and the electrolytic solution L leaks out, the electrolytic solution L moves downward while spreading along the outer peripheral surface of the exterior body 16 of the upper cell 10 and the outer peripheral surface of the exterior body 16 of the lower cell 10. As a result, at an unintended location (more specifically, a location where the positive electrode current collector plate 11 and the negative electrode current collector plate 12 are arranged in the vertical direction although not directly connected by the connection portion 30), the positive electrode current collector plate 11 and the negative electrode current collector plate 12 of adjacent cells are electrically connected through the electrolytic solution L. As a result, in the storage device 1X in the comparative example, a short circuit may occur.

[0053] (Embodiment 2) FIG. 5 is a cross-sectional view showing the storage device according to Embodiment 2. With reference to FIG. 5, the storage device 1A according to Embodiment 2 will be described.

[0054] As shown in FIG. 5, the storage device 1A according to Embodiment 2 is different in the extending direction of the extending portions 23 and 24 when compared with the storage device 1 according to Embodiment 1. For other configurations, they are substantially the same. In Embodiment 2, the extending portions 23 and 24 extend upward.

[0055] The extensions 23 may be parallel to the vertical direction, or may be inclined to widen in a first protruding direction as they extend upward. Similarly, the extensions 24 may be parallel to the vertical direction, or may be inclined to widen in a second protruding direction as they extend upward.

[0056] In the second embodiment, the extension portions 23, 24 extend upward, so that even if the electrolyte leaks from an upper one of the adjacent cells 10, the electrolyte can be retained inside the extension portions 23, 24. This makes it possible to prevent the positive electrode current collector 11 and the negative electrode current collector 12 of the adjacent cells from being electrically connected via the electrolyte at an unintended location (more specifically, a location not connected by the connection portion 30). As a result, it is possible to prevent a short circuit from occurring in the electricity storage device 1A.

[0057] (Embodiment 3) 6 is a cross-sectional view showing a power storage device according to embodiment 3. With reference to FIG. 6, a power storage device 1B according to embodiment 3 will be described.

[0058] 6, electricity storage device 1B according to embodiment 3 differs from electricity storage device 1 according to embodiment 1 in that a retention portion 50 for retaining the electrolyte is provided at bottom 42 of the storage case. The other configurations are substantially the same.

[0059] For example, the reservoir 50 is configured as a groove provided on the inner surface of the bottom 42. Note that instead of the groove, the reservoir 50 may be configured as a collector that absorbs and collects the electrolyte. In this case, the collector is fixed to the inner surface of the bottom 42.

[0060] Even in the case of the above-described configuration, it is possible to obtain substantially the same effects as in embodiment 1. Furthermore, by providing retention portion 50, it is possible to prevent the electrolyte solution that has fallen to bottom portion 42 from moving freely.

[0061] (Fourth embodiment) 7 is a cross-sectional view showing a power storage device according to embodiment 4. With reference to FIG. 7, a power storage device 1C according to embodiment 4 will be described.

[0062] 7, an energy storage device 1C according to embodiment 4 differs from energy storage device 1 according to embodiment 1 in the configuration of spacer 20. The other configurations are substantially the same.

[0063] In embodiment 4, of the first end 21 and the second end 22 of each of the plurality of spacers 20, the end that does not face any of the plurality of connection portions 30 in the horizontal direction protrudes outward in the horizontal direction from the positive electrode current collector plates 11 and negative electrode current collector plates 12 that are arranged alternately in the vertical direction when viewed from above.

[0064] The end of the spacer on the side not facing any of the plurality of connection portions 30 in the horizontal direction may abut against the side wall portion 43 or the side wall portion 44 of the accommodating case 40 .

[0065] Even when configured as described above, substantially the same effects as in Embodiment 1 can be obtained. In Embodiment 4, when the electrolyte leaks from an upper cell 10 among adjacent cells 10, the electrolyte can be guided to the outside of the positive electrode current collector 11 and the negative electrode current collector 12 that are vertically aligned on the side where the positive electrode current collector 11 and the negative electrode current collector 12 are not connected by the connection portion 30. This further prevents the positive electrode current collector 11 and the negative electrode current collector 12 of adjacent cells from being electrically connected via the electrolyte in unintended locations (more specifically, locations not connected by the connection portion 30).

[0066] (Embodiment 5) 8 is a cross-sectional view showing a power storage device according to embodiment 5. With reference to FIG. 8, a power storage device 1D according to embodiment 5 will be described.

[0067] 8, energy storage device 1D according to embodiment 5 differs from energy storage device 1 according to embodiment 1 in that a bottom spacer 20D is provided between the lowest cell 10 and bottom 42 of casing 40. The other configurations are substantially the same.

[0068] Bottom-side spacer 20D has first protruding end portion 21D that protrudes outward beyond the end portion of exterior body 16 in a first protruding direction, and second protruding end portion 22D that protrudes outward beyond the end portion of exterior body 16 in a second protruding direction. First protruding end portion 21D is provided with upward extending portion 23D, and second protruding end portion 22D is provided with upward extending portion 24D.

[0069] The bottom spacer 20D is a spacer 20 arranged between adjacent cells 10, which is inverted vertically. This allows the inverted spacer 20 to be used as the bottom spacer 20D, enabling the use of common components. As a result, manufacturing costs can be reduced.

[0070] Even with the above-described configuration, substantially the same effects as those of the first embodiment can be obtained. Furthermore, by disposing bottom spacer 20D having upward extending portions 23D, 24D, electrolyte dropping toward bottom 42 can be blocked by extending portions 23D, 24D. Furthermore, the height positions of positive current collector 11 and negative current collector 12 of cell 10 located at the bottom can be increased by the thickness of bottom spacer 20D. This prevents electrolyte dropping to the bottom from affecting cell 10 located at the bottom.

[0071] 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]

[0072] 1, 1A, 1B, 1C, 1D, 1X Energy storage device, 10 Cell, 11 Positive electrode current collector, 12 Negative electrode current collector, 15 Electrode laminate, 16 Outer casing, 16a, 16b End, 20 Spacer, 20D Bottom spacer, 21 First end, 21D First protruding end, 22 Second end, 22D Second protruding end, 23, 23D, 24, 24D Extension portion, 30 Connection portion, 31 First connection portion, 32 Second connection portion, 40 Storage case, 41 Ceiling portion, 42 Bottom portion, 43, 44 Side wall portion, 50 Retention portion, L Electrolyte.

Claims

1. A plurality of cells arranged in the vertical direction, a plurality of spacers alternately laminated with the plurality of cells in the vertical direction and each disposed between adjacent cells in the vertical direction, each of the plurality of cells includes an exterior body that houses an electrolytic solution therein, and a first terminal portion and a second terminal portion that protrude from the exterior body, the first terminal portion and the second terminal portion are alternately arranged side by side in the vertical direction in each of a first protruding direction protruding from the exterior body when viewed from above and a second protruding direction different from the first protruding direction, each of the plurality of spacers has a plate shape, each of the plurality of spacers includes a first end portion protruding outward from an end portion of the exterior body in the first protruding direction and a second end portion protruding outward from the end portion of the exterior body in the second protruding direction, each of the plurality of spacers is disposed between the first terminal portion and the second terminal portion spaced apart in the vertical direction on the first end portion side, and includes a first opposing portion facing the first terminal portion and the second terminal portion in the vertical direction; and on the second end portion side, is disposed between the first terminal portion and the second terminal portion spaced apart in the vertical direction, and includes a second opposing portion facing the first terminal portion and the second terminal portion in the vertical direction, a space is formed in the vertical direction between the first terminal portion and the second terminal portion spaced apart in the vertical direction on the first end portion side, a portion of each side surface of the adjacent cells located on the first end portion side and positioned between the first terminal portion and the second terminal portion, and the first opposing portion, a space is formed in the vertical direction between the first terminal portion and the second terminal portion spaced apart in the vertical direction on the second end portion side, a portion of each side surface of the adjacent cells located on the second end portion side and positioned between the first terminal portion and the second terminal portion, and the second opposing portion, a power storage device, wherein each of the first end portion and the second end portion is provided with an extending portion extending toward one side in the vertical direction.

2. The power storage device according to claim 1, wherein the extending portion extends downward.

3. The power storage device according to claim 1, wherein the extending portion extends upward.

4. The spacer has electrolyte resistance, and the power storage device according to any one of claims 1 to 3.

5. It has a bottom, a housing case for housing the plurality of cells and the plurality of spacers, and a bottom-side spacer disposed between the cell located at the lowermost position and the bottom, wherein the bottom-side spacer has a first protruding end portion that protrudes outward from the end portion of the exterior body in the first protruding direction and a second protruding end portion that protrudes outward from the end portion of the exterior body in the second protruding direction, and an extending portion that extends upward is provided at each of the first protruding end portion and the second protruding end portion, and the power storage device according to any one of claims 1 to 3.

6. It further includes a plurality of connection portions that electrically connect the first terminal portions and the second terminal portions of the adjacent cells so that the plurality of cells are connected in series, wherein the first protruding direction is a direction facing one side in the lateral direction orthogonal to the vertical direction, the second protruding direction is a direction facing the other side in the lateral direction, one of the first end portion and the second end portion of each of the plurality of spacers faces one of the plurality of connection portions in the lateral direction, and the other of the first end portion and the second end portion of each of the plurality of spacers protrudes outward in the lateral direction from the first terminal portion and the second terminal portion that are arranged alternately in the vertical direction when viewed from above, and the power storage device according to any one of claims 1 to 3.

7. It has a bottom and further includes a housing case for housing the plurality of cells and the plurality of spacers, wherein a retention portion for retaining the electrolyte leaked from at least any one of the plurality of cells is provided on the bottom, and the power storage device according to any one of claims 1 to 3.

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