Electric energy storage device

Abstract

To provide a power storage device which can suppress an increase in size or weight while protecting power storage elements.SOLUTION: A power storage device 10 comprises: a first power storage element (a power storage element 201) and a second power storage element (a power storage element 204) which are arranged in a first direction (an X-axis direction); and a first spacer (a spacer 320) disposed between the first power storage element and the second power storage element. The first power storage element has: an electrode terminal 240; and a container 210 in which the electrode terminal 240 is disposed. Viewed from the first direction, the first spacer protrudes from an edge, of the container 210, which is in a second direction (a Y-axis direction) perpendicular to the first direction and is on a side different from that of the electrode terminal 240. In addition, the first spacer is shorter than the container 210 in a third direction (a Z-axis direction) perpendicular to the first direction and the second direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a power storage device including a power storage element and a spacer.

Background Art

[0002] Conventionally, a power storage device including a power storage element and a spacer has been widely known. For example, Patent Document 1 discloses a power supply device (power storage device) including a plurality of secondary battery cells (power storage elements) arranged adjacent to each other and separators (spacers) interposed between adjacent secondary battery cells.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a power storage device having the above-described conventional configuration, when an impact is applied from the side of the power storage element, there is a desire to suppress damage to the power storage element. However, providing a member for protecting the power storage element to protect the power storage element may cause an increase in the size or weight of the power storage device. For this reason, a power storage device that can suppress an increase in size or weight while protecting the power storage element is desired.

[0005] The present invention has been made by the inventors of the present application newly paying attention to the above problems, and an object thereof is to provide a power storage device that can suppress an increase in size or weight while protecting a power storage element.

Means for Solving the Problems

[0006] To achieve the above object, a power storage device according to one aspect of the present invention includes a first power storage element and a second power storage element arranged in a first direction, and a first spacer disposed between the first power storage element and the second power storage element. The first power storage element has an electrode terminal and a container in which the electrode terminal is disposed. The first spacer projects from an edge of the container in a second direction orthogonal to the first direction as viewed from the first direction, on a side different from the electrode terminal, and has a length shorter than that of the container in a third direction orthogonal to the first direction and the second direction.

[0007] According to this, in the power storage device, the first spacer between the first power storage element and the second power storage element arranged in the first direction projects from an edge of the container of the first power storage element in the second direction, on a side different from the electrode terminal, as viewed from the first direction, and has a length shorter than that of the container in the third direction. In this way, by projecting the first spacer from an edge of the container of the first power storage element in the second direction, on a side different from the electrode terminal, the first power storage element can be protected against an impact from the second direction to the first power storage element. Further, there is a problem that the first spacer becomes larger in size and increases in weight by projecting the first spacer from the edge of the container of the first power storage element in the second direction. In particular, in order to improve the strength of the first spacer, the thickness of the first spacer is increased or the first spacer is formed of metal, resulting in an increase in the size and weight of the first spacer. Therefore, the first spacer is formed to have a length shorter than that of the container of the first power storage element in the third direction. Thereby, an increase in the size or weight of the first spacer can be suppressed. Therefore, in the power storage device, it is possible to suppress an increase in size or weight while protecting the power storage element.

[0008] The first spacer may project from edges on both sides of the container in the second direction, on a side different from the electrode terminal, as viewed from the first direction.

[0009] According to this, in the power storage device, the first spacer protrudes from the edge portions on both sides in the second direction of the container of the first power storage element, so that the first power storage element can be effectively protected against impacts from the second direction to the first power storage element.

[0010] The first spacer may be arranged such that, in the third direction, the center is closer to at least one of the electrode terminal of the first power storage element, the gas discharge valve, the joint portion of the container, and the joint portion of the exterior body in which the first power storage element and the first spacer are accommodated than the center of the container.

[0011] In the power storage element, a configuration for protecting the electrode terminal, the gas discharge valve, or the joint portion of the container is preferable, and in the power storage device, a configuration for protecting the joint portion of the exterior body is preferable. For this reason, the first spacer is arranged such that the center is closer to at least one of the electrode terminal of the first power storage element, the gas discharge valve, the joint portion of the container, and the joint portion of the exterior body of the power storage device than the center of the container of the first power storage element. Thereby, at least one of the first power storage element and the exterior body can be effectively protected.

[0012] Furthermore, a side plate arranged in the second direction of the first power storage element, the second power storage element, and the first spacer may be provided, and the center of the side plate may be arranged in the third direction in the same direction as the center of the first spacer with respect to the center of the container.

[0013] When the power storage device is provided with a side plate, the side plate is also arranged such that the center is located in the same direction as the center of the first spacer with respect to the center of the container of the first power storage element. Thereby, at least one of the electrode terminal of the first power storage element, the gas discharge valve, the joint portion of the container, and the joint portion of the exterior body of the power storage device can be effectively protected by the side plate.

[0014] Furthermore, an insulating second spacer arranged between the first power storage element and the first spacer may be provided.

[0015] According to this, separately from the first spacer for the purpose of protecting the energy storage element, an insulating second spacer is arranged for the purpose of insulating the energy storage element. For example, when the first spacer is formed of a conductive member such as metal, by arranging the second spacer between the first energy storage element and the first spacer, insulation between the first energy storage element and the first spacer can be achieved. Even when the first spacer is formed of an insulating member, if the first spacer is not configured to provide insulation between the first energy storage element and the second energy storage element, by arranging the second spacer, insulation between the first energy storage element and the second energy storage element can be achieved. Thus, in the energy storage device, the energy storage element can be protected.

[0016] The second spacer may be longer than the first spacer in the third direction.

[0017] According to this, by forming the insulating second spacer longer than the first spacer, improvement in the insulation property of the energy storage element can be achieved. For example, when the first spacer is formed of a conductive member such as metal, by forming the second spacer longer than the first spacer, improvement in the insulation property between the first energy storage element and the first spacer can be achieved. Even when the first spacer is formed of an insulating member, since the first spacer is shorter than the container in the third direction, there is a possibility that the first spacer cannot sufficiently provide insulation between the first energy storage element and the second energy storage element. Therefore, by arranging a second spacer longer than the first spacer, improvement in the insulation property between the first energy storage element and the second energy storage element can be achieved. Thus, in the energy storage device, the energy storage element can be protected.

[0018] The present invention can be realized not only as such an energy storage device, but also as the first spacer, or as a combination of the first spacer and the second spacer.

Effect of the Invention

[0019] According to the energy storage device in the present invention, while protecting the energy storage element, an increase in size or weight can be suppressed.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0021] Hereinafter, with reference to the drawings, a power storage device according to an embodiment (including its modifications) of the present invention will be described. Note that each of the embodiments described below shows comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, manufacturing processes, order of manufacturing processes, etc. shown in the following embodiments are examples and are not intended to limit the present invention. In each figure, the dimensions and the like are not precisely illustrated. In each figure, the same or similar components are denoted by the same reference numerals.

[0022] In the following description and drawings, the arrangement direction of a plurality of power storage elements, the opposing direction of the long side surfaces of the containers of the power storage elements, the arrangement direction of a plurality of spacers, the arrangement direction of the power storage elements and the spacers, or the arrangement direction of a pair of end plates is defined as the X-axis direction. The arrangement direction of a pair (positive electrode side and negative electrode side) of electrode terminals in one power storage element, the opposing direction of the short side surfaces of the container of the power storage element, or the arrangement direction of a pair of side plates is defined as the Y-axis direction. The arrangement direction of the main body of the exterior body and the exterior body lid of the power storage device, the arrangement direction of the main body of the container of the power storage element and the container lid, the arrangement direction of the power storage element and the bus bar, or the vertical direction is defined as the Z-axis direction. These X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect (orthogonal in this embodiment) with each other. Note that depending on the usage mode, the Z-axis direction may not be the vertical direction, but hereinafter, for convenience of explanation, the Z-axis direction will be described as the vertical direction.

[0023] In the following description, for example, the X-axis plus direction indicates the direction of the arrow on the X-axis, and the X-axis minus direction indicates the direction opposite to the X-axis plus direction. The same applies to the Y-axis direction and the Z-axis direction. Hereinafter, the X-axis direction may also be referred to as the first direction, the Y-axis direction may also be referred to as the second direction, and the Z-axis direction may also be referred to as the third direction. Furthermore, expressions indicating relative directions or postures such as parallel and orthogonal include cases where they are not strictly in that direction or posture. For example, two directions being orthogonal means not only that the two directions are completely orthogonal but also that they are substantially orthogonal, that is, including a difference of, for example, about several percent. In the following description, when the expression "insulation" is used, it means "electrical insulation".

[0024] (Embodiment) [General description of the power storage device 10] First, a general description of the power storage device 10 in the present embodiment will be given. FIG. 1 is a perspective view showing the appearance of the power storage device 10 according to the present embodiment. FIG. 2 is an exploded perspective view showing each component when the power storage device 10 according to the present embodiment is disassembled. FIG. 3 is an exploded perspective view showing each component when the power storage device 10 according to the present embodiment is further disassembled. Note that FIG. 3 is an exploded perspective view showing the components other than the exterior body 100 and the bus bar 700 in the power storage device 10.

[0025] The power storage device 10 is a device that can charge electricity from the outside and discharge electricity to the outside. In the present embodiment, it has a substantially rectangular parallelepiped shape. For example, the power storage device 10 is a battery module (battery pack) used for power storage applications or power supply applications, etc. Specifically, the power storage device 10 is used, for example, as a battery for driving a moving body such as an automobile, a motorcycle, a watercraft, a ship, a snowmobile, an agricultural machine, a construction machine, or a railway vehicle for electric railways for engine starting, etc. Examples of the above-mentioned automobile include an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a gasoline vehicle. Examples of the above-mentioned railway vehicle for electric railways include a train, a monorail, a linear motor car, and a hybrid train equipped with both a diesel engine and an electric motor. Further, the power storage device 10 can also be used as a stationary battery used for household or business use, etc.

[0026] As shown in FIG. 1, the power storage device 10 includes an exterior body 100. As shown in FIGS. 2 and 3, inside the exterior body 100, a plurality of power storage elements 200, a plurality of spacers 300 (310 to 340), a pair of end plates 400 (401, 402), a pair of side plates 500 (501, 502), a plurality of bus bars 700, and the like are accommodated. In addition to the above components, the power storage device 10 may further include a bus bar frame on which the bus bar 700 is placed, a circuit board for monitoring the charge and discharge states of the power storage elements 200, electrical devices such as fuses, relays, and connectors, and an exhaust portion for exhausting the gas discharged from the power storage elements 200 to the outside of the exterior body 100.

[0027] The exterior body 100 is a box-shaped (substantially rectangular parallelepiped shape) container (module case) that constitutes the housing (outer shell) of the power storage device 10. The exterior body 100 is disposed outside a plurality of power storage elements 200, a plurality of spacers 300, a pair of end plates 400, a pair of side plates 500, a plurality of bus bars 700, and the like, and fixes the plurality of power storage elements 200 and the like at predetermined positions to protect them from impacts and the like. The exterior body 100 is formed of, for example, an insulating member such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene·perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyether sulfone (PES), ABS resin, or a composite material thereof, or a metal with insulating coating. Thereby, the exterior body 100 avoids the power storage elements 200 and the like from coming into contact with external metal members and the like. Note that the exterior body 100 may be formed of a conductive member such as metal as long as the insulation of the power storage elements 200 and the like is maintained.

[0028] The exterior body 100 includes an exterior body main body 110 that constitutes the main body of the exterior body 100 and an exterior body lid 120 that constitutes the lid of the exterior body 100. The exterior body main body 110 is a bottomed rectangular cylindrical housing (case) with an opening formed therein, and houses a power storage element 200 and the like. The exterior body lid 120 is a flat rectangular member that closes the opening of the exterior body main body 110. A pair of (positive electrode side and negative electrode side) external terminals 121 are provided on the exterior body lid 120. The power storage device 10 charges electricity from the outside and discharges electricity to the outside through this pair of external terminals 121.

[0029] After the exterior body 100 houses the power storage element 200 and the like inside, the exterior body main body 110 and the exterior body lid 120 are joined (adhered) to each other by an adhesive or the like, and a joint portion 130 is formed, so that the interior has a structure that is substantially sealed. In the present embodiment, the exterior body main body 110 and the exterior body lid 120 are joined over the entire circumference of the opening of the exterior body main body 110, and a square annular joint portion 130 that surrounds the periphery (entire circumference) of the exterior body 100 is formed. Note that the joint portion 130 is not limited to being formed by joining (adhering) with an adhesive. For example, it may be formed by joining (welding) such as heat sealing or ultrasonic welding, or by mechanical joining such as caulking or bolt fastening.

[0030] The energy storage element 200 is a secondary battery (single cell) that can charge and discharge electricity, and more specifically, is a non-aqueous electrolyte secondary battery such as a lithium-ion secondary battery. The energy storage element 200 has a flat rectangular parallelepiped shape (rectangular shape), and in the present embodiment, eight energy storage elements 200 are arranged side by side in the X-axis direction. Note that the energy storage element 200 may have any shape such as a polygonal prism shape, an elliptical cylinder shape, an elliptical column shape, a cylindrical shape, etc. other than the flat rectangular parallelepiped shape, and the size of the energy storage element 200 and the number of energy storage elements 200 to be arranged are not particularly limited. The energy storage element 200 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, or may be a capacitor. The energy storage element 200 may be a primary battery in which electricity stored without the user charging can be used instead of a secondary battery. The energy storage element 200 may be a battery using a solid electrolyte. The energy storage element 200 may be a pouch-type energy storage element. A detailed description of the configuration of the energy storage element 200 will be described later.

[0031] The bus bar 700 is a flat plate-shaped and rectangular member connected to the energy storage element 200. The bus bar 700 is disposed above the plurality of energy storage elements 200 and is connected (joined) to the electrode terminals 240 (see FIGS. 2, 4, etc.) of the plurality of energy storage elements 200 and the external terminal 121. That is, the bus bar 700 connects the electrode terminals 240 of the plurality of energy storage elements 200 to each other and connects the electrode terminal 240 of the end energy storage element 200 and the external terminal 121.

[0032] In this embodiment, the bus bar 700 and the electrode terminal 240 are connected (joined) by welding, and the bus bar 700 and the external terminal 121 are connected (joined) by bolt fastening via another bus bar, but the connection form is not particularly limited. The bus bar 700 is formed of, for example, a metallic conductive member such as aluminum, an aluminum alloy, copper, a copper alloy, nickel, or a combination thereof, or a conductive member other than metal. In this embodiment, the bus bar 700 connects two power storage elements 200 in parallel to form four sets of power storage element groups, and connects the four sets of power storage element groups in series. Note that the connection form of the bus bar 700 is not particularly limited, and a plurality of power storage elements 200 may be connected in series in any combination and may be arranged to be connected in parallel.

[0033] The spacer 300 is arranged on the side (the +X-axis direction or the -X-axis direction) of the power storage element 200 and is a member that insulates the power storage element 200 from other members. The spacer 300 also has a function of holding the power storage element 200 and positioning the power storage element 200. Here, among the plurality of spacers 300, the spacer 300 arranged between the power storage elements 200 connected in parallel within one set of power storage element groups is also called a spacer 310, and the three spacers 300 arranged between the power storage element groups connected in series are also called spacers 320, 330, and 340. Among the plurality of spacers 300, the spacer 300 at the end, that is, the spacer 300 between the end power storage element 200 (power storage element group) and the end plate 400, has the same configuration as the above spacer 330, and thus the spacer 300 at the end is also called a spacer 330. In this way, the plurality of power storage elements 200 and the plurality of spacers 300 (spacers 310 to 340) are arranged side by side in the X-axis direction (the first direction).

[0034] The spacer 310 is a flat and rectangular spacer that is disposed between two adjacent power storage elements 200 that are connected in parallel. The spacer 310 is formed of a member having insulating properties such as any resin material that can be used for the above-described exterior body 100. The spacer 310 is disposed at the central portion of the two power storage elements 200, and by pressing the central portion, it suppresses the movement of the power storage element 200 or the movement of the electrode body within the container of the power storage element 200, and has functions such as protecting the power storage element 200. For example, the spacer 310 located at the end in the positive X-axis direction among a plurality of spacers 310 is disposed between two power storage elements 201 and 202 that are connected in parallel within a group of power storage elements located at the end in the positive X-axis direction among the plurality of power storage elements 200. In the present embodiment, four spacers 310 are disposed corresponding to four sets of power storage element groups. However, when the number of power storage element groups is other than four sets, the number of spacers 310 is also appropriately changed according to the number of power storage element groups. Further, within one set of power storage element groups, when three or more power storage elements 200 are connected in parallel and disposed, the number of spacers 310 is also appropriately changed according to the number of power storage elements 200.

[0035] The spacer 310 is joined to the power storage element 200 by a joining member 311. In the present embodiment, the joining member 311 is a double-sided tape, and a plurality (two) of joining members 311 arranged in the Z-axis direction are disposed on each of the surfaces on both sides in the X-axis direction of the spacer 310. Thereby, the spacer 310 is joined (adhered) and fixed to the two power storage elements 200 on both sides in the X-axis direction, and positions of the two power storage elements 200 are regulated. Note that the joining member 311 may be an adhesive or the like instead of a double-sided tape, and the arrangement position, number, shape, etc. of the joining member 311 are not particularly limited. A detailed description of the configuration of the spacer 310 will be described later.

[0036] Spacers 320 to 340 (excluding the end spacer 330) are spacers that are disposed between two adjacent power storage elements 200 that are connected in series. The spacers 320 to 340 have functions such as insulating between the two power storage elements 200 and protecting the power storage elements 200 against external impacts. In the present embodiment, the spacers 320 to 340 are disposed between power storage element groups each composed of two power storage elements 200 connected in parallel (between two adjacent power storage element groups connected in series).

[0037] For example, the spacers 320 to 340 located at the end in the +X axis direction among the plurality of spacers 320 to 340 (excluding the end spacer 330) are disposed between two serially connected power storage element groups located at the end in the +X axis direction among the plurality of power storage element groups. That is, the spacers 320 to 340 are disposed between the power storage element group composed of the power storage elements 201 and 202 and the power storage element group composed of the power storage elements 203 and 204 (specifically, between the power storage elements 201 and 204). In the present embodiment, three sets of spacers 320 to 340 are disposed corresponding to four sets of power storage element groups. However, when the number of power storage element groups is other than four sets, the number of spacers 320 to 340 is also appropriately changed according to the number of power storage element groups.

[0038] The spacer 320 is disposed between two spacers 330 (and 340), and is a flat plate-like and substantially rectangular spacer with higher rigidity than the spacers 330 (and 340). The spacer 320 is formed of a metallic member such as, for example, aluminum, an aluminum alloy, iron, stainless steel, or a plated steel sheet. Note that the material of the spacer 320 is not particularly limited, and it may be formed of a highly rigid insulating member or may be subjected to an insulation treatment. The spacer 330 is a plate-like and substantially rectangular insulating spacer disposed between the spacer 320 (and 340) and the power storage element 200. Specifically, the spacer 330 faces the long side surface 213 of a container 210, which will be described later, of the power storage element 200, and is disposed in a state of being in contact with the spacer 320 (and 340) and the long side surface 213. The spacer 330 is formed of a member having insulation properties such as any resin material that can be used for the exterior body 100 described above. The spacer 340 is a flat plate-like and rectangular spacer disposed in a recess 333 formed in the central portion of the spacer 330 (see FIG. 7). Specifically, the spacer 340 is a heat insulating material and is formed of a member having heat insulating properties such as glass fiber or a dama material.

[0039] With such a configuration, the spacers 320 to 340 ensure the strength with the spacer 320 to protect the power storage element 200 between the power storage element groups, provide insulation between the power storage element groups with the two spacers 330, and provide heat insulation between the power storage element groups with the two spacers 340. A more detailed description of the configuration of the spacers 320 to 340 will be given later.

[0040] As described above, the spacer 330 is also disposed between the power storage element 200 at the end (the power storage element group at the end) and the end plates 400 (401, 402). Thereby, insulation can be achieved between the power storage element 200 at the end (the power storage element group at the end) and the end plates 400 (401, 402).

[0041] The end plate 400 and the side plate 500 are restraining members that compress (restrain) the power storage elements 200 from the outside in the arrangement direction (X-axis direction) of the plurality of power storage elements 200. That is, the end plate 400 and the side plate 500 sandwich the plurality of power storage elements 200 from both sides in the arrangement direction, thereby compressing (restraining) each power storage element 200 included in the plurality of power storage elements 200 from both sides in the arrangement direction. The end plate 400 and the side plate 500 are formed of metal members such as steel or stainless steel from the viewpoint of ensuring strength, etc., but their materials are not particularly limited. For example, they may be formed of highly strong insulating members, or the metal members may be subjected to insulation treatment.

[0042] The end plate 400 is disposed on both sides in the X-axis direction of the plurality of power storage elements 200 and the plurality of spacers 300 (310 to 340), and is a plate-like member (clamping member) that sandwiches and holds the plurality of power storage elements 200, etc. from both sides in their arrangement direction (X-axis direction). Here, among the pair of end plates 400, the end plate 400 on the +X-axis direction side is also referred to as the end plate 401, and the end plate 400 on the -X-axis direction side is also referred to as the end plate 402. That is, the pair of end plates 401 and 402 are disposed at positions that sandwich the plurality of power storage elements 200 and the plurality of spacers 300 in the X-axis direction (the lamination direction of the electrode plates of the power storage elements 200), and restrain them.

[0043] The side plate 500 is a plate-like and long restraining member (restraining plate) disposed in the Y-axis direction (the second direction orthogonal to the first direction) of the plurality of power storage elements 200 and the plurality of spacers 300 (310 to 340). Specifically, both ends of the side plate 500 are attached to the pair of end plates 400 (401, 402), and by connecting the pair of end plates 400, the plurality of power storage elements 200 and the plurality of spacers 300 (310 to 340) are restrained. That is, the side plate 500 is extended and disposed in the X-axis direction so as to straddle the plurality of power storage elements 200 and the plurality of spacers 300, and imparts a restraining force in their arrangement direction (X-axis direction) to the plurality of power storage elements 200, etc.

[0044] In this embodiment, a pair of side plates 500 are arranged on both sides of the plurality of power storage elements 200 and the plurality of spacers 300 (310 to 340) in the Y-axis direction. In this embodiment, the pair of side plates 500 are arranged closer to the positive Z-axis direction on both sides in the Y-axis direction of the plurality of power storage elements 200 and the like. And each of the pair of side plates 500 is attached to the Y-axis direction ends of the pair of end plates 400 at both ends in the X-axis direction. Thereby, the pair of side plates 500, together with the pair of end plates 400, sandwich and restrain the plurality of power storage elements 200 and the like from both sides in the X-axis direction and both sides in the Y-axis direction.

[0045] Specifically, the side plate 500 is connected (joined) to the end plates 400 (401, 402) by a plurality of (two in this embodiment) connecting members 500a arranged in the Z-axis direction. In this embodiment, the connecting member 500a is a bolt and is fastened by screwing with the nuts of the end plates 400. Note that the connection (joining) of the side plate 500 to the end plate 400 is not limited to fixing by bolt fastening, and may be joined by welding or adhesion or the like. Among the pair of side plates 500, the side plate 500 on the positive Y-axis direction side is also referred to as the side plate 501, and the side plate 500 on the negative Y-axis direction side is also referred to as the side plate 502.

[0046] [Description of the Power Storage Element 200] Next, the configuration of the power storage element 200 will be described in detail. FIG. 4 is a perspective view showing the configuration of the power storage element 200 according to this embodiment. Specifically, FIG. 4 shows an enlarged view of the appearance of one of the plurality of power storage elements 200 shown in FIG. 3. Since all of the plurality of power storage elements 200 have the same configuration, the configuration of one power storage element 200 will be described in detail below.

[0047] As shown in FIG. 4, the power storage element 200 includes a container 210, a pair of (positive electrode side and negative electrode side) electrode terminals 240, and an upper gasket 250. Further, inside the container 210, a lower gasket, an electrode body, a pair of (positive electrode side and negative electrode side) current collectors, an electrolytic solution (non-aqueous electrolyte), etc. are accommodated, but the illustration thereof is omitted. The type of the electrolytic solution is not particularly limited as long as it does not impair the performance of the power storage element 200, and various types can be selected.

[0048] In addition to the above components, the power storage element 200 may have a spacer disposed on the side or below of the electrode body, an insulating film that wraps the electrode body, etc. Further, an insulating film (such as a shrink tube) that covers the outer surface of the container 210 may be disposed around the container 210. The material of the insulating film is not particularly limited as long as it can ensure the insulation required for the power storage element 200. Examples thereof include insulating resins such as PC, PP, PE, PPS, PET, PBT, or ABS resin, epoxy resin, Kapton (registered trademark), Teflon (registered trademark), silicon, polyisoprene, and polyvinyl chloride.

[0049] The container 210 is a rectangular parallelepiped (square or box-shaped) case having a container body 220 with an opening formed therein and a container lid 230 that closes the opening of the container body 220. The container body 220 is a rectangular cylindrical member with a bottom that constitutes the main body of the container 210, and an opening is formed on the +Z-axis direction side. The container lid 230 is a rectangular plate-like member that constitutes the lid portion of the container 210, and is extended and disposed in the Y-axis direction on the +Z-axis direction side of the container body 220. The container lid 230 is provided with a gas discharge valve 231 that releases the pressure when the pressure inside the container 210 rises excessively, and a liquid injection portion 232 for injecting the electrolytic solution into the container 210. The material of the container 210 (container body 220 and container lid 230) is not particularly limited, and can be, for example, a weldable (joinable) metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel sheet, but resin can also be used.

[0050] After the electrode body or the like is accommodated inside the container body 220, the container body 220 and the container lid 230 are joined by welding or the like to form a joint portion 215, so that the interior is sealed. In the present embodiment, laser light is irradiated from the side (X-axis direction and Y-axis direction) of the container 210, and the container body 220 and the container lid 230 are joined by laser welding to form the joint portion 215. The joint portion 215 is a rectangular annular joint portion formed so as to surround the periphery (entire circumference) of the container 210.

[0051] With such a configuration, the container 210 has a terminal arrangement surface 211 on the upper surface on the +Z-axis direction side, a pair of short side surfaces 212 on the side surfaces on both sides in the Y-axis direction, a pair of long side surfaces 213 on the side surfaces on both sides in the X-axis direction, and a bottom surface 214 on the lower surface on the -Z-axis direction side. The terminal arrangement surface 211 is a rectangular flat portion on the +Z-axis direction side of the container lid 230 where the electrode terminals 240 are arranged, and is arranged adjacent to the short side surfaces 212 and the long side surfaces 213. The short side surface 212 is a rectangular flat portion forming the short side surface of the container 210, and is arranged to face the side plate 500 in the Y-axis direction. The short side surface 212 is adjacent to the long side surface 213 and the bottom surface 214, and has a smaller area than the long side surface 213. The long side surface 213 is a rectangular flat portion forming the long side surface of the container 210, and is arranged to face the long side surface 213 of the container 210 of the adjacent power storage elements 200 or the spacer 300 in the X-axis direction. The long side surface 213 is adjacent to the short side surface 212 and the bottom surface 214, and has a larger area than the short side surface 212. The bottom surface 214 is a rectangular flat portion forming the bottom surface of the container 210, and faces the bottom surface of the exterior body main body 110 in the Z-axis direction, and is arranged adjacent to the long side surface 213 and the short side surface 212.

[0052] The electrode terminal 240 is at the end of the container 210 in the Z-axis direction (the third direction orthogonal to the first and second directions), specifically, the terminal members (positive electrode terminal and negative electrode terminal) of the power storage element 200 disposed on the container lid 230 of the container 210. The electrode terminal 240 is electrically connected to the positive and negative electrode plates of the electrode body via a current collector. That is, the electrode terminal 240 is a metal member for leading out the electricity stored in the electrode body to the external space of the power storage element 200 and introducing electricity into the internal space of the power storage element 200 to store electricity in the electrode body. The electrode terminal 240 is formed of aluminum, an aluminum alloy, copper, a copper alloy, or the like.

[0053] The electrode body is a power storage element (power generation element) formed by laminating a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate has a positive electrode active material layer formed on a positive electrode base material layer that is a current collecting foil made of a metal such as aluminum or an aluminum alloy. The negative electrode plate has a negative electrode active material layer formed on a negative electrode base material layer that is a current collecting foil made of a metal such as copper or a copper alloy. As the active material used in the positive electrode active material layer and the negative electrode active material layer, any known material can be appropriately used as long as it can occlude and release lithium ions. As the separator, a microporous sheet or nonwoven fabric made of resin can be used. In the present embodiment, the electrode body is formed by laminating electrode plates (positive electrode plate and negative electrode plate) in the X-axis direction. Note that the electrode body may be a wound-type electrode body formed by winding electrode plates (positive electrode plate and negative electrode plate), a laminated-type (stack-type) electrode body formed by laminating a plurality of flat electrode plates, or a bellows-type electrode body formed by folding the electrode plates in a bellows shape.

[0054] The current collector is a conductive member (positive current collector and negative current collector) that is electrically connected to the electrode terminal 240 and the electrode body. The positive current collector is formed of aluminum, an aluminum alloy, or the like, similar to the positive electrode base material layer of the positive electrode plate, and the negative current collector is formed of copper, a copper alloy, or the like, similar to the negative electrode base material layer of the negative electrode plate. The upper gasket 250 is a gasket that is disposed between the container lid 230 and the electrode terminal 240, insulates and seals the space between the container lid 230 and the electrode terminal 240. The lower gasket is a gasket that is disposed between the container lid 230 and the current collector, insulates and seals the space between the container lid 230 and the current collector. The upper gasket 250 and the lower gasket may be formed of any material as long as they have insulating properties.

[0055] Thus, inside the container 210, the current collector and the lower gasket are disposed at the end in the +Z-axis direction. For this reason, in the Z-axis direction, the center of the electrode body is disposed in the -Z-axis direction relative to the center of the container 210. The center of the electrode body is the centroid of the surface facing in the X-axis direction of the electrode body (when the surface is not a flat surface, the surface obtained by projecting the electrode body onto the YZ plane). The center of the container 210 is the centroid of the surface facing in the X-axis direction of the container 210 (in this embodiment, the long side surface 213).

[0056] [Description of the spacer 300] Next, the configuration of the spacer 300 (310 to 340) will be described in detail. In the following, since each of the spacers 310 to 340 included in the power storage device 10 has the same configuration, the description will be centered on the spacer 310 located at the end in the +X-axis direction and the set of spacers 320 to 340 located at the end in the +X-axis direction.

[0057] As described above, the power storage elements 201 to 204 are arranged side by side in the X-axis direction. The power storage element 204 is arranged at a position where it sandwiches the power storage element 201 with the power storage element 202. The power storage element 203 is arranged at a position where it sandwiches the power storage element 204 with the power storage element 201. The power storage elements 201 and 202 are connected in parallel, and the power storage elements 203 and 204 are connected in series with the power storage elements 201 and 202. The spacer 310 is arranged between the power storage elements 201 and 202. The spacers 320 and 330 are arranged between the power storage elements 201 and 204. Specifically, the spacer 320 is arranged between the two spacers 330, and the spacer 330 is arranged between the power storage element 201 or the power storage element 204 and the spacer 320.

[0058] Here, the power storage element 201 is an example of the first power storage element, and the power storage element 204 is an example of the second power storage element. The spacer 320 is an example of the first spacer, and the spacer 330 is an example of the second spacer. That is, the first power storage element (power storage element 201) and the second power storage element (power storage element 204) are arranged side by side in the X-axis direction (first direction). The first spacer (spacer 320) is arranged between the first power storage element (power storage element 201) and the second power storage element (power storage element 204). The second spacer (spacer 330) is arranged between the first power storage element (power storage element 201) or the second power storage element (power storage element 204) and the first spacer (spacer 320). The side plate 500 is arranged in the Y-axis direction (second direction) of the first power storage element (power storage element 201), the second power storage element (power storage element 204), the first spacer (spacer 320), and the second spacer (spacer 330).

[0059] [3.1 Description of Spacer 310] First, the configuration of the spacer 310 will be described in detail. FIG. 5 is a front view showing the arrangement position of the spacer 310 with respect to the power storage element 200 according to the present embodiment. Specifically, FIG. 5 shows the configuration when the state in which the spacer 310 is arranged on the power storage element 200 is viewed from the X-axis direction. FIG. 6 is a cross-sectional view showing a state in which the spacer 310 according to the present embodiment is sandwiched between two power storage elements 200 (201 and 202). Specifically, FIG. 6(a) shows the configuration when the state in which two power storage elements 200 (201 and 202) are arranged on both sides of the spacer 310 is cut by a plane parallel to the XZ plane, and FIG. 6(b) shows the configuration when the state of FIG. 6(a) is compressed from both sides in the X-axis direction. That is, FIG. 6(a) shows the state before the plurality of power storage elements 200 and the plurality of spacers 300 are compressed (constrained) by the end plate 400 and the side plate 500, and FIG. 6(b) shows the state after the compression (constraint). In addition, in FIG. 6, the illustration of the components inside the container 210 of the power storage element 200 is omitted.

[0060] As shown in FIGS. 3 and 5, the spacer 310 is shorter in length than the container 210 of the power storage element 201 and the container 210 of the power storage element 202 in at least one direction of the Y-axis direction (second direction) and the Z-axis direction (third direction). In the present embodiment, the spacer 310 is shorter in length than the container 210 of the power storage element 201 and the container 210 of the power storage element 202 in both the Y-axis direction and the Z-axis direction. Specifically, the spacer 310 is shorter in length than the container 210 of the power storage element 201 and the container 210 of the power storage element 202 in all directions orthogonal to the X-axis direction (first direction).

[0061] As shown in FIG. 3 and FIG. 8 described later, the spacer 330 has the same size as the container 210 of the power storage element 200 (201, 202) when viewed in the X-axis direction. Therefore, the spacer 310 is shorter in length than the spacer 330 in at least one of the Y-axis direction (second direction) and the Z-axis direction (third direction). In the present embodiment, the spacer 310 is shorter in length than the spacer 330 in both the Y-axis direction and the Z-axis direction. Specifically, the spacer 310 is shorter in length than the spacer 330 in all directions orthogonal to the X-axis direction (first direction).

[0062] The spacer 310 is disposed at the center of the long side surface 213 of the container 210 of the power storage element 201 and at the center of the long side surface 213 of the container 210 of the power storage element 202. Specifically, the spacer 310 is disposed at a position corresponding to the electrode body of the power storage element 201 (or the power storage element 202) on the long side surface 213. In the present embodiment, as described above, the center of the electrode body is disposed in the Z-axis minus direction (the direction away from the electrode terminal 240) with respect to the center of the container 210 in the Z-axis direction. Therefore, the center of the spacer 310 is disposed at a position away from the electrode terminal 240 with respect to the center of the container 210. The center of the spacer 310 is the centroid of the surface of the spacer 310 facing the power storage element 201 (or the power storage element 202) (the surface facing in the X-axis direction). The center of the container 210 of the power storage element 201 (or the power storage element 202) is, as described above, the centroid of the surface of the container 210 facing in the X-axis direction, that is, the centroid of the surface (the long side surface 213 in the present embodiment) of the container 210 of the power storage element 201 (or the power storage element 202) facing the spacer 310.

[0063] Specifically, as shown in FIG. 5, the spacer 310 is disposed such that the distance A between the spacer 310 and the terminal arrangement surface 211 of the container 210 is larger than the distance B between the spacer 310 and the bottom surface 214 of the container 210 when viewed in the X-axis direction. In the Y-axis direction, since the center of the electrode body is disposed at the same position as the center of the container 210, the center of the spacer 310 is also disposed at the same position as the center of the container 210.

[0064] Note that the spacer 310 is preferably disposed within the region of the flat portion of the electrode body included in the power storage element 201 (or the power storage element 202) when viewed from the X-axis direction. For example, in the case where the electrode body is a laminated (stacked) type electrode body in which electrode plates are laminated, the spacer 310 is preferably formed in a size and shape that can be disposed within the region of the entire electrode body when viewed from the X-axis direction. In the case where the electrode body is a flat wound type electrode body in which electrode plates are wound to form a flat portion and a curved portion, the spacer 310 is preferably formed in a size and shape that can be disposed within the region of the flat portion of the electrode body when viewed from the X-axis direction.

[0065] As shown in FIG. 6, when the spacer 310 is sandwiched between the two power storage elements 200 (201 and 202) and compressed from both sides in the X-axis direction, the spacer 310 bites into the central portion of the long side surface 213 of the container 210 of the two power storage elements 200 (201 and 202). As a result, as shown in FIG. 6(b), the container 210 of the power storage element 201 and the container 210 of the power storage element 202 at the position where the spacer 310 is not disposed approach each other. Therefore, the distance between the container 210 of the power storage element 201 and the container 210 of the power storage element 202 at the position where the spacer 310 is not disposed becomes smaller than the thickness of the spacer 310. When the distance is not constant, the maximum value of the distance can be adopted. When the thickness is not constant, the maximum value of the thickness can be adopted. That is, the maximum value of the above distance between the containers 210 of the power storage element 201 and the power storage element 202 is smaller than the maximum value of the thickness of the spacer 310.

[0066] In other words, the distance between the containers 210 of the power storage elements 201 and 202 (the long side surfaces 213) at the positions where the spacer 310 is not disposed is smaller than the thickness of the spacer 310 in at least one direction (in this embodiment, both directions) in the Y-axis direction and the Z-axis direction of the spacer 310. More specifically, the distance between the containers 210 of the power storage elements 201 and 202 (the long side surfaces 213) at the portion that does not overlap with the spacer 310 when viewed from the X-axis direction is smaller than the distance between the containers 210 of the power storage elements 201 and 202 (the long side surfaces 213) at the portion that overlaps with the spacer 310 when viewed from the X-axis direction. That is, the distance between the containers 210 of the power storage elements 201 and 202 (the long side surfaces 213) is smaller than the thickness of the spacer 310 in all directions orthogonal to the X-axis direction of the spacer 310.

[0067] [3.2 Explanation of Spacers 320 to 340] Next, the configuration of the spacers 320 to 340 will be described in detail. FIG. 7 is a perspective view showing the configuration of the spacers 320 to 340 according to this embodiment. Specifically, FIG. 7 shows a set of spacers 320 to 340 disposed between two power storage elements 200 (two sets of power storage element groups). FIG. 8 is a front view showing the positional relationship among the power storage element 200, the spacers 320 to 340, and the side plate 500 according to this embodiment. Specifically, FIG. 8 shows the configuration when the spacers 320 to 340 and the side plate 500 are assembled to the power storage element 200 as viewed from the +X-axis direction. In FIG. 8, for convenience of explanation, the illustration of the spacer 330 in the +X-axis direction is omitted, and the side plate 500 shows a cross section cut along a plane parallel to the YZ plane.

[0068] As shown in these figures, the spacer 320 has a shape that is symmetric with respect to the XZ plane at the center position in the Y-axis direction (or a shape that is rotationally symmetric when rotated about an axis passing through the center position and parallel to the Z-axis direction). The spacer 320 has a pair of recesses 321, two through holes 322, two through holes 323, a through hole 324, and a through hole 325.

[0069] The recessed portion 321 is a rectangular recess that is recessed in the Y-axis direction and extends in the Z-axis direction, provided on the side surfaces on both sides of the spacer 320 in the Y-axis direction. The through-hole 322 is a circular through-hole that penetrates the spacer 320 in the X-axis direction, provided at a position closer to the plus direction of the Y-axis and the plus direction of the Z-axis from the center position of the spacer 320 and at a position closer to the minus direction of the Y-axis at the minus-end of the Z-axis of the spacer 320. The through-hole 322 is arranged at a position corresponding to the two protrusions 336 described later that the spacer 330 in the minus direction of the X-axis has. The through-hole 323 is a circular through-hole that penetrates the spacer 320 in the X-axis direction, provided at a position closer to the minus direction of the Y-axis and the plus direction of the Z-axis from the center position of the spacer 320 and at a position closer to the plus direction of the Y-axis at the minus-end of the Z-axis of the spacer 320. The through-hole 323 is arranged at a position corresponding to the two protrusions 336 that the spacer 330 in the plus direction of the X-axis has.

[0070] The through-hole 324 is a circular through-hole that penetrates the spacer 320 in the X-axis direction, provided at the minus-end of the Y-axis and the plus-end of the Z-axis of the spacer 320. The through-hole 324 is arranged at a position corresponding to the protrusion 337 described later that the spacer 330 in the minus direction of the X-axis has. The through-hole 325 is a circular through-hole that penetrates the spacer 320 in the X-axis direction, provided at the plus-end of the Y-axis and the plus-end of the Z-axis of the spacer 320. The through-hole 325 is arranged at a position corresponding to the protrusion 337 that the spacer 330 in the plus direction of the X-axis has.

[0071] The spacer 340 has a through-hole 341, two through-holes 342, and two through-holes 343. The through-hole 341 is a circular through-hole provided in the central portion of the spacer 340 and penetrating the spacer 340 in the X-axis direction. The through-hole 341 is disposed at a position corresponding to a convex portion 335 of the spacer 330 described later. The through-hole 342 is a circular through-hole provided at the Y-axis plus direction end and the Z-axis plus direction end of the spacer 340 and at the Y-axis minus direction end and the Z-axis minus direction end of the spacer 340 and penetrating the spacer 340 in the X-axis direction. The through-hole 342 is disposed at a position corresponding to two protrusions 336 of the spacer 330 in the minus X-axis direction. The through-hole 343 is a circular through-hole provided at the Y-axis minus direction end and the Z-axis plus direction end of the spacer 340 and at the Y-axis plus direction end and the Z-axis minus direction end of the spacer 340 and penetrating the spacer 340 in the X-axis direction. The through-hole 343 is disposed at a position corresponding to two protrusions 336 of the spacer 330 in the plus X-axis direction.

[0072] The two spacers 330 disposed on both sides of the spacer 320 in the X-axis direction have the same shape and are rotated 180° around the Z-axis with respect to each other. The spacer 330 has a spacer body 331, a pair of spacer side walls 332, a recess 333, a protruding portion 334, a convex portion 335, two protrusions 336, a protrusion 337, a protrusion 338, and a through-hole 339.

[0073] The spacer body 331 is a flat and rectangular portion constituting the body of the spacer 330 and is disposed parallel to the YZ plane. In the present embodiment, the spacer body 331 is disposed so as to cover substantially the entire long side surface 213 of the container 210. The spacer side wall 332 is a plate-like portion protruding in the X-axis direction from both ends in the Y-axis direction of the spacer body 331 and extending in the Z-axis direction. In the present embodiment, the spacer side wall 332 is disposed along the short side surface 212 of the container 210. The spacer side wall 332 has a shape in which the position corresponding to the recess 321 of the spacer 320 is recessed.

[0074] The recess 333 is disposed at the central portion of the spacer body 331 and is a rectangular recess in which the central portion is recessed in the X-axis direction. The recess 333 is disposed to face the spacer 320 (340). The protruding portion 334 is a rectangular portion formed on the surface of the spacer body 331 opposite to the recess 333, in which the central portion of the spacer body 331 protrudes in the X-axis direction. The protruding portion 334 protrudes toward the long side surface 213 of the container 210 and is disposed in a state of being in contact with the long side surface 213. Specifically, the protruding portion 334 is disposed at a position where the container 210 is sandwiched between the spacer 310 and in a position corresponding to the spacer 310 in the X-axis direction (the first direction), and compresses the container 210 with the spacer 310 (see FIG. 3). In order for the protruding portion 334 to uniformly compress the container 210 from both sides in the X-axis direction with the spacer 310, it is preferable that the protruding amount from the spacer body 331 in the X-axis direction is half of the thickness of the spacer 310.

[0075] The convex portion 335 is a columnar protrusion that protrudes from the central portion of the recess 333 toward the spacer 320 (340) and is flat in the protruding direction. The convex portion 335 is disposed at a position corresponding to the through hole 341 of the spacer 340 and is inserted into the through hole 341. The protrusion 336 is disposed around the convex portion 335 in the recess 333 and is a columnar protrusion that protrudes toward the spacer 320 (340) and is flat in the protruding direction. The protrusion 336 of the spacer 330 in the minus X-axis direction is disposed at positions corresponding to the through hole 342 of the spacer 340 and the through hole 322 of the spacer 320, and is inserted into the through hole 342 and the through hole 322. The protrusion 336 of the spacer 330 in the plus X-axis direction is disposed at positions corresponding to the through hole 343 of the spacer 340 and the through hole 323 of the spacer 320, and is inserted into the through hole 343 and the through hole 323.

[0076] The protrusion 337 is arranged at the Z-axis positive direction end of the spacer body 331, and is a flat columnar protrusion in the protruding direction that protrudes toward the spacer 320. The protrusion 337 of the spacer 330 in the X-axis negative direction is arranged at the position corresponding to the through hole 324 of the spacer 320 at the Y-axis negative direction end of the spacer body 331, and is inserted into the through hole 324. The protrusion 337 of the spacer 330 in the X-axis positive direction is arranged at the position corresponding to the through hole 325 of the spacer 320 at the Y-axis positive direction end of the spacer body 331, and is inserted into the through hole 325. The protrusion 338 and the through hole 339 are arranged side by side in the Y-axis direction at the central portion in the Y-axis direction and the Z-axis negative direction end of the spacer body 331. The protrusion 338 of one spacer 330 is arranged at the position corresponding to the through hole 339 of the other spacer 330, and is a columnar protrusion that protrudes toward the through hole 339. The through hole 339 is a circular through hole into which the protrusion 338 is inserted.

[0077] With the configuration as described above, the spacer 340 is arranged in the recess 333 of the spacer 330, and the spacers 320 to 340 are assembled. Then, the spacers 320 to 340 and the side plate 500 are assembled to the power storage element 200.

[0078] As a result, as shown in FIG. 8, the spacer 320 protrudes from the edge of the container 210 of the power storage element 200 (201, 204, etc.) in the Y-axis direction (second direction) as viewed from the X-axis direction (first direction), and is on the side different from the electrode terminal 240 of the power storage element 201. In the present embodiment, the spacer 320 protrudes from the edges on both sides of the container 210 in the Y-axis direction (second direction) as viewed from the X-axis direction (first direction), and is on the side different from the electrode terminal 240 (a surface different from the terminal arrangement surface 211). Specifically, the spacer 320 protrudes from both of the pair of short side surfaces 212 of the container 210 as viewed from the X-axis direction. In the present embodiment, at both ends in the Y-axis direction, the entire Y-axis direction end portion of the spacer 320 protrudes from the short side surface 212. Note that the spacer 320 may be configured such that a part of the Y-axis direction end portion (for example, the portion of the recess 321) does not protrude from the short side surface 212, but it is preferable that both ends in the Z-axis direction of the Y-axis direction end portion protrude from the short side surface 212.

[0079] In the Z-axis direction (third direction), the spacer 320 is shorter than the container 210 of the power storage element 200 (201, 204, etc.). The spacer 330 has the same size as the container 210 of the power storage element 200 (201, 204, etc.) in the Z-axis direction. Therefore, in the Z-axis direction (third direction), the spacer 330 is longer than the spacer 320. In the present embodiment, at both ends in the Z-axis direction, the spacer 320 is arranged at a position that does not protrude from the container 210 and the spacer 330.

[0080] Specifically, the spacer 320 is disposed closer to the +Z-axis direction with respect to the container 210 and the spacer 330. In other words, in the Z-axis direction, the center of the spacer 320 is disposed in the +Z-axis direction rather than the center of the container 210 (and the center of the spacer 330). As a result, in the Z-axis direction (the third direction), the center of the spacer 320 is closer to at least one of the electrode terminals 240 of the power storage element 200 (201, 204, etc.), the gas discharge valve 231, the joint portion 215 of the container 210, and the joint portion 130 of the exterior body 100 than the center of the container 210. In the present embodiment, in the Z-axis direction, the center of the spacer 320 is disposed closer to all of the electrode terminals 240, the gas discharge valve 231, the joint portion 215, and the joint portion 130 (see FIG. 1) than the center of the container 210 (and the center of the spacer 330).

[0081] The side plates 500 (501, 502) are disposed in the recess 321 of the spacer 320 (and the recess in the spacer side wall 332 of the spacer 330). For this reason, in the Z-axis direction (the third direction), the center of the side plate 500 is disposed in the same direction (+Z-axis direction) as the center of the spacer 320 with respect to the center of the container 210. That is, also for the side plate 500, in the Z-axis direction, the center thereof is closer to at least one (all in the present embodiment) of the electrode terminals 240, the gas discharge valve 231, the joint portion 215, and the joint portion 130 than the center of the container 210 (and the center of the spacer 330). Note that the width in the Y-axis direction of the exterior body main body 110 of the exterior body 100 at both ends in the Y-axis direction of the spacer 320 and at positions corresponding to the side plates 500 is larger than the width in the Y-axis direction of the end portion in the -Z-axis direction (see FIGS. 1 and 2).

[0082] [Description of Effects] As described above, according to the power storage device 10 according to the embodiment of the present invention, a spacer 320 (first spacer) is disposed between a plurality of power storage elements 200 (for example, power storage elements 201 and 204 (first power storage element and second power storage element)) arranged in the X-axis direction (first direction). The spacer 320 protrudes from an edge in the Y-axis direction (second direction) of the container 210 of the power storage element 200, which is different from the electrode terminal 240, when viewed from the X-axis direction, and is shorter than the container 210 in the Z-axis direction (third direction). In this way, by protruding the spacer 320 from the edge in the Y-axis direction of the container 210 of the power storage element 200, which is different from the electrode terminal 240, the power storage element 200 can be protected against an impact from the Y-axis direction on the power storage element 200. Further, by protruding the spacer 320 from the edge in the Y-axis direction of the container 210 of the power storage element 200, there is a problem that the spacer 320 becomes larger in size and heavier. In particular, in order to improve the strength of the spacer 320, when the thickness of the spacer 320 is increased or the spacer 320 is formed of metal, the spacer 320 becomes larger in size or heavier. Therefore, the spacer 320 is formed to be shorter than the container 210 of the power storage element 200 in the Z-axis direction. Thereby, an increase in the size or weight of the spacer 320 can be suppressed. Therefore, in the power storage device 10, while protecting the power storage element 200, an increase in size or weight can be suppressed.

[0083] In the power storage device 10, by the spacer 320 protruding from the edges on both sides in the Y-axis direction of the container 210 of the power storage element 200, the power storage element 200 can be effectively protected against an impact from the Y-axis direction on the power storage element 200.

[0084] In the storage element 200, a configuration for protecting the electrode terminal 240, the current collector, the gas discharge valve 231, or the joint 215 of the container 210 is preferable, and in the power storage device 10, a configuration for protecting the joint 130 of the exterior body 100 is preferable. For this reason, the spacer 320 is arranged such that its center is closer to at least one of the electrode terminal 240, the current collector, the gas discharge valve 231, the joint 215 of the container 210 of the storage element 200, and the joint 130 of the exterior body 100 of the power storage device 10 than the center of the container 210 of the storage element 200. Thereby, at least one of the storage element 200 and the exterior body 100 can be effectively protected.

[0085] When the power storage device 10 includes the side plate 500, the side plate 500 is also arranged such that its center is located in the same direction as the center of the spacer 320 with respect to the center of the container 210 of the storage element 200. Thereby, at least one of the electrode terminal 240, the current collector, the gas discharge valve 231, the joint 215 of the container 210 of the storage element 200, and the joint 130 of the exterior body 100 of the power storage device 10 can be effectively protected by the side plate 500.

[0086] Separate from the spacer 320 for the purpose of protecting the storage element 200, an insulating spacer 330 (second spacer) is arranged for the purpose of insulating the storage element 200. In the present embodiment, since the spacer 320 is formed of a conductive member such as metal, by arranging the spacer 330 between the storage element 200 (for example, the storage element 201) and the spacer 320, insulation between the storage element 200 and the spacer 320 can be achieved. Even when the spacer 320 is formed of an insulating member, if the spacer 320 is not configured to insulate between two storage elements 200 (for example, the storage elements 201 and 204), by arranging the spacer 330, insulation between the two storage elements 200 can be achieved. Thereby, in the power storage device 10, the storage element 200 can be protected.

[0087] By forming the insulating spacer 330 to be longer than the spacer 320, the insulation of the power storage element 200 can be improved. In the present embodiment, since the spacer 320 is formed of a conductive member such as metal, by forming the spacer 330 to be longer than the spacer 320, the insulation between the power storage element 200 (for example, the power storage element 201) and the spacer 320 can be improved. Even when the spacer 320 is formed of an insulating member, since the spacer 320 is shorter than the container 210 in the Z-axis direction, the spacer 320 may not be able to sufficiently insulate between the two power storage elements 200 (for example, the power storage elements 201 and 204). Therefore, by arranging the spacer 330 that is longer than the spacer 320, the insulation between the two power storage elements 200 can be improved. As a result, in the power storage device 10, the power storage element 200 can be protected.

[0088] In the power storage device 10, a spacer 310 is disposed between two power storage elements 200 (for example, power storage elements 201 and 202) that are arranged in the X-axis direction (first direction) and are connected in parallel. A spacer 330 is disposed between two power storage elements 200 (for example, power storage elements 201 and 204) that are connected in series. And the spacer 310 is shorter in length than the spacer 330 in at least one of the Y-axis direction (second direction) and the Z-axis direction (third direction). Here, when two power storage elements 200 are connected in parallel, the potentials of the two power storage elements 200 become equal, so there is little need to insulate between the two power storage elements 200. When two power storage elements 200 are connected in parallel, it is difficult to prevent the thermal chain of the two power storage elements 200, so there is also little need to insulate the heat between the two power storage elements 200. For this reason, there is little need to dispose a large spacer that covers the entire surface of the container 210 for the purpose of insulation or heat insulation between two power storage elements 200 connected in parallel. Therefore, between the two power storage elements 200, a spacer that compresses the power storage element 200 against vibration or impact to protect the power storage element 200 (suppress the movement of the power storage element 200 or the movement of the electrode body in the container 210 of the power storage element 200) may be disposed. For this reason, a spacer 310 that is shorter in length than the spacer 330 between two power storage elements 200 connected in series in at least one of the Y-axis direction and the Z-axis direction is disposed between two power storage elements 200 connected in parallel. Thereby, since the spacer 310 can be made small, miniaturization or weight reduction of the power storage device 10 can be achieved.

[0089] In the power storage device 10, by forming the spacer 310 to be shorter in length than the spacer 330 in all directions orthogonal to the X-axis direction, miniaturization of the power storage device 10 can be achieved in all directions, and weight reduction of the power storage device 10 can also be achieved.

[0090] Generally, in the container 210 of the energy storage element 200, since a current collector, a gasket, etc. are arranged on the side of the electrode terminal 240 of the electrode body, the electrode body is arranged at a position closer to the side opposite to the electrode terminal 240 in the Z-axis direction. For this reason, in the Z-axis direction, the spacer 310 is formed to be shorter in length than the container 210 of the energy storage element 200, and the center of the spacer 310 is arranged at a position farther from the electrode terminal 240 than the center of the container 210 of the energy storage element 200. Thereby, since the spacer 310 can compress a position close to the electrode body of the energy storage element 200, the movement of the electrode body in the container 210 of the energy storage element 200 can be further suppressed. Therefore, in the configuration for reducing the size or weight of the energy storage device 10, the energy storage element 200 can be effectively protected.

[0091] Since the spacer 330 has a protruding portion 334 protruding toward the energy storage element 200 at a position corresponding to the spacer 310, the spacer 310 and the protruding portion 334 can compress the energy storage element 200 from both sides in the X-axis direction. Thereby, the movement of the energy storage element 200 or the movement of the electrode body in the container 210 of the energy storage element 200 can be further suppressed. Therefore, in the configuration for reducing the size or weight of the energy storage device 10, the energy storage element 200 can be effectively protected.

[0092] Since the distance between the containers 210 of the two energy storage elements 200 (for example, the energy storage elements 201 and 202) at the position where the spacer 310 is not arranged is smaller than the thickness of the spacer 310, the two energy storage elements 200 can approach each other at the portion where the spacer 310 is not arranged. Therefore, since an increase in the width in the X-axis direction when the two energy storage elements 200 are assembled can be suppressed, the size of the energy storage device 10 can be reduced.

[0093] [Description of Modification 5] As described above, the energy storage device 10 according to the present embodiment has been described. However, the present invention is not limited to the above embodiment. The embodiments disclosed this time are illustrative in all respects and not restrictive, and the scope of the present invention includes all modifications within the meaning and scope equivalent to the claims.

[0094] For example, in the above embodiment, the spacer 320 protrudes from the edges on both sides in the Y-axis direction of the container 210 of the power storage element 200 (both short side surfaces 212) when viewed from the X-axis direction. However, it does not necessarily have to protrude from the edge on one side in the Y-axis direction of the container 210 (one short side surface 212). That is, the spacer 320 only needs to protrude from at least one edge in the Y-axis direction of the container 210 when viewed from the X-axis direction. Alternatively, the spacer 320 protrudes from the edge in the Z-axis direction of the container 210, which is on the side different from the electrode terminal 240 of the power storage element 200 (bottom surface 214) when viewed from the X-axis direction, and may be shorter than the container 210 of the power storage element 200 in the Y-axis direction. That is, in the above embodiment, the Y-axis direction is taken as an example of the second direction, but the Z-axis direction may also be the second direction.

[0095] In the above embodiment, the spacer 320 and the side plate 500 are arranged closer to the positive Z-axis direction with respect to the container 210 and the spacer 330 of the power storage element 200. However, they may be arranged at the central portion in the Z-axis direction or closer to the negative Z-axis direction.

[0096] In the above embodiment, the spacer 310 is shorter than the container 210 of the power storage element 200 in all directions orthogonal to the X-axis direction. However, it may be longer than the container 210 in any direction orthogonal to the X-axis direction. Alternatively, the spacer 310 may be longer than the container 210 of the power storage element 200 in all directions orthogonal to the X-axis direction.

[0097] In the above embodiment, the center of the spacer 310 is arranged at a position farther from the electrode terminal 240 than the center of the container 210 of the power storage element 200. However, in the Z-axis direction, it may be arranged at the same position as the center of the container 210 or at a position closer to the electrode terminal 240 than the center of the container 210.

[0098] In the above embodiment, the spacer 330 has a pair of spacer side walls 332, a recess 333, a protrusion 334, etc., but it may not have these, and its shape is not particularly limited. The arrangement position, number, size, shape, etc. of the convex portion 335, protrusions 336, 337, 338, and through hole 339 of the spacer 330 are also not particularly limited. The same applies to other spacers 300.

[0099] In the above embodiment, the distance between the containers 210 of the power storage element 200 at the position where the spacer 310 is not arranged is made smaller than the thickness of the spacer 310. However, depending on the degree of compression by the end plate 400 and the side plate 500, the distance between the containers 210 may be about the same as the thickness of the spacer 310. Or, due to the central portion of the container 210 bulging, the distance between the containers 210 may become larger than the thickness of the spacer 310.

[0100] In the above embodiment, it is assumed that all the spacers 310 have the above configuration, but any one of the spacers 310 may not have the above configuration. The same applies to other spacers 300.

[0101] Modes constructed by arbitrarily combining the components included in the above embodiment and its modification examples are also included in the scope of the present invention.

[0102] The present invention can be realized not only as such a power storage device, but also as a first spacer, or a combination of a first spacer (spacer 320) and a second spacer (spacer 330).

Industrial Applicability

[0103] The present invention can be applied to a power storage device including a power storage element such as a lithium ion secondary battery.

Explanation of Signs

[0104] 10 Power storage device 100 Exterior body 121 External terminal 130, 215 Joint 200, 201, 202, 203, 204 Energy storage element 210 Container 211 Terminal arrangement surface 212 Short side 213 Long side 214 Bottom surface 231 Gas discharge valve 240 Electrode terminal 300, 310, 320, 330, 340 Spacer 311 Joint member 321, 333 Recess 322, 323, 324, 325, 339, 341, 342, 343 Through hole 331 Spacer body 332 Spacer side wall 334 Protrusion 335 Convex part 336, 337, 338 Protrusion 400, 401, 402 End plate 500, 501, 502 Side plate 700 Bus bar

Claims

1. A power storage device including a first power storage element and a second power storage element arranged in a first direction, and a first spacer disposed between the first power storage element and the second power storage element, wherein: the first power storage element has an electrode terminal and a container in which the electrode terminal is disposed; the first spacer: projects from an edge of the container in a second direction orthogonal to the first direction as viewed from the first direction, the edge being on a side different from the electrode terminal, and is shorter in length than the container in a third direction orthogonal to the first direction and the second direction; in the third direction, the center of the first spacer is disposed at a position closer to at least one of the electrode terminal of the first power storage element, a gas discharge valve, a joint of the container, and a joint of an exterior body in which the first power storage element and the first spacer are accommodated, than the center of the container; the power storage device further includes a side plate disposed in the second direction of the first power storage element, the second power storage element, and the first spacer; in the third direction, the center of the side plate is disposed in the same direction as the center of the first spacer with respect to the center of the container; a power storage device.

2. A power storage device including a first power storage element and a second power storage element arranged in a first direction, and a first spacer disposed between the first power storage element and the second power storage element, wherein: the first power storage element has an electrode terminal and a container in which the electrode terminal is disposed; the first spacer: projects from an edge of the container in a second direction orthogonal to the first direction as viewed from the first direction, the edge being on a side different from the electrode terminal, and is shorter in length than the container in a third direction orthogonal to the first direction and the second direction; at an edge in the second direction, an end portion of the first spacer in the third direction protrudes more in the second direction than other portions; a power storage device.

3. A power storage device including a first power storage element and a second power storage element arranged in a first direction, and a first spacer disposed between the first power storage element and the second power storage element, wherein: the first power storage element has an electrode terminal and a container in which the electrode terminal is disposed; the first spacer: projects from an edge of the container in a second direction orthogonal to the first direction as viewed from the first direction, the edge being on a side different from the electrode terminal, and is shorter in length than the container in a third direction orthogonal to the first direction and the second direction; When viewed from the first direction, the first spacer protrudes in the second direction from the joint portion of the container. Power storage device. **Claim 4** A power storage device comprising a first power storage element and a second power storage element arranged in a first direction, and a first spacer disposed between the first power storage element and the second power storage element, The first power storage element has an electrode terminal and a container in which the electrode terminal is disposed. The first spacer When viewed from the first direction, it protrudes from an edge of the container in a second direction orthogonal to the first direction and on a side different from the electrode terminal, and in a third direction orthogonal to the first direction and the second direction, its length is shorter than that of the container. The first spacer is a flat plate-like member whose end in the second direction does not protrude in the first direction. Power storage device. **Claim 5** When viewed from the first direction, the first spacer protrudes from edges on both sides of the container in the second direction and on a side different from the electrode terminal. The power storage device according to any one of claims 1 to 4. **Claim 6** Furthermore, an insulating second spacer is provided between the first power storage element and the first spacer. The power storage device according to any one of claims 1 to 5. **Claim 7** In the third direction, the second spacer is longer than the first spacer. The power storage device according to claim 6.

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