Electricity storage device

Abstract

A power storage device is provided with a plurality of power storage elements, and a spacer disposed between the plurality of power storage elements in a first direction, the spacer having a spacer main body, a first protrusion protruding from the spacer main body toward one side in the first direction, and a second protrusion protruding from the spacer main body toward the other side in the first direction. The first protruding portion and the second protruding portion are disposed at different positions in at least one of a second direction and a third direction, which are two directions orthogonal to the first direction and orthogonal to each other.

Description

TECHNICAL FIELD

[0001] The present application relates to an electricity storage device. BACKGROUND

[0002] In the past, an electricity storage device provided with a plurality of electricity storage elements and a spacer disposed between the plurality of electricity storage elements has been widely known. A battery pack in which a spacer is disposed between a plurality of single cells and a plurality of convex portions protruding to both sides of the single cells are provided on both surfaces of the spacer is disclosed in Patent Literature 1.

[0003] PRIOR ART LITERATURE

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2019-96431 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] In the electricity storage device, if the deviation of the size of the electricity storage element is large, there is a problem that the deviation of the pressing force of the electricity storage element caused by the spacer becomes large. If the size of the electricity storage element becomes large, it is likely that the pressing force caused by the spacer becomes too large, or if the size of the electricity storage element becomes small, it is likely that the pressing by the spacer is not sufficient. In the existing electricity storage device disclosed in the above Patent Literature 1, a plurality of convex portions are provided on both surfaces of the spacer, but if the deviation of the size of the electricity storage element is large, the deviation of the pressing force of the electricity storage element caused by the convex portions of the spacer becomes large.

[0008] The present application is achieved by the present inventors newly focusing on the above problem, and aims to provide an electricity storage device that can absorb the deviation of the size of the electricity storage element.

[0009] MEANS FOR SOLVING THE PROBLEMS

[0010] The electricity storage device according to an aspect of the present application includes a plurality of electricity storage elements, and a spacer disposed between the plurality of electricity storage elements in a first direction, the spacer including a spacer main body, a first protruding portion protruding from the spacer main body toward one side of the first direction, and a second protruding portion protruding from the spacer main body toward the other side of the first direction, the first protruding portion and the second protruding portion being disposed at different positions in at least one of a second direction and a third direction that are orthogonal to the first direction and to each other.

[0011] EFFECT OF THE INVENTION

[0012] According to the electricity storage device of the present application, the deviation of the size of the electricity storage element can be absorbed. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a perspective view showing the appearance of the power storage device according to the embodiment.

[0014] Figure 2 is an exploded perspective view showing the case where the power storage device according to the embodiment is disassembled.

[0015] Figure 3 is a perspective view showing the structure of the power storage element according to the embodiment.

[0016] Figure 4 is a perspective view showing the structure of the spacer according to the embodiment.

[0017] Figure 5 is a perspective view showing the structure of the spacer according to the embodiment.

[0018] Figure 6 is a front view and a back view showing the structure of the spacer according to the embodiment.

[0019] Figure 7 is a front view and a back view showing the structure of the spacer according to the modification of the embodiment.

[0020] Figure 8 is a front view and a back view showing the structure of the spacer according to the modification of the embodiment. DETAILED DESCRIPTION

[0021] (1) The power storage device according to an embodiment of the present application includes a plurality of power storage elements and a spacer disposed between the plurality of power storage elements in a first direction, the spacer including a spacer main body, a first protrusion protruding from the spacer main body toward one side of the first direction, and a second protrusion protruding from the spacer main body toward the other side of the first direction, the first protrusion and the second protrusion being disposed at different positions in at least one of a second direction and a third direction orthogonal to the first direction.

[0022] According to the power storage device according to an embodiment of the present application, the spacer includes a first protrusion and a second protrusion protruding from a spacer main body toward one side and the other side of a first direction, the first protrusion and the second protrusion being disposed at different positions in at least one of a second direction and a third direction. In this way, by disposing the first protrusion and the second protrusion of the spacer at different positions in at least one of the second direction and the third direction, the first protrusion and the second protrusion are easily deformed in the first direction from each other. Thus, the spacer can absorb the dimensional deviation of the power storage elements.

[0023] (2) In the power storage device described in (1) above, the spacer can have a plurality of the first protrusions, the plurality of the first protrusions can have: a long protrusion extending in the second direction; and a short protrusion disposed in the second direction from the long protrusion as viewed in the third direction, the second direction being shorter than the long protrusion.

[0024] The power storage device described in (2) above, the plurality of the first protrusions of the spacer can have: a long protrusion long in the second direction; and a short protrusion disposed in the second direction from the long protrusion as viewed in the third direction, the second direction being shorter than the long protrusion. Thus, by disposing the protrusions (the long protrusion and the short protrusion) of different lengths in the second direction in the spacer, even if the size deviation of the power storage elements in the second direction is complicated, the protrusion of a length corresponding to the size deviation of the power storage elements can be disposed.

[0025] (3) In the power storage device described in (2) above, the plurality of the first protrusions can have two short protrusions, the long protrusion being disposed between the two short protrusions as viewed in the third direction.

[0026] The power storage device described in (3) above, the size deviation of the power storage elements is greater in the central portion than in the end portions of the power storage elements. Therefore, the smaller size deviation of the power storage elements can be absorbed by the short protrusion of the spacer, and the greater size deviation of the power storage elements can be absorbed by the long protrusion of the spacer. Since the power storage elements are more bulged in the central portion than in the end portions, the bulging of the power storage elements can be suppressed by the long protrusion of the spacer.

[0027] (4) In the power storage device described in (2) or (3) above, the protruding length of the long protrusion and the short protrusion from the main body of the spacer can be different.

[0028] The power storage device described in (4) above, by making the protruding lengths of the long protrusion and the short protrusion of the spacer different, even if the size deviation of the power storage elements is complicated, the protrusion of a protruding length corresponding to the size deviation of the power storage elements can be disposed.

[0029] (5) In any one of the power storage devices described in (2) to (4) above, the plurality of the power storage elements can each have a container, and a center position of the long protrusion can be disposed at a position different from a center position of the container in the second direction.

[0030] The power storage device according to (5) above, in a case where bias occurs in the second direction in the deviation of the size of the power storage element, the center position of the long protruding portion of the spacer is disposed at a position different from the center position of the container of the power storage element. Thus, the bias in the second direction in the deviation of the size of the power storage element can be suppressed. Even in a case where bias occurs in the second direction in the bulging of the power storage element, the bulging of the power storage element can be more evenly suppressed by the long protruding portion.

[0031] (6) In any one of the power storage devices according to (1) to (5) above, the plurality of power storage elements can each have a container formed with a joint portion joining two portions, and at least one of the first protruding portion and the second protruding portion can extend toward the joint portion.

[0032] The power storage device according to (6) above, by the protruding portion (at least one of the first protruding portion and the second protruding portion) of the spacer extending toward the joint portion of the container of the power storage element, the protruding portion becomes disposed in the vicinity of the joint portion. Thus, even in a case where the container of the power storage element bulges, the vicinity of the joint portion of the container can be suppressed from bulging by the protruding portion, and thus damage to the joint portion can be suppressed.

[0033] (7) In any one of the power storage devices according to (1) to (6) above, the spacer can have two second protruding portions, and in at least one of the second direction and the third direction, the first protruding portion can be disposed between the two second protruding portions.

[0034] The power storage device according to (7) above, in the spacer, by the first protruding portion being disposed between the two second protruding portions, the first protruding portion is deformed in the first direction between the two second protruding portions. Thus, the first protruding portion can be more stably deformed.

[0035] Hereinafter, a power storage device according to an embodiment (including modifications thereof) of the present application will be described with reference to the drawings. Each of the embodiments described below indicates a general or specific example. The numerical values, shapes, materials, structural elements, disposition positions of structural elements, connection methods, manufacturing processes, order of manufacturing processes, and the like shown in the following embodiments are examples, and are not intended to limit the gist of the present application. In each of the drawings, the dimensions and the like are not strictly illustrated. In each of the drawings, the same reference numerals are assigned to the same or similar structural elements.

[0036] In the following description and drawings, the direction of arrangement of a pair of terminals of the electricity storage element, or the direction of facing of a pair of short sides in the container of the electricity storage element is defined as the X-axis direction. The direction of facing of a pair of long sides in the container of the electricity storage element, the thickness direction (flat direction) of the electricity storage element or the spacer, or the direction of arrangement of the electricity storage element and the spacer is defined as the Y-axis direction. The direction of protrusion of the terminal of the electricity storage element, the direction of arrangement of the container main body portion and the container lid portion of the electricity storage element, the direction of arrangement of the case main body and the lid portion of the case, the direction of facing of the opening and the bottom wall of the case main body, or the up-down direction is defined as the Z-axis direction. These X-axis direction, Y-axis direction, and Z-axis direction are directions that cross each other (in this embodiment, orthogonal directions). Although the Z-axis direction is not necessarily the up-down direction depending on the usage, the Z-axis direction is described as the up-down direction for convenience of explanation.

[0037] In the following description, the X-axis positive direction indicates the arrow direction of the X-axis, and the X-axis negative direction indicates the opposite direction of the X-axis positive direction. In the case of simply referring to the X-axis direction, the direction of either or both of the X-axis positive direction and the X-axis negative direction is indicated. The same applies to the Y-axis direction and the Z-axis direction. Hereinafter, the Y-axis direction is also referred to as the first direction, the Z-axis direction is also referred to as the second direction, and the X-axis direction is also referred to as the third direction. The expressions of parallel and orthogonal and the like indicating relative directions or attitudes also include cases where the directions or attitudes are not strictly parallel or orthogonal. By the two directions being parallel, it is meant not only that the two directions are completely parallel, but also that the two directions are substantially parallel, that is, a difference of several percent or less is included. In the following description, in the case of being expressed as "insulation", it means "electrical insulation".

[0038] (Embodiment)

[0039] [1 Explanation of electricity storage device 1]

[0040] First, the outline structure of the electricity storage device 1 in this embodiment is described. Figure 1 is a perspective view showing the appearance of the electricity storage device 1 to which this embodiment is applied. Figure 2 is an exploded perspective view showing each structural element in the case where the electricity storage device 1 to which this embodiment is applied is disassembled.

[0041] The energy storage device 1 is a device capable of charging electricity from an external source and discharging electricity to an external source. In this embodiment, it has a generally cuboid shape. Here, a cuboid refers to a hexahedron whose faces are all composed of rectangles or squares. The energy storage device 1 is a battery module (battery pack) used for electricity storage or power supply purposes. The energy storage device 1 is used as a battery for driving or starting engines of moving vehicles such as automobiles, motorized two-wheelers, watercraft, ships, snowmobiles, agricultural machinery, construction machinery, or railway vehicles for electric railways. Examples of automobiles include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fossil fuel (gasoline, light oil, liquefied natural gas, etc.) automobiles. Examples of railway vehicles for electric railways include trams, monorail trains, linear motor vehicles, and hybrid trams equipped with both diesel and electric motors. The energy storage device 1 can also be used as a battery for stationary installations in homes or commercial applications.

[0042] like Figure 1 As shown, the energy storage device 1 includes a housing 10. Figure 2 As shown, the housing 10 houses multiple energy storage elements 300, multiple spacers 400 (400a to 400d), and multiple busbars 600 (601 to 603). The energy storage device 1 also includes external terminals (positive and negative external terminals) for electrical connection to external devices, but these are omitted from illustration and description. In addition to the structural elements described above, the energy storage device 1 may also include restraining members (end plates, side plates, etc.) for securing the multiple energy storage elements 300, busbar holding members for holding the busbars 600, busbar covers, and exhaust sections for venting gas discharged from the energy storage elements 300 to the outside of the housing 10. The energy storage device 1 may also include electrical components such as circuit boards, relays, fuses, bypass resistors, and connectors for monitoring or controlling the charging and discharging states of the energy storage elements 300.

[0043] The housing 10 is a generally rectangular (box-shaped) container (module housing) constituting the outer casing (housing, outer shell) of the energy storage device 1. The housing 10 is disposed outside a plurality of energy storage elements 300 and a plurality of spacers 400, fixing the plurality of energy storage elements 300 and spacers 400 in a given position and protecting them from impacts, etc. The housing 10 is a metal housing formed from metal components such as aluminum, aluminum alloy, stainless steel, iron, or plated steel sheet. In this embodiment, the housing 10 is formed by aluminum casting, specifically die casting (aluminum die casting). The housing 10 may also be formed from any insulating component such as resin material that can be used in the spacers 400 described later.

[0044] like Figure 1As shown, the case 10 has: a case main body 100 that constitutes a main body of the case 10; and a cover 200 that constitutes a cover of the case 10. The case main body 100 is a bottomed rectangular cylindrical housing (chassis) having an opening 101 formed in the positive direction of the Z axis, and houses a plurality of power storage elements 300, a plurality of spacers 400, and the like. Specifically, the case main body 100 has a bottom wall 110 that is flat and rectangular in shape in the negative direction of the Z axis, a pair of side walls 120 that are flat and rectangular in shape on both sides in the Y axis direction, and a pair of side walls 130 that are flat and rectangular in shape on both sides in the X axis direction. Depending on the structure of the contents of the case main body 100 and the like, the bottom wall 110, the side walls 120, and the side walls 130 can be any shape, the side walls 120 can be short side walls, and the side walls 130 can be long side walls. The cover 200 is a flat rectangular member that plugs the rectangular opening 101 of the case main body 100. The case main body 100 and the cover 200 are joined by screw fastening based on bolts or the like. Thus, the case 10 becomes a configuration in which the inside is sealed. The case main body 100 and the cover 200 can be joined by welding or adhesion or the like. The case main body 100 and the cover 200 can be formed of members of the same material, or can be formed of members of different materials.

[0045] The power storage element 300 is a secondary battery (single cell) that can be charged with electricity and can discharge electricity, and more specifically, a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery. The power storage element 300 has a shape in which the length in the X axis direction is longer than the length in the Y axis direction, and specifically, has a flat rectangular parallelepiped shape (square, cuboid) in the Y axis direction. In the present embodiment, eight power storage elements 300 are arranged in the X axis direction and the Y axis direction. Specifically, two (two groups) of power storage element rows each composed of four power storage elements 300 arranged in the Y axis direction are arranged in the X axis direction. The size, shape, and number of arranged power storage elements 300 of the power storage element 300 are not particularly limited, and can be a long cylindrical shape, an elliptical cylindrical shape, a polyhedral shape other than a rectangular parallelepiped, or the like. The power storage element 300 is not limited to a nonaqueous electrolyte secondary battery, and can be a secondary battery other than a nonaqueous electrolyte secondary battery, or can be a capacitor. The power storage element 300 can not be a secondary battery, but can be a primary battery in which a user can use the stored electricity even without charging. The power storage element 300 can be a battery using a solid electrolyte. The power storage element 300 can be a pouch-type power storage element. Detailed description of the structure of the power storage element 300 is described later.

[0046] The spacer 400 is arranged in the Y-axis direction in parallel with the power storage elements 300, and is a member that is flat in the Y-axis direction (flat when viewed in the X-axis direction and the Z-axis direction) and insulates and / or thermally insulates the power storage elements 300 and other members. The spacer 400 is arranged adjacent to the power storage elements 300 in the positive Y-axis direction or the negative Y-axis direction of the power storage elements 300, and is an insulating plate or a thermal insulating plate that insulates and / or thermally insulates the power storage elements 300 from each other or the power storage elements 300 and the case 10. The spacer 400 is formed of 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), polyamide (PA), ABS resin, or a composite material of these materials, or a member having thermal insulation such as mica, or the like. The spacer 400 has a function of a retainer that retains the power storage elements 300 to position the power storage elements 300, by having a wall portion on both sides in the X-axis direction and both sides in the Z-axis direction of the power storage elements 300.

[0047] Hereinafter, among the five spacers 400 in the positive X-axis direction, the spacer 400 arranged between a plurality (two) of the power storage elements 300 in the Y-axis direction (first direction) will be referred to as a spacer 400a. Among the five spacers 400 in the positive X-axis direction, the spacer 400 arranged at both end portions in the Y-axis direction (between the end portion power storage elements 300 and the side wall 120 of the case 10) will be referred to as a spacer 400b. In the present embodiment, three spacers 400a and two spacers 400b are arranged alternately with the four power storage elements 300, but the arrangement positions and the number of the spacers 400a and 400b are not particularly limited. Among the five spacers 400 in the negative X-axis direction, the spacer 400 arranged between a plurality (two) of the power storage elements 300 in the Y-axis direction (first direction) will be referred to as a spacer 400c. Among the five spacers 400 in the negative X-axis direction, the spacer 400 arranged at both end portions in the Y-axis direction (between the end portion power storage elements 300 and the side wall 120 of the case 10) will be referred to as a spacer 400d. In the present embodiment, three spacers 400c and two spacers 400d are arranged alternately with the four power storage elements 300, but the arrangement positions and the number of the spacers 400c and 400d are not particularly limited.

[0048] Specifically, the spacer 400a has wall portions on both sides in the X-axis direction and on both sides in the Z-axis direction of the two power storage elements 300 arranged on both sides in the Y-axis direction of the spacer 400a, and is an intermediate spacer (intermediate holder) that holds the two power storage elements 300. The same applies to the spacer 400c. The spacer 400b has wall portions on both sides in the X-axis direction and on both sides in the Z-axis direction of the one power storage element 300 arranged on one side in the Y-axis direction of the spacer 400b, and is a terminal spacer (terminal holder) that holds the one power storage element 300. The same applies to the spacer 400d. That is, the power storage elements 300 located at the end portions in the Y-axis direction among the four power storage elements 300 in the positive direction of the X-axis are held by the spacer 400a and the spacer 400b, and the power storage elements 300 other than these are held by the two spacers 400a. The power storage elements 300 located at the end portions in the Y-axis direction among the four power storage elements 300 in the negative direction of the X-axis are held by the spacer 400c and the spacer 400d, and the power storage elements 300 other than these are held by the two spacers 400c. The entire spacers 400 (400a to 400d) can be formed of members of the same material, or any of the spacers 400 can be formed of members of different materials. Detailed description of the structure of the spacers 400 will be given later.

[0049] The bus bars 600 are plate-shaped members that are connected to the power storage elements 300. The bus bars 600 are arranged above the plurality of power storage elements 300 and connected (joined) to the terminals 340 possessed by the plurality of power storage elements 300. Specifically, the bus bars 600 connect the terminals 340 of the plurality of power storage elements 300 to each other, and electrically connect the terminals 340 of the power storage elements 300 at the ends and external terminals (not shown). In the present embodiment, five bus bars 600 connect two power storage elements 300 in parallel to constitute four sets of power storage element groups, and connect the four sets of power storage element groups in series. Specifically, the bus bar 601 in the positive direction of the X-axis among the five bus bars 600 connects two sets of power storage element groups in the positive direction of the X-axis in series, and the bus bar 601 in the negative direction of the X-axis connects two sets of power storage element groups in the negative direction of the X-axis in series. The bus bar 602 in the central portion in the X-axis direction and in the negative direction of the Y-axis connects two sets of power storage element groups in the negative direction of the Y-axis in series. The two bus bars 603 in the central portion in the X-axis direction and in the positive direction of the Y-axis connect two sets of power storage element groups in the positive direction of the Y-axis and a pair (positive and negative) of external terminals (not shown) via other bus bars or the like, respectively.

[0050] The connection method of the bus bar 600 is not particularly limited, and a plurality of the power storage elements 300 can be connected in series or in parallel in any combination, or all of the power storage elements 300 can be connected in series or in parallel. The bus bar 600 and the terminal 340 are connected (joined) by welding or the like, but the connection method is not particularly limited. The bus bar 600 can be formed of a conductive member made of a metal such as aluminum, an aluminum alloy, copper, a copper alloy, nickel, or the like, or a combination thereof, or a conductive member other than a metal, or the like.

[0051] [2 Description of Power Storage Element 300]

[0052] Next, the structure of the power storage element 300 will be described in detail. Figure 3 is a perspective view showing the structure of the power storage element 300 according to the present embodiment. Figure 3 The power storage element 300 shown in Figure 2 is shown enlarged. The plurality of power storage elements 300 provided in the power storage device 1 all have the same structure, and therefore, in Figure 3 , one power storage element 300 is shown, and the structure of one power storage element 300 will be described in detail below.

[0053] As shown in Figure 3 , the power storage element 300 has a container 310, a pair of (positive and negative) terminals 340, and a pair of (positive and negative) gaskets 350. Inside the container 310, an electrode body, a pair of (positive and negative) current collectors, and an electrolyte (non-aqueous electrolyte), and the like are housed, but the illustration of these is omitted. As the electrolyte, as long as the performance of the power storage element 300 is not impaired, the kind is not particularly limited, and various electrolytes can be selected. The power storage element 300 can have, in addition to the above-described structural elements, a spacer disposed to the side or the lower side of the electrode body, an insulating film that encloses the electrode body and the like, or an insulating film (shrinkable tube or the like) that covers the outer surface of the container 310, and the like.

[0054] The container 310 is a rectangular parallelepiped-shaped case having a container main body portion 320 formed with an opening, and a container lid portion 330 that closes the opening of the container main body portion 320. The container main body portion 320 is a rectangular cylindrical member constituting the main body portion of the container 310, and has a bottom, and is formed with an opening on the positive direction side of the Z axis. The container lid portion 330 is a rectangular plate-shaped member constituting the lid portion of the container 310, and is disposed on the positive direction side of the Z axis of the container main body portion 320. A gas discharge valve 331 that releases the pressure inside the container 310 in the case of excessive increase in the pressure, and a liquid injection portion (not shown) for injecting an electrolyte into the inside of the container 310, and the like are provided in the container lid portion 330. The material of the container 310 (the container main body portion 320 and the container lid portion 330) is not particularly limited, and can be a metal such as stainless steel, aluminum, aluminum alloy, iron, plated steel sheet, or the like that can be welded (joined), but a resin can also be used.

[0055] The container 310 is configured such that, after the electrode body or the like is housed in the inside of the container main body portion 320, the container main body portion 320 and the container lid portion 330 are joined by welding or the like to form a joining portion 310a, thereby sealing the inside. The joining portion 310a is formed in the container 310, and is a joining portion in which two portions (the container main body portion 320 and the container lid portion 330) are joined. In the present embodiment, the container main body portion 320 and the container lid portion 330 are joined by laser welding by irradiating laser light from the side (the X axis direction and the Y axis direction) of the container 310, thereby forming the joining portion 310a. The joining portion 310a is a quadrilateral ring-shaped joining portion that surrounds the periphery (the entire periphery) of the container 310 at the Z axis positive direction end portion of the container 310.

[0056] The container 310 has a pair of long sides 311 on the side surfaces on both sides in the Y axis direction, a pair of short sides 312 on the side surfaces on both sides in the X axis direction, and a bottom surface 313 on the negative direction side of the Z axis. The long side 311 is a rectangular planar portion that forms a long side of the container 310, and is disposed in opposition to the adjacent partition 400 in the Y axis direction. The long side 311 is adjacent to the short side 312 and the bottom surface 313, and has a larger area than the short side 312. The short side 312 is a rectangular planar portion that forms a short side of the container 310, and is disposed in opposition to the wall portion of the partition 400 and the side wall 130 of the case 10 in the X axis direction. The short side 312 is adjacent to the long side 311 and the bottom surface 313, and has a smaller area than the long side 311. The bottom surface 313 is a rectangular planar portion that forms a bottom surface of the container 310, and is disposed in opposition to the wall portion of the partition 400 and the bottom wall 110 of the case 10 in the Z axis direction. The bottom surface 313 is disposed in opposition to the long side 311 and the short side 312.

[0057] The terminal 340 is disposed in the container lid portion 330 and is an electrode terminal (positive electrode terminal and negative electrode terminal) of the power storage element 300. Specifically, the terminal 340 is disposed in a state of protruding in the positive direction of the Z axis from the upper surface (terminal disposition surface) of the container lid portion 330. The terminal 340 is electrically connected to the positive electrode plate and the negative electrode plate of the electrode body via the current collector. That is, the terminal 340 is a metal member for leading electricity accumulated in the electrode body to the outside of the power storage element 300 and leading electricity to the inside of the power storage element 300 in order to accumulate electricity in the electrode body. The terminal 340 is formed of aluminum, aluminum alloy, copper, copper alloy, or the like.

[0058] The electrode body is a power storage element (power generation element) in which a positive electrode plate, a negative electrode plate, and a separator are stacked. The positive electrode plate is obtained by forming a positive electrode active material layer on a current collecting foil containing a metal such as aluminum or aluminum alloy. The negative electrode plate is obtained by forming a negative electrode active material layer on a current collecting foil containing a metal such as copper or copper alloy. As the active material used in the positive electrode active material layer and the negative electrode active material layer, a publicly known material can be appropriately used as long as it is an active material capable of occluding and releasing a charge transport ion. The separator can use a microporous sheet or nonwoven fabric containing a resin or the like. In the present embodiment, the electrode body is formed by stacking the electrode plates (positive electrode plate and negative electrode plate) in the Y axis direction. The electrode body can be a jelly-roll type electrode body formed by winding the electrode plates (positive electrode plate and negative electrode plate), a stacked type (stacked type) electrode body formed by stacking a plurality of flat electrode plates, a snakelike type electrode body formed by folding the electrode plates in a snakelike manner, or the like, and can be any type of electrode body.

[0059] The current collector is an electrically conductive current collecting member (positive electrode current collector and negative electrode current collector) electrically connected to the terminal 340 and the electrode body. The positive electrode current collector contains aluminum or aluminum alloy or the like similarly to the current collecting foil of the positive electrode plate of the electrode body, and the negative electrode current collector contains copper or copper alloy or the like similarly to the current collecting foil of the negative electrode plate of the electrode body. The gasket 350 is disposed between the container lid portion 330 and the terminal 340 and the current collector and is a gasket for insulating the container lid portion 330 from the terminal 340 and the current collector. The gasket 350 can be formed of any material as long as it has insulating properties.

[0060] [3 Explanation of the spacer 400]

[0061] Next, the structure of the spacer 400 will be described in detail. The spacer 400b among the spacers 400 has the same structure as the half of the spacer 400a in the Y-axis direction (a portion formed by cutting the spacer 400a with a plane passing through the center position of the spacer 400a and parallel to the XZ plane). The spacer 400c has a shape symmetrical to the spacer 400a in the X-axis direction (symmetrical with respect to a plane parallel to the YZ plane) or a shape rotating the spacer 400a 180° with the Z-axis as the center. The spacer 400d has the same structure as the half of the spacer 400c in the Y-axis direction (a portion formed by cutting the spacer 400c with a plane passing through the center position of the spacer 400c and parallel to the XZ plane). Therefore, hereinafter, the structure of the spacer 400a will be described in detail, and the description of the structures of the spacers 400b, 400c, and 400d will be simplified or omitted.

[0062] Figure 4 and Figure 5 is a perspective view showing the structure of the spacer 400a according to the present embodiment. Specifically, Figure 4 is an enlarged view showing Figure 2 the perspective view of the spacer 400a shown in Figure 5 is a perspective view showing the structure of the spacer 400a according to the present embodiment. Specifically, Figure 4 is a perspective view showing the structure of the spacer 400a according to the present embodiment. Specifically, Figure 4 represents a surface of the spacer 400a in the negative direction of the Y-axis, Figure 5 represents a surface of the spacer 400a in the positive direction of the Y-axis Figure 4 the back surface of the spacer 400a of Figure 6 is a front view and a back view showing the structure of the spacer 400a according to the present embodiment. Specifically, Figure 6 (a) of Figure 4 is a front view showing the structure of the spacer 400a according to the present embodiment as viewed from the negative direction of the Y-axis, Figure 6 (b) of Figure 5 is a back view showing the structure of the spacer 400a according to the present embodiment as viewed from the positive direction of the Y-axis.

[0063] As shown in Figure 4 to Figure 6As shown, the spacer 400a has a spacer main body 410 and spacer wall portions 420 to 440 arranged on both sides in the Z-axis direction and both sides in the X-axis direction of the electricity storage element 300. The spacer main body 410 is a flat and rectangular portion that constitutes a main portion of the spacer 400a and is arranged in parallel with the XZ plane. In the present embodiment, the spacer main body 410 is arranged in the positive direction of the Y-axis or the negative direction of the Y-axis of the electricity storage element 300. As viewed in the Y-axis direction, the spacer main body 410 is formed in substantially the same shape and size as the container 310 of the electricity storage element 300 and is arranged at substantially the same position as the container 310 of the electricity storage element 300. Thus, the spacer main body 410 is arranged in opposition to the long side surface 311 of the container 310 of the electricity storage element 300 in the Y-axis direction so as to cover the entire surface of the long side surface 311.

[0064] The spacer wall portion 420 is a flat portion that protrudes from the Z-axis positive direction end portion of the spacer main body 410 to both sides in the Y-axis direction and is arranged in parallel with the XY plane. The spacer wall portion 420 is arranged in the Z-axis positive direction of the container lid portion 330 of the electricity storage element 300. The spacer wall portion 420 is arranged in opposition to the container lid portion 330 in the Z-axis direction. In the present embodiment, the spacer wall portion 420 is arranged separately from the container lid portion 330, but can be arranged in contact with the container lid portion 330.

[0065] The spacer wall portion 430 is a flat portion that protrudes from the Z-axis negative direction end portion of the spacer main body 410 to both sides in the Y-axis direction and is arranged in parallel with the XY plane. The spacer wall portion 430 is a long portion that extends in the X-axis direction from one end to the other end of the spacer main body 410 in the X-axis direction. The spacer wall portion 430 is arranged in opposition to the bottom surface 313 of the container 310 of the electricity storage element 300 and the bottom wall 110 of the case main body 100 of the case 10 in the Z-axis direction between the bottom surface 313 and the bottom wall 110. In the present embodiment, the spacer wall portion 430 is arranged in contact with the bottom surface 313 and the bottom wall 110.

[0066] The spacer wall portion 440 is a flat plate-shaped portion protruding from both end portions of the spacer main body 410 in the X-axis direction to both sides in the Y-axis direction, and is arranged in parallel to the YZ plane. The spacer wall portion 440 is a long strip-shaped portion extending in the Z-axis direction from one end of the spacer main body 410 to the other end. The spacer wall portion 440 is arranged in the X-axis direction of the short side face 312 of the container 310 of the power storage element 300. The spacer wall portion 440 is arranged in opposition to the short side face 312 in the X-axis direction. That is, a pair of spacer wall portions 440 are arranged at positions sandwiching a pair of short side faces 312 of the container 310 in the X-axis direction. In the present embodiment, the spacer wall portion 440 is arranged in contact with the short side face 312, but can be arranged separately from the short side face 312. In this way, the spacer wall portions 420 to 440 are arranged so as to surround both sides in the Z-axis direction and both sides in the X-axis direction of the power storage element 300, and hold the power storage element 300.

[0067] The spacer 400a further has protrusions protruding from the spacer main body 410 in the Y-axis direction (first direction). Specifically, the spacer 400a has a first protrusion 411 protruding from the spacer main body 410 in the negative direction of the Y-axis (one side of the first direction), and a second protrusion 412 protruding from the spacer main body 410 in the positive direction of the Y-axis (the other side of the first direction). The first protrusion 411 and the second protrusion 412 are protrusions (ribs) extending in the Z-axis direction (second direction). The first protrusion 411 and the second protrusion 412 are arranged in the Y-axis direction in contact with the long side face 311 of the container 310 of the power storage element 300. As described above, the spacer main body 410 is arranged at substantially the same position as the container 310 of the power storage element 300 when viewed in the Y-axis direction, and the engaging portion 310a is arranged at the positive direction of the Z-axis end portion of the container 310 of the power storage element 300. For this reason, at least one of the first protrusion 411 and the second protrusion 412 (both in the present embodiment) extends in the Z-axis direction toward the engaging portion 310a.

[0068] The first protrusions 411 and the second protrusions 412 are arranged at different positions in at least one of the Z-axis direction (second direction) and the X-axis direction (third direction) orthogonal to the Y-axis direction (first direction). Specifically, the spacer 400a has two second protrusions 412, and the first protrusion 411 is arranged between the two second protrusions 412 in at least one of the Z-axis direction (second direction) and the X-axis direction (third direction). In the present embodiment, the first protrusion 411 and the second protrusion 412 are arranged at the same position in the Z-axis direction (second direction) and at different positions in the X-axis direction (third direction). Thus, the first protrusion 411 is arranged between the two second protrusions 412 in the X-axis direction (third direction). In detail, the spacer 400a has a plurality of first protrusions 411 and a plurality of second protrusions 412, and the plurality of first protrusions 411 and the plurality of second protrusions 412 are alternately arranged in the X-axis direction. That is, the first protrusion 411 is arranged between the two second protrusions 412 in the X-axis direction, and the second protrusion 412 is arranged between the two first protrusions 411 in the X-axis direction. In the present embodiment, the plurality of first protrusions 411 and the plurality of second protrusions 412 are alternately arranged at equal intervals in the X-axis direction.

[0069] The plurality of first protrusions 411 has a plurality of first long protrusions 411a and a plurality of first short protrusions 411b. The first long protrusion 411a is a long linear protrusion (rib) protruding from the spacer main body 410 in the negative Y-axis direction and extending in the Z-axis direction (second direction). In the central position of the spacer main body 410 in the Z-axis direction, the plurality of (five) first long protrusions 411a are arranged at equal intervals in the X-axis direction from one end portion to the other end portion of the spacer main body 410 in the X-axis direction.

[0070] The first short protrusion 411b is a point-like protrusion (rib) protruding from the spacer main body 410 in the negative Y-axis direction and having a shorter length in the Z-axis direction (second direction) than the first long protrusion 411a. In the present embodiment, the first short protrusion 411b has an oblong shape long in the Z-axis direction as viewed in the Y-axis direction, but can have an elliptical shape long in the Z-axis direction, an oblong shape or an elliptical shape long in the X-axis direction, a circular shape, or a polygonal shape such as a rectangular shape, and the like. As viewed in the X-axis direction (third direction), the first short protrusion 411b is arranged in the Z-axis direction (second direction) of the first long protrusion 411a. Specifically, the first short protrusion 411b is arranged closer to the Z-axis direction end portion of the spacer main body 410 than the first long protrusion 411a.

[0071] In the present embodiment, with respect to each first long protrusion 411a, two first short protrusions 411b are arranged on both sides of the first long protrusion 411a in the Z-axis direction (both end portions of the spacer main body 410). That is, the plurality of first protrusions 411 have two first short protrusions 411b, and the first long protrusion 411a is arranged between the two first short protrusions 411b as viewed in the X-axis direction (third direction). Thus, at the positive Z-axis direction end portion of the spacer main body 410, the plurality of (five) first short protrusions 411b are arranged at equal intervals in the X-axis direction from one end portion to the other end portion of the spacer main body 410. Similarly, at the negative Z-axis direction end portion of the spacer main body 410, the plurality of (five) first short protrusions 411b are arranged at equal intervals in the X-axis direction from one end portion to the other end portion of the spacer main body 410.

[0072] The first long protrusion 411a is preferably arranged at a position overlapping the electrode body (particularly, the flat portion thereof) of the power storage element 300 as viewed in the Y-axis direction, and the first short protrusion 411b is preferably arranged at a position not overlapping the electrode body (particularly, the flat portion thereof) as viewed in the Y-axis direction. The flat portion of the electrode body is a flat portion other than the connecting portion (tab, etc.) to the current collector in the case of a laminated or serpentine electrode body, and is a flat portion connecting the two curved portions at both end portions (excluding the connecting portion (tab, etc.) to the current collector) in the case of a wound electrode body.

[0073] In the present embodiment, the first long protrusion 411a is arranged closer to the first short protrusion 411b on the positive Z-axis direction side than to the first short protrusion 411b on the negative Z-axis direction side. That is, the first long protrusion 411a is arranged such that the center position of the first long protrusion 411a is on the positive Z-axis direction side of the center position of the spacer main body 410 in the Z-axis direction. As described above, the spacer main body 410 is arranged at substantially the same position as the container 310 of the power storage element 300 as viewed in the Y-axis direction. For this reason, the first long protrusion 411a is arranged such that the center position of the first long protrusion 411a is at a position different from the center position of the container 310 in the Z-axis direction (a position deviated toward the positive Z-axis direction in the present embodiment). In this way, the first long protrusion 411a and the first short protrusion 411b are arranged at appropriate positions in cooperation with the shape of the container 310 of the power storage element 300.

[0074] The protruding length (length in the protruding direction (Y-axis direction)) from the spacer main body 410 of the first long protruding portion 411a and the first short protruding portion 411b is different. In the present embodiment, the protruding length (length in the protruding direction (Y-axis direction)) from the spacer main body 410 is longer for the first long protruding portion 411a than for the first short protruding portion 411b. The protruding length of the first long protruding portion 411a is 1.1 times or more the protruding length of the first short protruding portion 411b. Depending on the shape of the container 310 of the power storage element 300, the protruding length (length in the protruding direction (Y-axis direction)) from the spacer main body 410 can be longer for the first short protruding portion 411b than for the first long protruding portion 411a. In this way, the first long protruding portion 411a and the first short protruding portion 411b are formed with appropriate protruding lengths in accordance with the shape of the container 310 of the power storage element 300.

[0075] Likewise, the plurality of second protruding portions 412 include a plurality of second long protruding portions 412a and a plurality of second short protruding portions 412b. The second long protruding portion 412a is a long linear protrusion (rib) that protrudes from the spacer main body 410 in the positive Y-axis direction and extends in the Z-axis direction (second direction). The second short protruding portion 412b is a point-like protrusion (rib) that protrudes from the spacer main body 410 in the positive Y-axis direction and has a shorter length in the Z-axis direction (second direction) than the second long protruding portion 412a. In the present embodiment, the second long protruding portion 412a and the second short protruding portion 412b have the same shape and size as the first long protruding portion 411a and the first short protruding portion 411b, and are arranged at positions offset in the X-axis direction from the positions at which the first long protruding portion 411a and the first short protruding portion 411b are arranged, as viewed in the Y-axis direction.

[0076] That is, as viewed in the X-axis direction (third direction), the second short protruding portion 412b is arranged in the Z-axis direction (second direction) from the second long protruding portion 412a. The plurality of second protruding portions 412 include two second short protruding portions 412b, and as viewed in the X-axis direction (third direction), the second long protruding portion 412a is arranged between the two second short protruding portions 412b. Specifically, at the central position in the Z-axis direction of the spacer main body 410, the plurality of (four) second long protruding portions 412a are arranged at equal intervals in the X-axis direction from one end portion to the other end portion of the spacer main body 410. At the positive Z-axis direction end portion of the spacer main body 410, the plurality of (four) second short protruding portions 412b are arranged at equal intervals in the X-axis direction from one end portion to the other end portion of the spacer main body 410. At the negative Z-axis direction end portion of the spacer main body 410, the plurality of (four) second short protruding portions 412b are arranged at equal intervals in the X-axis direction from one end portion to the other end portion of the spacer main body 410.

[0077] The second long protrusion 412a is arranged at a position different from the center position of the container 310 in the Z-axis direction (second direction) (in this embodiment, a position deviated in the positive direction of the Z-axis). The protrusion length from the spacer main body 410 (length in the protrusion direction (Y-axis direction)) of the second long protrusion 412a and the second short protrusion 412b is different. In this embodiment, the protrusion length from the spacer main body 410 is longer in the second long protrusion 412a than in the second short protrusion 412b, but the protrusion length from the spacer main body 410 can be longer in the second short protrusion 412b than in the second long protrusion 412a. The second long protrusion 412a and the second short protrusion 412b have the same shape and size as the first long protrusion 411a and the first short protrusion 411b, and therefore a detailed description is omitted. The second long protrusion 412a and the second short protrusion 412b can have a different shape or a different size from the first long protrusion 411a and the first short protrusion 411b.

[0078] [4 Explanation of Effects]

[0079] As described above, according to the power storage device 1 according to the present embodiment, the spacer 400a has the first protrusion 411 and the second protrusion 412 protruding from the spacer main body 410 in the negative direction of the Y-axis and the positive direction of the Y-axis (one side of the first direction and the other side of the first direction). In at least one direction (in this embodiment, the X-axis direction) of the Z-axis direction (second direction) and the X-axis direction (third direction), the first protrusion 411 and the second protrusion 412 are arranged at different positions. In this way, by arranging the first protrusion 411 and the second protrusion 412 of the spacer 400a at different positions in at least one direction (in this embodiment, the X-axis direction) of the Z-axis direction (second direction) and the X-axis direction (third direction), the first protrusion 411 and the second protrusion 412 are easily deformed in the Y-axis direction (first direction) with respect to each other. Thus, the spacer 400a can absorb the deviation in the size of the power storage element 300.

[0080] The first protrusion 411 and the second protrusion 412 of the spacer 400a are easily deformed in the Y-axis direction with respect to each other, and thus even if there is a deviation in the size of the power storage element 300, it is possible to suppress a situation in which the power storage element 300 is excessively pressed or not sufficiently pressed when the power storage element 300 is bulged. The faces (long side faces 311 of the container 310) of the two power storage elements 300 sandwiching the spacer 400a are sometimes different in size or different in the manner of bulging with respect to the Y-axis direction. In this case, the first protrusion 411 and the second protrusion 412 of the spacer 400a are easily deformed in the Y-axis direction with respect to each other, and thus it is possible to absorb the deviation in the size of the two power storage elements 300 or suppress the bulging.

[0081] The plurality of first protrusions 411 of the spacer 400a has a first long protrusion 411a that is long in the Z-axis direction (second direction), and a first short protrusion 411b that is shorter than the first long protrusion 411a in the Z-axis direction, and is disposed in the Z-axis direction of the first long protrusion 411a as viewed in the X-axis direction (third direction). In this way, by disposing protrusions (the first long protrusion 411a and the first short protrusion 411b) of different lengths in the Z-axis direction in the spacer 400a, even if the size deviation of the power storage element 300 in the Z-axis direction is complex, protrusions of lengths corresponding to the size deviation of the power storage element 300 can be disposed.

[0082] The size deviation of the power storage element 300 is that the central portion is larger than the end portions of the power storage element 300. For this reason, the relatively small size deviation of the power storage element 300 can be absorbed by the first short protrusion 411b of the spacer 400a, and the relatively large size deviation of the power storage element 300 can be absorbed by the first long protrusion 411a of the spacer 400a. Since the central portion of the power storage element 300 is more bulged than the end portions, the bulging of the power storage element 300 can be suppressed by the first long protrusion 411a of the spacer 400a.

[0083] By making the protruding lengths of the first long protrusion 411a and the first short protrusion 411b of the spacer 400a different, even if the size deviation of the power storage element 300 is complex, protrusions of protruding lengths corresponding to the size deviation of the power storage element 300 can be disposed. In the case where the protruding length is the first long protrusion 411a is longer than the first short protrusion 411b, the bulging of the power storage element 300 can be effectively suppressed by the first long protrusion 411a which is relatively long in the protruding length. In the case where the central portion of the power storage element 300 is slightly bulged from the beginning, by making the protruding length of the first long protrusion 411a shorter than the protruding length of the first short protrusion 411b, protrusions corresponding to the shape of the power storage element 300 can be disposed.

[0084] In the case where the size deviation of the power storage element 300 in the Z-axis direction (second direction) is biased, in the Z-axis direction, the center position of the first long protrusion 411a of the spacer 400a is disposed at a position different from the center position of the container 310 of the power storage element 300. Thereby, the bias of the size deviation of the power storage element 300 in the Z-axis direction can be suppressed. Even in the case where the bulging of the power storage element 300 in the Z-axis direction is biased, the bulging of the power storage element 300 can be more evenly suppressed by the first long protrusion 411a.

[0085] The protrusion (at least one of the first protrusion 411 and the second protrusion 412) of the spacer 400a extends toward the joint portion 310a of the container 310 of the power storage element 300, and is disposed in the vicinity of the joint portion 310a. Thus, even if the container 310 of the power storage element 300 is bulged, the bulging of the vicinity of the joint portion 310a of the container 310 is suppressed by the protrusion, and thus damage to the joint portion 310a is suppressed.

[0086] By disposing the first protrusion 411 between the two second protrusions 412 in the spacer 400a, the first protrusion 411 is deformed in the Y-axis direction (the first direction) between the two second protrusions 412. Thus, the first protrusion 411 can be deformed more stably.

[0087] In the above description, the effects of the first protrusion 411 (the first long protrusion 411a and the first short protrusion 411b) are also applicable to the second protrusion 412 (the second long protrusion 412a and the second short protrusion 412b). The effects of the spacer 400a are also applicable to the spacer 400c.

[0088] [5 Description of Modification]

[0089] The power storage device 1 according to the embodiment of the present application has been described above, but the present application is not limited to the above-described embodiment. The embodiment disclosed this time is merely an example, and all the modifications and alterations equivalent thereto are to be covered within the scope of the present application.

[0090] (Modification)

[0091] In the above-described embodiment, the shapes, sizes, and disposition positions of the first protrusion 411 (the first long protrusion 411a and the first short protrusion 411b) and the second protrusion 412 (the second long protrusion 412a and the second short protrusion 412b) are not limited. Figure 7 and Figure 8 are front and back views showing the structure of the spacer 400e according to the modification of the present embodiment. Specifically, Figure 7 (a) of Figure 7 (b) of Figure 6 (a) of Figure 6 (b) of Figure 8 (a) of Figure 8 (b) of Figure 7 (a) of Figure 7 (b) of

[0092] As Figure 7 andFigure 8 As shown, the first protrusions 411 of the spacer 400e in this modification example have first long protrusions 411c and first short protrusions 411d instead of the first long protrusions 411a and the first short protrusions 411b that the first protrusions 411 of the spacer 400a in the above embodiment have. The second protrusions 412 of the spacer 400e in this modification example have second long protrusions 412c and second short protrusions 412d instead of the second long protrusions 412a and the second short protrusions 412b that the second protrusions 412 of the spacer 400a in the above embodiment have. As for other structures of this modification example, the same as the above embodiment, detailed description is thus omitted.

[0093] The first long protrusions 411c in this modification example are shorter in the Z-axis direction than the first long protrusions 411a in the above embodiment, and the center positions of the first long protrusions 411c are disposed further in the Z-axis positive direction than the center positions of the first long protrusions 411a. In the above embodiment, five first long protrusions 411a are disposed, but in this modification example, the first long protrusions 411c are not disposed at both ends in the X-axis direction of the spacer main body 410, and three first long protrusions 411c are disposed. The first short protrusions 411d in this modification example are the same in shape, size, and disposition position as the first short protrusions 411b in the above embodiment, and detailed description is thus omitted. The second long protrusions 412c in this modification example are shorter in the Z-axis direction than the second long protrusions 412a in the above embodiment, and the center positions of the second long protrusions 412c are disposed at the same positions as the center positions of the second long protrusions 412a. The second short protrusions 412d in this modification example are longer in the Z-axis direction than the second short protrusions 412b in the above embodiment, and are disposed further in the Z-axis direction than the second short protrusions 412b.

[0094] According to such a structure, the first protrusions 411 and the second protrusions 412 are disposed at different positions in two directions orthogonal to the Y-axis direction (first direction) and to each other, that is, the Z-axis direction (second direction) and the X-axis direction (third direction). The first protrusions 411 are disposed between two second protrusions 412 in the X-axis direction (third direction). The second short protrusions 412d of the second protrusions 412 are disposed between the first long protrusions 411c and the first short protrusions 411d of the first protrusions 411 in the Z-axis direction (second direction). The first long protrusions 411c and the second long protrusions 412c are disposed at positions where the center positions of the first long protrusions 411c and the second long protrusions 412c in the Z-axis direction (second direction) are different from the center position of the container 310. The protrusion lengths of the first long protrusions 411c and the first short protrusions 411d from the spacer main body 410 are different, and the protrusion lengths of the second long protrusions 412c and the second short protrusions 412d from the spacer main body 410 are different.

[0095] As above, according to the power storage device related to the present modification example, the same effects as the above-described embodiments can be obtained. In particular, in the present modification example, the first protrusions 411 and the second protrusions 412 are disposed at positions different also in the Z-axis direction, so even if there is a deviation in the size of the power storage elements 300 in the Z-axis direction sandwiching the spacer 400e, the size deviation of the power storage elements 300 can be absorbed or the bulging can be suppressed. Since the bulging of the power storage elements 300 can be suppressed even if the first long protrusions 411c are not disposed at both ends in the X-axis direction of the spacer main body 410, the structure of the spacer 400e can be simplified.

[0096] (Other Modification Examples)

[0097] In the above-described embodiments, the first protrusions 411 and the second protrusions 412 extend in the Z-axis direction toward the junctions 310a of the containers 310 of the power storage elements 300, but can extend toward a direction inclined from the Z-axis direction or can extend in the X-axis direction. That is, the first protrusions 411 and the second protrusions 412 can be disposed (alternately disposed) at positions different in a direction inclined from the X-axis direction or in the Z-axis direction.

[0098] In the above-described embodiments, two first short protrusions 411b are disposed at both sides in the Z-axis direction of the first long protrusion 411a, but the disposition positions of the first long protrusion 411a and the first short protrusion 411b are not particularly limited. Two first long protrusions 411a can be disposed at both sides in the Z-axis direction of the first short protrusion 411b. Or, the first short protrusion 411b can be disposed at a position deviated from the Z-axis direction in the X-axis direction of the first long protrusion 411a. That is, the first short protrusion 411b can be disposed at a position in the Z-axis direction of the first long protrusion 411a as viewed in the X-axis direction. The lengths in the Z-axis direction of the first long protrusion 411a and the first short protrusion 411b are not particularly limited, and the first long protrusion 411a can be longer than the first short protrusion 411b. The same applies to the second protrusions 412.

[0099] In the above-described embodiments, the spacer 400a has a plurality of first protrusions 411, and the plurality of first protrusions 411 have a plurality of first long protrusions 411a and a plurality of first short protrusions 411b, but the number of the first long protrusions 411a and the first short protrusions 411b is not particularly limited. The spacer 400a can have only one first long protrusion 411a, can have only one first short protrusion 411b, or can have none of the first long protrusion 411a and the first short protrusion 411b. The same applies to the second protrusions 412.

[0100] In the above embodiment, the first long protrusion 411a is disposed at a position deviated from the center position of the container 310 of the power storage element 300 in the positive direction of the Z axis in the Z axis direction at the center position of the first long protrusion 411a, but can be disposed at a position deviated from the center position of the container 310 in the negative direction of the Z axis. The first long protrusion 411a can also be disposed at a position where the center position of the first long protrusion 411a is the same as the center position of the container 310 of the power storage element 300 in the Z axis direction. The same applies to the second protrusion 412.

[0101] In the above embodiment, in the plurality of first protrusions 411, the plurality of first long protrusions 411a have the same protruding length from the spacer main body 410, but the protruding length of the first long protrusion 411a can be arbitrarily different. The plurality of first short protrusions 411b have the same protruding length from the spacer main body 410, but the protruding length of the first short protrusion 411b can be arbitrarily different. The protruding length of the first long protrusion 411a and the first short protrusion 411b from the spacer main body 410 can be different, but can be the same. The same applies to the second protrusion 412.

[0102] In the above embodiment, the spacer 400a has the spacer wall portions 420 to 440, but is not limited to having all of these spacer wall portions. The spacer 400a can also not have the spacer wall portion 420, and can also not have one or both of the pair of spacer wall portions 440. The spacer 400a can also not have the spacer wall portion 430. That is, the spacer 400a can not be a holder that holds the power storage element 300.

[0103] In the above embodiment, all of the spacers 400a have the above structure, but any of the spacers 400a can not have the above structure. The same applies to the other spacers 400.

[0104] In the above embodiment, the spacers 400 (the spacers 400a to 400d) and the power storage elements 300 are alternately arranged in the Y axis direction, but can be a structure in which any of the spacers 400 is not arranged. One spacer 400a (or one spacer 400c) can be arranged to be sandwiched by two power storage elements 300.

[0105] In the above embodiment, the case 10 has the case main body 100 and the lid 200, but can not have the lid 200. In the above embodiment, two rows of power storage elements 300 composed of a plurality of power storage elements 300 are arranged in the X axis direction inside the case 10, but three or more rows of power storage elements can be arranged in the X axis direction, and only one row of power storage elements can be arranged. That is, three or more spacers 400 can be arranged in the X axis direction, and only one spacer 400 can be arranged.

[0106] Any combination of the above-described embodiments and variations thereof can be constructed within the scope of the present application.

[0107] Industrial applicability

[0108] The present application can be applied to an electric storage device or the like having an electric storage element such as a lithium-ion secondary battery.

[0109] Explanation of reference numerals

[0110] 1 Electric storage device

[0111] 10 Case

[0112] 100 Case main body

[0113] 200 Cover

[0114] 300 Electric storage element

[0115] 310 Container

[0116] 310a Joint portion

[0117] 311 Long side surface

[0118] 312 Short side surface

[0119] 313 Bottom surface

[0120] 320 Container main body portion

[0121] 330 Container cover portion

[0122] 340 Terminal

[0123] 350 Gasket

[0124] 400, 400a, 400b, 400c, 400d, 400e Spacer

[0125] 410 Spacer main body

[0126] 411 First protrusion

[0127] 411a, 411c First long protrusion

[0128] 411b, 411d First short protrusion

[0129] 412 Second protrusion

[0130] 412a, 412c Second long protrusion

[0131] 412b, 412d Second short protrusion

[0132] 420, 430, 440 Spacer wall portion

[0133] 600, 601, 602, 603 Busbars.

Claims

1. An electricity storage device comprising: a plurality of electricity storage elements; and a spacer disposed between the plurality of electricity storage elements in a first direction, the spacer having: a spacer main body; a first protrusion protruding from the spacer main body toward one side in the first direction; and a second protrusion protruding from the spacer main body toward the other side in the first direction, the first protrusion and the second protrusion being disposed at different positions in at least one of a second direction and a third direction that are orthogonal to the first direction and to each other.

2. The electricity storage device according to claim 1, wherein the spacer has a plurality of the first protrusions, the plurality of the first protrusions having: a long protrusion extending in the second direction; and a short protrusion disposed in the second direction from the long protrusion as viewed in the third direction, the second direction being shorter than the long protrusion.

3. The electricity storage device according to claim 2, wherein the plurality of the first protrusions have two of the short protrusions, the long protrusion being disposed between the two of the short protrusions as viewed in the third direction.

4. The electricity storage device according to claim 2 or 3, wherein protrusion lengths of the long protrusion and the short protrusion from the spacer main body are different.

5. The electricity storage device according to claim 2 or 3, wherein the plurality of the electricity storage elements each have a container, a center position of the long protrusion being disposed at a position different from a center position of the container in the second direction.

6. The electricity storage device according to any one of claims 1 to 3, wherein the plurality of the electricity storage elements each have a container formed with a joint portion joining two portions, at least one of the first protrusion and the second protrusion extending toward the joint portion.

7. The electricity storage device according to any one of claims 1 to 3, wherein the spacer has two of the second protrusions, the first protrusion being disposed between the two of the second protrusions in at least one of the second direction and the third direction. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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