Power storage device

Abstract

To provide a power storage device that can prevent damage to internal components.SOLUTION: In a power storage device 10 having power storage elements 210 and spacers 221 arranged in a row in a first direction, the spacer 221 has a side wall portion 280 facing the power storage element 210 in a second direction intersecting the first direction and extending in a third direction intersecting the first and second directions, and a projection 282b (285b) protruding from the side wall portion 280 in the second direction and the side wall portion 280 has a concave wall portion 282 (285) in which the protrusion 282b (285b) is provided and which is concave in a direction opposite to the protruding direction of the protrusion 282b (285b).SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an electricity storage device including an electricity storage element and a spacer. [Background technology]

[0002] Conventionally, there is known an energy storage device including an energy storage element and a spacer, the spacer having a wall portion around the energy storage element. For example, Patent Document 1 discloses a battery module (energy storage device) including a battery cell (energy storage element) and a spacer, the spacer having a side wall portion, a bottom wall portion, and an upper wall portion around the battery cell. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-174831 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a configuration in which the spacer has a wall portion around the storage element as in the above-mentioned conventional storage device, a gap (wobble) may occur between the wall portion and the storage element due to dimensional tolerances, etc. When a member is also arranged on the opposite side of the wall portion from the storage element, a gap (wobble) may occur between the wall portion and the member due to dimensional tolerances, etc. For example, in the above-mentioned conventional storage device, the side wall portion of the spacer is arranged between the storage element (battery cell) and the side plate, and the bottom wall portion of the spacer is arranged between the storage element and the base plate. For this reason, a gap may occur between the side wall portion of the spacer and the storage element or the side plate, or between the bottom wall portion of the spacer and the storage element or the base plate. In such a case, when the storage device is subjected to vibration or impact, etc., the storage element, etc. may move within the storage device, which may damage the internal members of the storage device.

[0005] The present invention was made by the present inventors by taking new notice of the above-mentioned problem, and has an object to provide an electricity storage device capable of suppressing damage to internal members. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, an energy storage device according to one embodiment of the present invention is an energy storage device comprising an energy storage element and a spacer arranged side by side in a first direction, wherein the spacer faces the energy storage element in a second direction intersecting the first direction and has a wall portion extending in a third direction intersecting the first direction and the second direction, and a protrusion protruding from the wall portion in the second direction, and the wall portion has the protrusion provided thereon and has a concave wall portion recessed in the opposite direction to the protruding direction of the protrusion.

[0007] According to this, in the energy storage device, the spacer aligned in the first direction with the energy storage element has a protrusion protruding in the second direction from a wall portion facing the energy storage element in the second direction and extending in the third direction. Furthermore, the wall portion of the spacer has a concave wall portion on which the protrusion is provided and recessed in the opposite direction to the protrusion direction of the protrusion. In this way, since the spacer has a protrusion protruding from the wall portion toward the energy storage element or in the opposite direction to the energy storage element, even if a gap (wobble) occurs between the wall portion and the energy storage element or a member on the opposite side of the energy storage element, the protrusion can fill the gap. As a result, even if vibration or impact is applied to the energy storage device, it is possible to suppress the movement of the energy storage element and the like within the energy storage device, and therefore it is possible to suppress damage to members inside the energy storage device.

[0008] Furthermore, when the spacer is provided with the above-mentioned protrusion, if the protrusion length of the protrusion is short, the protrusion may not be crushed sufficiently, and the spacer, the electric storage element, or the above-mentioned components may be damaged. For this reason, a concave wall portion that is recessed in the opposite direction to the protrusion direction is provided on the wall portion of the spacer, and the protrusion is provided on the concave wall portion. This allows the protrusion length to be increased, so that the protrusion may not be crushed sufficiently, and the spacer, the electric storage element, or the above-mentioned components may be prevented from being damaged. Therefore, damage to the internal components of the electric storage device may be prevented.

[0009] In addition, the concave wall portion may have a first wall portion on which the protrusion is provided, a second wall portion arranged at a position adjacent to the first wall portion in the third direction, and a deformation portion arranged between the first wall portion and the second wall portion, allowing greater deformation of the first wall portion relative to the second wall portion than other adjacent portions.

[0010] When the spacer is provided with the above-mentioned protrusion, if the gap between the wall of the spacer and the electric storage element or the member opposite the electric storage element is small or the protrusion is hard, the protrusion may not be crushed sufficiently, and the spacer, the electric storage element, or the member may be damaged. For this reason, a deformation portion that allows the first wall to be largely deformed relative to the second wall is disposed between the first wall and the second wall on which the protrusion is provided in the concave wall of the spacer. As a result, when the protrusion is not crushed sufficiently, the deformation portion causes the first wall to deform relative to the second wall, thereby suppressing damage to the spacer, the electric storage element, or the member. Therefore, damage to the members inside the electric storage device can be suppressed.

[0011] In addition, the concave wall portion may have a first wall portion on which the protrusion is provided, and a second wall portion arranged at a position adjacent to the first wall portion in the third direction, and the first wall portion may be thinner in the second direction than the second wall portion.

[0012] According to this, in the concave wall portion of the spacer, since the first wall portion is thinner than the second wall portion, even if a protrusion is provided on the first wall portion, the first wall portion can be prevented from protruding on the opposite side of the protrusion. As a result, even in a configuration in which a concave wall portion is provided on the wall portion of the spacer to prevent damage to members inside the electricity storage device, the concave wall portion can be prevented from protruding on the opposite side of the protrusion, thereby achieving space saving.

[0013] In addition, the concave wall portion may have a first wall portion on which the protrusion is provided, and a second wall portion arranged at a position adjacent to the first wall portion in the third direction, and the first wall portion may be arranged so that a surface opposite to the protrusion side of the second wall portion is positioned on the protrusion side.

[0014] According to this, in the concave wall portion of the spacer, the first wall portion provided with the protrusion is disposed on the side opposite to the protrusion side relative to the second wall portion, so that even if the first wall portion deforms in the direction opposite to the protrusion, the first wall portion can be prevented from protruding in the direction opposite to the protrusion. As a result, even in a configuration in which the wall portion of the spacer is provided with a concave wall portion to prevent damage to members inside the energy storage device, the concave wall portion can be prevented from protruding in the direction opposite to the protrusion, thereby enabling space saving.

[0015] Furthermore, the spacer may further include a side member facing the spacer in the second direction, and the side member may have a recess into which the concave wall portion is inserted, or a protrusion into which the concave wall portion is inserted.

[0016] According to this, the side member facing the spacer has a recess into which the recessed wall of the spacer is inserted, or a protrusion into which the recessed wall is inserted, so that the spacer can be positioned relative to the side member by utilizing the recessed wall. As a result, even if the power storage device is subjected to vibration or impact, the spacer and the power storage elements can be prevented from moving within the power storage device, and therefore damage to the internal components of the power storage device can be prevented.

[0017] The present invention can be realized not only as an electricity storage device but also as a spacer. Effect of the Invention

[0018] According to the electricity storage device of the present invention, damage to internal members can be suppressed. [Brief description of the drawings]

[0019] [Figure 1] 1 is a perspective view showing an external appearance of a power storage device according to an embodiment; [Diagram 2] 2 is a perspective view showing the inside of an exterior body with a main body and a lid separated in an energy storage device according to an embodiment; FIG. [Diagram 3] 2 is an exploded perspective view showing inner components of an exterior body of the energy storage device according to the embodiment; FIG. [Figure 4] FIG. 2 is an exploded perspective view illustrating each component of the electricity storage unit according to the embodiment. [Diagram 5] FIG. 2 is an exploded perspective view showing each component of the energy storage element according to the embodiment. [Figure 6] FIG. 2 is a perspective view showing a configuration of a spacer according to an embodiment. [Figure 7] 4A and 4B are an enlarged perspective view and a top view showing a configuration of a recessed wall portion of a side wall portion of the spacer according to the embodiment. [Figure 8] 4A and 4B are an enlarged perspective view and a top view showing a configuration of a flat wall portion of a rear wall portion of a spacer according to an embodiment. [Figure 9] FIG. 2 is a perspective view showing a configuration of a side member according to the embodiment. [Figure 10] 4 is a top view showing the positional relationship between a spacer, an energy storage element, and a side member in the embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, a description will be given of an energy storage device according to an embodiment (including modified examples) of the present invention with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, the arrangement and connection of the components, manufacturing processes, and the order of the manufacturing processes shown in the following embodiments are merely examples and are not intended to limit the present invention. Furthermore, the dimensions and the like are not strictly illustrated in each drawing. Furthermore, the same reference numerals are used for the same or similar components in each drawing.

[0021] In the following description and drawings, the longitudinal direction of the exterior body of the energy storage device, the arrangement direction of the energy storage unit and the electric equipment unit, the arrangement direction of the side members, the extension direction of the end members, the opposing direction of the short side surfaces of the container of the energy storage element, or the arrangement direction of a pair of electrode terminals in one energy storage element is defined as the X-axis direction. The arrangement direction of the energy storage element and the bus bar or the bus bar frame, or the arrangement direction of the main body and the lid of the container of the energy storage element is defined as the Y-axis direction. The arrangement direction of the main body and the lid of the exterior body of the energy storage device, the arrangement direction of the pair of end members, the arrangement direction of the energy storage element, the spacer, and the end members, the opposing direction of the long side surfaces of the container of the energy storage element, the flattening direction of the energy storage element, the stacking direction of the electrode plates of the electrode body of the energy storage element, or the up-down direction is defined as the Z-axis direction. These X-axis, Y-axis, and Z-axis directions are directions that intersect with each other (orthogonal in this embodiment). Note that, depending on the mode of use, it is possible that the Z-axis direction is not the up-down direction, but for convenience of explanation, the following description will be given assuming that the Z-axis direction is the up-down direction.

[0022] In the following description, for example, the positive X-axis direction indicates the direction of the X-axis arrow, and the negative X-axis direction indicates the opposite direction to the positive X-axis direction. The same applies to the Y-axis direction and the Z-axis direction. In the following, the Z-axis direction may also be called the first direction or arrangement direction, the X-axis direction may also be called the second direction, and the Y-axis direction may also be called the third direction. Furthermore, expressions indicating relative directions or attitudes, such as parallel and perpendicular, may also include cases where the directions or attitudes are not strictly the same. For example, two directions being perpendicular to each other not only means that the two directions are completely perpendicular to each other, but also means that the two directions are substantially perpendicular to each other, that is, includes a difference of, for example, about several percent.

[0023] (Embodiment) [1 General Description of Power Storage Device 10] First, a schematic configuration of an energy storage device 10 according to the present embodiment will be described. Fig. 1 is a perspective view showing the external appearance of the energy storage device 10 according to the present embodiment. Fig. 2 is a perspective view showing the inside of the exterior body 100 in the energy storage device 10 according to the present embodiment, with the main body and the lid of the exterior body 100 separated. Fig. 3 is an exploded perspective view showing the components inside the exterior body 100 of the energy storage device 10 according to the present embodiment.

[0024] The power storage device 10 is a device that can charge electricity from an external source and discharge electricity to the outside, and in this embodiment, has a substantially rectangular parallelepiped shape. For example, the power storage device 10 is a battery module (battery pack) used for power storage or power source. Specifically, the power storage device 10 is used as a battery for driving or starting an engine of 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 an electric railway. Examples of the 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 railway vehicle for the electric railway include a train, a monorail, a linear motor car, and a hybrid train equipped with both a diesel engine and an electric motor. The power storage device 10 can also be used as a stationary battery for home use or for a power generator.

[0025] 1 to 3, the power storage device 10 includes an exterior body 100, and an electricity storage unit 200 and an electric equipment unit 300 housed in the exterior body 100. In addition to the above components, the power storage device 10 may also include an exhaust section for exhausting gas discharged from the electricity storage unit 200 to the outside of the exterior body 100, and a connector connected to the electric equipment unit 300 by an electric wire or the like for transmitting signals to the outside.

[0026] The exterior body 100 is a box-shaped (approximately rectangular parallelepiped) container (module case) that constitutes the exterior body of the power storage device 10. In other words, the exterior body 100 is disposed outside the power storage unit 200 and the electric equipment unit 300, and fixes the power storage unit 200 and the electric equipment unit 300 at predetermined positions to protect them from impacts and the like. The exterior body 100 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), ABS resin, or a composite material thereof, or a metal with an insulating coating. The exterior body 100 thereby prevents the power storage unit 200 and the electric equipment unit 300 from coming into contact with external metal members, etc. Note that the exterior body 100 may be formed of a conductive member such as a metal as long as the electrical insulation of the power storage unit 200 and the electric equipment unit 300 is maintained.

[0027] The exterior body 100 has an exterior body main body 110 that constitutes the main body of the exterior body 100, and an exterior body lid body 120 that constitutes the lid body of the exterior body 100. The exterior body main body 110 is a bottomed rectangular tubular housing (casing) with an opening formed on the positive side of the Z axis, and houses the electricity storage unit 200 and the electric equipment unit 300. The exterior body main body 110 has a bottom wall portion 111, four side wall portions 112, and a plurality of protrusions 113.

[0028] The bottom wall 111 is disposed on the Z-axis negative side of the exterior body main body 110, and is a flat, rectangular wall that forms the bottom surface of the exterior body main body 110. A rib 111a is formed on the Z-axis positive surface of the bottom wall 111. The rib 111a is a convex portion that protrudes in the Z-axis positive direction from the Z-axis positive surface of the bottom wall 111, and a plurality of ribs 111a extending in the X-axis direction and the Y-axis direction are formed over almost the entire surface of the Z-axis positive surface of the bottom wall 111. The four side walls 112 are disposed on both sides in the X-axis direction and both sides in the Y-axis direction of the exterior body main body 110, and are four flat, rectangular walls that form two short side surfaces on both sides in the X-axis direction and two long side surfaces on both sides in the Y-axis direction of the exterior body main body 110.

[0029] The protrusions 113 are members that penetrate the bottom wall 111 in the Z-axis direction and protrude in the Z-axis positive direction from the surface of the bottom wall 111 in the Z-axis positive direction. In this embodiment, two protrusions 113 aligned in the Y-axis direction are disposed at each of the center in the X-axis direction and the end in the X-axis positive direction of the bottom wall 111. Each of the protrusions 113 is attached to the end member 230 and the side member 240 by inserting the portion protruding in the Z-axis positive direction from the bottom wall 111 into an opening (openings 230b and 244 described below) formed in the end member 230 and the side member 240.

[0030] For example, the protrusion 113 is a bolt such as a sealing bolt, and the male thread of the bolt is disposed so as to protrude in the Z-axis positive direction from the surface of the bottom wall 111 in the Z-axis positive direction beyond the rib 111a. The male thread of the protrusion 113 is screwed into a female thread formed in at least one of the openings 230b and 244, thereby attaching the bottom wall 111 to the end member 230 and the side member 240. In this embodiment, the male thread of the protrusion 113 passes through the opening 230b of the end member 230 and is screwed into a female thread of the opening 244 of the side member 240, thereby fixing the bottom wall 111 to the side member 240 with the end member 230 sandwiched therebetween.

[0031] In this manner, one of exterior body 100 and side member 240 (in this embodiment, exterior body 100) has a protrusion (protrusion 113) that protrudes toward the other (in this embodiment, side member 240), and the other has an opening (opening 244) into which the protrusion is inserted. Then, side member 240 is fixed to exterior body 100 by fixing the protrusion (protrusion 113) to the other (side member 240) within the opening (opening 244).

[0032] The exterior body cover 120 is a flat rectangular member that closes the opening of the exterior body 110. The exterior body cover 120 is joined to the exterior body 110, preferably in an airtight or watertight manner, by adhesive, heat sealing, ultrasonic welding, laser welding, or the like. A pair of external terminals 130, which are a pair of module terminals (general terminals) on the positive and negative sides, are arranged on the exterior body cover 120 at both ends in the negative X-axis direction and in the Y-axis direction. The power storage device 10 charges with electricity from the outside and discharges electricity to the outside via the pair of external terminals 130. The external terminals 130 are formed of a conductive member made of metal, such as aluminum, an aluminum alloy, copper, or a copper alloy.

[0033] In the energy storage unit 200, a plurality of energy storage elements 210 are arranged (stacked) in the Z-axis direction with the elements laid out horizontally (laying on their side), and are also arranged in the X-axis direction, so that the energy storage unit 200 has a shape that is flat in the Z-axis direction and elongated in the X-axis direction. Specifically, the energy storage unit 200 has a configuration in which the plurality of energy storage elements 210 arranged in the Z-axis direction and the X-axis direction are sandwiched in the Z-axis direction and the X-axis direction by a pair of end members 230 and a plurality (three) of side members 240 together with a spacer 220. A more detailed description of the configuration of the energy storage unit 200 will be given later.

[0034] The electric device unit 300 includes an electric device 310, an attachment member 320, and a busbar unit 330. The electric device 310 is an apparatus capable of monitoring the state of the energy storage element 210 included in the energy storage unit 200 and controlling the energy storage element 210. In the present embodiment, the electric device 310 is a flat rectangular member disposed and attached in the positive direction of the X-axis of the energy storage unit 200. The electric device 310 includes electric components such as a circuit board, a shunt resistor, and a connector that monitor the charging and discharging states of the energy storage element 210 and control the charging and discharging of the energy storage element 210. The electric device 310 has a configuration in which these electric components are housed in an insulating cover member.

[0035] The mounting member 320 is a flat plate-like member that mounts the electric device 310 to the power storage unit 200. The mounting member 320 is formed of, for example, any electrically insulating resin material that can be used for the exterior body 100. The mounting member 320 is disposed between the power storage unit 200 and the electric device 310, and is attached to the power storage unit 200 and the electric device 310 is attached to the mounting member 320. In the present embodiment, the mounting member 320 is attached to a side surface of the power storage unit 200 in the positive direction of the X axis, so that the electric device 310 is attached to the side surface of the power storage unit 200 in the positive direction of the X axis in an upright position (a position parallel to the YZ plane).

[0036] Specifically, the mounting member 320 is attached to an end member 230 and a side member 240 (described later) of the electricity storage unit 200. More specifically, the mounting member 320 has four protrusions 321 at both ends in the Z-axis direction and both ends in the Y-axis direction. The protrusions 321 have portions that protrude in the Z-axis direction toward the end member 230, and are attached to the end member 230 and the side member 240 by inserting the portions into openings (openings 230c and 244 (described later)) formed in the end member 230 and the side member 240. For example, the protrusions 321 are bolts, and the male threads of the bolts are screwed into female threads formed in at least one of the openings 230c and 244, thereby mounting the mounting member 320 to the end member 230 and the side member 240.

[0037] The bus bar unit 330 has a bus bar and a relay, and electrically connects the power storage unit 200 and the electric device 310, electrically connects the electric device 310 and the external terminal 130, and electrically connects the power storage unit 200 and the external terminal 130. The bus bar is a plate-shaped member that connects a bus bar 250 (described later) included in the power storage unit 200 to the electric device 310, connects the electric device 310 and the external terminal 130, connects the bus bar 250 to the relay, and connects the relay to the external terminal 130. The bus bar is formed of, for example, a conductive member made of a metal such as aluminum, an aluminum alloy, copper, a copper alloy, or nickel, or a combination thereof, or a conductive member other than a metal.

[0038] [2. Description of the Configuration of the Energy Storage Unit 200] Next, the configuration of the power storage unit 200 will be described in detail with reference to Fig. 4 in addition to Fig. 3. Fig. 4 is an exploded perspective view showing each component of the power storage unit 200 according to the present embodiment. Note that in Fig. 4, bus bar 250 and bus bar frame 251 of the power storage unit 200 are omitted.

[0039] As shown in Figures 3 and 4, the energy storage unit 200 has a plurality of energy storage elements 210 (211, 212), a plurality of spacers 220 (221, 222), a pair of end members 230 (231, 232), three side members 240, a plurality of bus bars 250, and a bus bar frame 251.

[0040] The energy storage element 210 is a secondary battery (single cell) capable of charging and discharging electricity, and more specifically, a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The energy storage element 210 has a flat rectangular parallelepiped shape (rectangular shape), and in this embodiment, eight energy storage elements 210 are arranged in the Z-axis direction and the X-axis direction in a horizontally placed (laid down) state (with the long side of the energy storage element 210 facing the Z-axis direction). Specifically, four energy storage elements 211 on the negative side of the X-axis are arranged (stacked) in the Z-axis direction (arrangement direction), and four energy storage elements 212 on the positive side of the X-axis are arranged (stacked) in the Z-axis direction (arrangement direction). The four energy storage elements 211 and the four energy storage elements 212 are arranged side by side in the X-axis direction. A detailed description of the configuration of the energy storage elements 210 (211, 212) will be described later.

[0041] The number of the energy storage elements 210 is not particularly limited, and any number of the energy storage elements 210 may be stacked (flat) in the Z-axis direction, or any number of the energy storage elements 210 may be arranged in the X-axis direction. That is, the energy storage unit 200 may have only one energy storage element 210. The shape of the energy storage element 210 is not limited to the above-mentioned rectangular shape, and may be other shapes such as a polygonal column shape, a cylindrical shape, an elliptical column shape, or an oblong column shape. The energy storage element 210 is not limited to a nonaqueous electrolyte secondary battery, and may be a secondary battery other than a nonaqueous electrolyte secondary battery, or may be a capacitor. The energy storage element 210 may not be a secondary battery, but may be a primary battery that can use stored electricity without the user having to charge it. The energy storage element 210 may be a battery using a solid electrolyte. The energy storage element 210 may be a pouch-type energy storage element.

[0042] The spacers 220 (221, 222) are disposed (arranged) alongside the energy storage elements 210 in the Z-axis direction (first direction, arrangement direction), and are flat, rectangular members that electrically insulate the energy storage elements 210 from other members. The spacers 220 (221, 222) are formed of, for example, any electrically insulating resin material that can be used for the exterior body 100 described above.

[0043] Specifically, the spacers 221 are intermediate spacers (inter-cell spacers) arranged adjacent to the energy storage elements 210 in the Z-axis direction. That is, the spacers 221 are arranged between two adjacent energy storage elements 210 (between the two energy storage elements 211 and between the two energy storage elements 212) to electrically insulate the two energy storage elements 210 from each other. In this embodiment, three spacers 221 are arranged corresponding to the four energy storage elements 211, but when the number of the energy storage elements 211 is other than four, the number of the spacers 221 is appropriately changed according to the number of the energy storage elements 211. The same applies to the energy storage elements 212.

[0044] The spacer 222 is an end spacer that is arranged at an end of the plurality of spacers 220 in the Z axis direction (first direction, arrangement direction), and is arranged adjacent to the end storage element 210 in the Z axis direction. The spacer 222 is arranged between the end storage element 210 (end storage element 211 and storage element 212) and the end member 230 (231, 232), and electrically insulates the end storage element 210 from the end member 230 (231, 232). That is, two spacers 222 are arranged on both sides in the Z axis direction of the four storage elements 211, and two spacers 222 are arranged on both sides in the Z axis direction of the four storage elements 212.

[0045] Spacer 220 (221, 222) has walls on both sides in the X-axis direction and both sides in the Y-axis direction, and is electrically insulated from other members arranged on both sides in the X-axis direction and both sides in the Y-axis direction of energy storage element 210. For example, spacer 220 (221, 222) has the walls arranged between energy storage element 210 and side member 240, and electrically insulates energy storage element 210 from side member 240. A detailed description of the configuration of spacer 220 (221) will be given later.

[0046] The end member 230 and the side member 240 are members (restraining members) that compress (restrain) the energy storage elements 210 from the outside in the Z-axis direction. That is, the end member 230 and the side member 240 sandwich the energy storage elements 210 and the spacers 220 from both sides in the Z-axis direction, thereby compressing (restraining) each of the energy storage elements 210 and the spacers 220 from both sides in the Z-axis direction. The end member 230 and the side member 240 are formed of metal members such as stainless steel, aluminum, aluminum alloy, iron, plated steel sheet, etc., but may also be formed of an insulating member such as a highly rigid resin.

[0047] The end members 230 (231, 232) are disposed at positions sandwiching the plurality of energy storage elements 210 (211 and 212) and the plurality of spacers 220 (221 and 222) in the Z-axis direction, and are a pair of flat-plate-shaped members (end plates) that sandwich them in the Z-axis direction. As a result, the pair of end members 230 collectively restrain the plurality of energy storage elements 210 and the plurality of spacers 220 in the Z-axis direction (collectively apply a restraining force in the Z-axis direction to the plurality of energy storage elements 210 and the plurality of spacers 220). The end member 231 is the end member 230 on the negative Z-axis direction side of the pair of end members 230, and the end member 232 is the end member 230 on the positive Z-axis direction side. The end members 230 (231, 232) may be block-shaped, rod-shaped, or other members instead of flat-plate-shaped members.

[0048] The side member 240 is a flat-plate-shaped member (side plate) disposed adjacent to the spacer 220 in the X-axis direction (second direction intersecting the first direction) and facing the spacer 220. Both ends of the side member 240 are attached to a pair of end members 230, and the side member 240 restrains the multiple energy storage elements 210 and the multiple spacers 220 by connecting the pair of end members 230. In other words, the side member 240 is disposed extending in the Z-axis direction so as to straddle the multiple energy storage elements 210 and the multiple spacers 220, and applies a restraining force to the multiple energy storage elements 210 etc. in the arrangement direction (Z-axis direction). The side member 240 need not be a flat-plate-shaped member, and may be a block-shaped or rod-shaped member, etc.

[0049] In this embodiment, three side members 240 are arranged in the negative X-axis direction of the multiple energy storage elements 211, between the multiple energy storage elements 211 and the multiple energy storage elements 212, and in the positive X-axis direction of the multiple energy storage elements 212. That is, in the X-axis direction (second direction), two sets of energy storage elements 210 and spacers 220 are arranged at positions sandwiching the central side member 240, and two side members 240 are arranged at positions sandwiching the two sets of energy storage elements 210 and spacers 220. Then, these three side members 240 are attached to both ends in the X-axis direction and the central part of a pair of end members 230 at both ends in the Z-axis direction. As a result, the end members 230 and the side members 240 sandwich and restrain the multiple energy storage elements 210 and the multiple spacers 220 from both sides in the X-axis direction and both sides in the Z-axis direction.

[0050] Specifically, the end members 230 (231, 232) have protruding portions 230a (231a, 232a), and are connected (joined) to the respective side members 240 by the protruding portions 230a. In this embodiment, three protruding portions 230a aligned in the Y-axis direction are arranged at the center and both ends of the end member 230 in the X-axis direction. The protruding portions 230a have portions that protrude in the Z-axis direction from the surface of the end member 230 facing the side member 240 toward the side member 240, and are attached to the side member 240 by being inserted into openings 243 formed in the side member 240.

[0051] For example, the protrusion 230a is a bolt, and the male thread of the bolt is screwed into the female thread formed in the opening 243, thereby attaching the end member 230 to the side member 240. Alternatively, the protrusion 230a is a self-tapping bolt (tapping bolt), and the end member 230 is attached to the side member 240 by screwing the bolt while forming a female thread in the opening 243. The arrangement position and the number of the protrusions 230a are not particularly limited. In addition, the method of connecting the end member 230 and the side member 240 may be other methods, such as welding, crimping, adhesion, or welding. A detailed description of the configuration of the side member 240 will be given later.

[0052] In addition, the end members 230 (231, 232) have the above-mentioned two openings 230b (231b, 232b) disposed between the three protruding portions 230a (231a, 232a) arranged in the Y-axis direction at the center and the end portion in the positive direction of the X-axis. That is, the three protruding portions 230a (231a, 232a) and the two openings 230b (231b, 232b) are disposed alternately in the Y-axis direction. The openings 230b (231b, 232b) are circular through-holes that penetrate the end members 230 (231, 232) in the Z-axis direction. At the end of the end member 230 (231, 232) in the negative X-axis direction, the above-mentioned two openings 230c (231c, 232c) are arranged between the three protruding parts 230a (231a, 232a) arranged in the Y-axis direction. That is, the three protruding parts 230a (231a, 232a) and the two openings 230c (231c, 232c) are arranged alternately in the Y-axis direction. The openings 230c (231c, 232c) are circular through-holes that penetrate the end member 230 (231, 232) in the Z-axis direction.

[0053] The bus bar 250 is a flat member connected to the energy storage elements 210. Specifically, the bus bar 250 is arranged in the negative Y-axis direction of the energy storage elements 210, and is connected (joined) to the electrode terminals 210b of the energy storage elements 210 and the bus bar unit 330. That is, the bus bar 250 connects the electrode terminals 210b of the energy storage elements 210 to each other, and also connects the electrode terminals 210b of the energy storage elements 210 at the end to the bus bar unit 330. In the present embodiment, the bus bar 250 and the electrode terminals 210b of the energy storage elements 210 are connected (joined) by welding, but may be connected (joined) by bolt fastening or the like. The bus bar 250 is formed of, for example, a conductive member made of a metal such as aluminum, an aluminum alloy, copper, a copper alloy, or nickel, or a combination thereof, or a conductive member other than a metal. In this embodiment, the bus bar 250 connects two storage elements 210 in parallel to form four sets of storage element groups, and connects the four sets of storage element groups in series; however, the bus bar 250 may connect all eight storage elements 210 in series, or may have another configuration.

[0054] Bus bar frame 251 is a flat rectangular insulating member capable of electrically insulating bus bar 250 from other members and regulating the position of bus bar 250. Bus bar frame 251 is formed of, for example, any electrically insulating resin material usable for exterior body 100. Bus bar frame 251 is disposed in the negative Y-axis direction of multiple energy storage elements 210 and is positioned relative to multiple energy storage elements 210. Bus bar 250 is also positioned on bus bar frame 251. As a result, bus bar 250 is positioned relative to multiple energy storage elements 210 and joined to electrode terminals 210b of the multiple energy storage elements 210.

[0055] [3. Description of the Configuration of Energy Storage Element 210] Next, the configuration of the energy storage element 210 will be described in detail. Fig. 5 is an exploded perspective view showing each component of the energy storage element 210 according to this embodiment. Specifically, Fig. 5 shows an exploded view of each part of the energy storage element 210 shown in Fig. 4 in a vertically placed (standing) state. Note that since all eight energy storage elements 210 (four energy storage elements 211 and four energy storage elements 212) have the same configuration, the configuration of one energy storage element 210 will be described below.

[0056] As shown in FIG. 5, the energy storage element 210 includes a container 210a, a pair of electrode terminals 210b (positive electrode side and negative electrode side), and a pair of gaskets 210c (positive electrode side and negative electrode side). A pair of gaskets 210d (positive electrode side and negative electrode side), a pair of current collectors 210e (positive electrode side and negative electrode side), and an electrode body 210f are housed inside the container 210a. An electrolyte (non-aqueous electrolyte) is sealed inside the container 210a, but is not shown. There is no particular limit to the type of electrolyte as long as it does not impair the performance of the energy storage element 210, and various electrolytes can be selected. In addition to the above components, a spacer disposed on the side or below the electrode body 210f, an insulating film that wraps the electrode body 210f, or an insulating sheet that covers the outer surface of the container 210a may be disposed.

[0057] The container 210a is a rectangular parallelepiped (rectangular or box-shaped) case having a container body 210a1 with an opening and a container lid 210a2 that closes the opening of the container body 210a1. With this configuration, the container 210a can be sealed by, for example, welding the container body 210a1 and the container lid 210a2 together after the electrode body 210f and the like are accommodated inside the container body 210a1. The materials of the container body 210a1 and the container lid 210a2 are not particularly limited, but are preferably weldable metals such as stainless steel, aluminum, aluminum alloy, iron, and plated steel sheet.

[0058] The container body 210a1 is a rectangular cylindrical member with a bottom that constitutes the main body of the container 210a, and has an opening on the negative Y-axis side. That is, the container body 210a1 has a pair of rectangular and planar (flat) long side surfaces on both sides in the Z-axis direction, a pair of rectangular and planar (flat) short side surfaces on both sides in the X-axis direction, and a rectangular and planar (flat) bottom surface on the positive Y-axis side. The container lid 210a2 is a rectangular plate-like member that constitutes the lid of the container 210a, and is disposed extending in the X-axis direction on the negative Y-axis side of the container body 210a1.

[0059] The electrode body 210f is an electricity storage element (power generation element) formed by laminating a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate is a positive electrode active material layer formed on a positive electrode base layer which is a current collector foil made of a metal such as aluminum or an aluminum alloy. The negative electrode plate is a negative electrode active material layer formed on a negative electrode base layer which is a current collector foil made of a metal such as copper or a copper alloy. As the active material used for the positive electrode active material layer and the negative electrode active material layer, any known material can be used as long as it can absorb and release lithium ions. In this embodiment, the electrode body 210f is a wound type (so-called vertically wound type) electrode body formed by winding the electrode plates (positive electrode plate and negative electrode plate) around a winding axis (a virtual axis parallel to the X-axis direction) extending in the X-axis direction.

[0060] Here, the electrode plates (positive and negative electrode plates) of the electrode body 210f are stacked in the Z-axis direction, so the Z-axis direction is also called the stacking direction. That is, the electrode body 210f is formed by stacking the electrode plates in the stacking direction. The electrode body 210f has a pair of flat parts 210f1 aligned in the Z-axis direction and a pair of curved parts 210f2 aligned in the Y-axis direction by winding the electrode plates, and the stacking direction is the stacking direction of the electrode plates in the flat part 210f1. The flat part 210f1 is a flat part that connects the ends of the pair of curved parts 210f2, and the curved part 210f2 is a part that is curved in a semicircular shape or the like so as to protrude in the Y-axis direction. The stacking direction can also be defined as the direction in which the flat surface of the flat part 210f1 faces or the opposing direction of the pair of flat parts 210f1. Therefore, the multiple storage elements 211 arranged in the arrangement direction (Z-axis direction) can also be said to be arranged in the stacking direction, and the multiple storage elements 212 arranged in the arrangement direction (Z-axis direction) can also be said to be arranged in the stacking direction.

[0061] In addition, since the electrode body 210f is wound with the positive and negative plates shifted from each other in the X-axis direction, the positive and negative plates have portions (active material layer non-formed portions) where the active material is not formed (coated) and the base material layer is exposed at the ends in the shifted direction. In other words, the electrode body 210f has connection portions 210f3 at both ends in the X-axis direction that protrude from the flat portion 210f1 and the curved portion 210f2 on both sides in the X-axis direction and are connected to the current collector 210e by stacking the active material layer non-formed portions of the positive and negative plates.

[0062] The electrode body 210f may be an electrode body of any shape, such as a so-called horizontally wound electrode body formed by winding an electrode plate around a winding axis extending in the Y-axis direction, a laminated (stacked) electrode body formed by stacking a plurality of flat electrode plates, or a bellows-shaped electrode body in which an electrode plate is folded into a bellows shape. In the case of a horizontally wound electrode body, the flat portion is a flat portion other than the curved portion and the connection portion (tab) with the current collector, and in the case of a laminated (stacked) and bellows-shaped electrode body, the flat portion is a flat portion other than the connection portion (tab) with the current collector.

[0063] The electrode terminals 210b are terminals (positive and negative terminals) of the energy storage element 210, and are disposed on the container lid portion 210a2 so as to protrude in the negative Y-axis direction. The electrode terminals 210b are electrically connected to the positive and negative plates of the electrode body 210f via the current collector 210e. The electrode terminals 210b are formed of a conductive material such as a metal, such as aluminum, an aluminum alloy, copper, or a copper alloy.

[0064] The current collector 210e is a conductive member (positive electrode current collector and negative electrode current collector) electrically connected to the electrode terminal 210b and the connection part 210f3 of the electrode body 210f. The current collector 210e is made of aluminum, an aluminum alloy, copper, a copper alloy, or the like. The gaskets 210c and 210d are flat, electrically insulating sealing members disposed between the container lid part 210a2 and the electrode terminal 210b and between the current collector 210e and the container lid part 210a2. The gaskets 210c and 210d are made of, for example, any electrically insulating resin material usable for the exterior body 100.

[0065] [4 Explanation of the structure of spacer 221] Next, the configuration of the spacer 221 will be described in detail. Since all the spacers 221 included in the electricity storage unit 200 have the same configuration, the following description will be given by illustrating one spacer 221. Fig. 6 is a perspective view showing the configuration of the spacer 221 according to this embodiment. Specifically, Fig. 6 shows an enlarged view of the spacer 221 shown in Fig. 4.

[0066] FIG. 7 is a perspective view and a top view showing an enlarged configuration of the recessed wall portions 282 and 285 of the side wall portion 280a of the spacer 221 according to the present embodiment. Specifically, FIG. 7(a) is a perspective view showing an enlarged configuration of the recessed wall portions 282 and 285 of the side wall portion 280a surrounded by a dashed line indicated by VII in the spacer 221 shown in FIG. 6. FIG. 7(b) is a perspective view showing the configuration of FIG. 7(a) from the opposite side (X-axis minus direction). FIG. 7(c) is a top view showing the configuration of FIG. 7(a) from the Z-axis plus direction. FIG. 8 is a perspective view and a top view showing an enlarged configuration of the flat wall portion 291 of the rear wall portion 290 of the spacer 221 according to the present embodiment. Specifically, FIG. 8(a) is a perspective view showing an enlarged configuration of the flat wall portion 291 of the rear wall portion 290 surrounded by a dashed line indicated by VIII in the spacer 221 shown in FIG. 6. FIG. 8(b) is a top view of the configuration of FIG. 8(a) as viewed from the positive direction of the Z axis.

[0067] As shown in these figures, the spacer 221 has a spacer main body 260, a front wall portion 270, a pair of side wall portions 280 (280a and 280b), and a rear wall portion 290. The spacer main body 260 is a flat, rectangular portion constituting the main body of the spacer 221, and is disposed at a position facing the energy storage element 210 in the Z-axis direction (first direction). Specifically, the spacer main body 260 faces the long side surface of the container 210a of the energy storage element 210, and is disposed between the long side surfaces of the two energy storage elements 210. In this embodiment, the spacer main body 260 has a plurality of ribs 261, 262, and 263 formed on the main surface 260a on both sides in the Z-axis direction, which extend in the X-axis direction, but a rib extending in the Y-axis direction may be formed, or a rib may not be formed.

[0068] The front wall portion 270 is a flat wall portion protruding from an edge of the spacer body 260 in the negative Y-axis direction on both sides in the Z-axis direction, facing the energy storage element 210 in the Y-axis direction, and disposed extending in the X-axis direction. Specifically, the front wall portion 270 is disposed for each of the energy storage elements 210 disposed on both sides in the Z-axis direction of the spacer 221 so as to cover approximately half in the Z-axis direction of the surface in the negative Y-axis direction of the container lid portion 210a2 of the energy storage element 210. More specifically, the front wall portion 270 is disposed so as to cover approximately half in the Z-axis direction of the portion of the energy storage element 210 in the negative Y-axis direction other than the gas exhaust valve and electrode terminal 210b of the container lid portion 210a2.

[0069] The pair of sidewalls 280 are plate-shaped walls protruding from both ends of the spacer body 260 in the X-axis direction in both sides in the Z-axis direction, facing the energy storage element 210 in the X-axis direction (second direction), and arranged extending in the Y-axis direction (third direction intersecting the first and second directions). Specifically, the pair of sidewalls 280 are arranged for each of the energy storage elements 210 arranged on both sides of the spacer 221 in the Z-axis direction so as to cover approximately half in the Z-axis direction of the faces (short side faces) on both sides in the X-axis direction of the container body 210a1 of the energy storage element 210. Hereinafter, of the pair of sidewalls 280, the sidewall 280 on the positive X-axis direction side is also referred to as sidewall 280a, and the sidewall 280 on the negative X-axis direction side is also referred to as sidewall 280b.

[0070] The side wall portion 280a has a spacer protrusion 281 and recessed wall portions 282 to 285. Similarly to the side wall portion 280a, the side wall portion 280b also has a spacer protrusion 281 and recessed wall portions 282 to 285. That is, the side wall portion 280b has a shape that is symmetrical to the side wall portion 280a with respect to the YZ plane that passes through the center of the spacer main body 260. For this reason, in the following, the configuration of the side wall portion 280a will be described in detail, and the description of the configuration of the side wall portion 280b will be simplified or omitted.

[0071] The spacer protrusion 281 is a protrusion that protrudes in the positive direction of the X-axis. That is, the spacer protrusion 281 protrudes toward the side member 240. Specifically, the spacer protrusion 281 is a rectangular column-shaped (in this embodiment, a square tube-shaped) protrusion that extends in the Z-axis direction and protrudes in the positive direction of the X-axis, and two spacer protrusions 281 are arranged at both ends of the side wall 280a in the Y-axis direction. In this embodiment, the two spacer protrusions 281 have the same protrusion amount in the positive direction of the X-axis, and are arranged protruding further in the positive direction of the X-axis than the concave wall portions 282 to 285. In the Y-axis direction, the spacer protrusion 281 in the negative direction of the Y-axis has a larger width than the spacer protrusion 281 in the positive direction of the Y-axis.

[0072] The concave wall portions 282 to 285 are disposed between two spacer protruding portions 281, and are rectangular recessed portions in the positive or negative X-axis direction as viewed from the Z-axis direction. Specifically, the concave wall portions 282 and 283 are U-shaped (inverted C-shaped) recessed portions as viewed from the Z-axis direction, with the surface in the negative X-axis direction recessed rectangularly in the positive X-axis direction, and are disposed extending in the Z-axis direction. The surfaces in the positive X-axis direction of the concave wall portions 282 and 283 protrude in the positive X-axis direction, so that they can be said to be bulging protruding portions extending in the Z-axis direction protruding in a rectangular shape in the positive X-axis direction as viewed from the Z-axis direction. In this embodiment, two concave wall portions 282 are disposed between two spacer protruding portions 281, and two concave wall portions 283 are disposed between the two concave wall portions 282. These recessed wall portions 282 and 283 are equally recessed in the positive X-axis direction, are equally protruding in the positive X-axis direction, and are also equally wide in the Y-axis direction.

[0073] The concave wall portions 284 and 285 are generally C-shaped recesses when viewed from the Z-axis direction, with the surface facing the positive X-axis direction recessed in a rectangular shape toward the negative X-axis direction, and are arranged to extend in the Z-axis direction. The concave wall portions 284 and 285 are also said to be bulging convex portions extending in the Z-axis direction and protruding in a rectangular shape toward the negative X-axis direction when viewed from the Z-axis direction, since the surface facing the negative X-axis direction protrudes in the negative X-axis direction. In this embodiment, two concave wall portions 284 are arranged between each of the two spacer convex portions 281 and each of the two concave wall portions 282, and one concave wall portion 284 is arranged between the two concave wall portions 283. Two concave wall portions 285 are arranged between each of the two concave wall portions 282 and each of the two concave wall portions 283.

[0074] That is, the five concave wall portions, the three concave wall portions 284 and the two concave wall portions 285, are arranged alternately in the Y-axis direction with the four concave wall portions, the two concave wall portions 282 and the two concave wall portions 283, between the two spacer protrusions 281. The concave wall portions 284 and 285 are equally recessed in the negative X-axis direction, are equally protruding in the negative X-axis direction, and are equally wide in the Y-axis direction. The concave wall portions 284 and 285 are narrower in the Y-axis direction than the concave wall portions 282 and 283.

[0075] Here, the concave wall portions 283 and 284 are flat wall portions (recesses), whereas the concave wall portions 282 and 285 are provided with protrusions (protrusions 282b and 285b described below) and have a shape that is recessed in the opposite direction to the protrusion direction of the protrusions. The configurations of these concave wall portions 282 and 285 will be described in detail below. Note that all of the concave wall portions 282 of the side wall portion 280 (280a and 280b) have the same configuration, so the following will describe in detail one concave wall portion 282. The same is true for the concave wall portion 285.

[0076] 7, the concave wall portion 282 has a first wall portion 282a provided with a protrusion 282b, a second wall portion 282c, and a deformation portion 282d. The first wall portion 282a is disposed protruding from the spacer main body 260 on both sides in the Z axis direction, and is a flat rectangular wall portion parallel to the YZ plane facing the energy storage element 210 in the X axis direction (second direction). The protrusion 282b is a protruding portion protruding from the first wall portion 282a toward the energy storage element 210 in the X axis direction (second direction). In other words, the portion of the first wall portion 282a where the protrusion 282b is formed is connected to the spacer main body 260 and protrudes from the spacer main body 260 in the Z axis direction (first direction).

[0077] The protrusion 282b is a rib that protrudes in the negative X-axis direction from the center of the first wall portion 282a in the Y-axis direction, and is arranged extending in the Z-axis direction from the end of the first wall portion 282a to the main surface 260a of the spacer main body 260. In this embodiment, the protrusion 282b has a shape in which the edge in the positive Z-axis direction is inclined in the negative Z-axis direction as it approaches the negative X-axis direction, such that the length in the Z-axis direction becomes shorter as it moves from the first wall portion 282a in the negative X-axis direction.

[0078] The position of the protrusion 282b is not particularly limited, and for example, the protrusion 282b may be disposed at the end of the first wall portion 282a in the Y-axis direction, or at the end or center in the Z-axis direction. The shape and number of the protrusions 282b are also not particularly limited, and the length in the Z-axis direction may be longer toward the negative X-axis direction, or the length in the Z-axis direction may be the same throughout the X-axis direction, or a plurality of protrusions 282b may be arranged side by side in the Y-axis or Z-axis directions. In this embodiment, the protrusions 282b are also arranged in the rounded portion of the boundary between the first wall portion 282a and the spacer main body 260, but the protrusions 282b may not be arranged in the rounded portion in order to make the protrusions 282b easier to crush.

[0079] The second wall portion 282c, like the first wall portion 282a, is disposed protruding from the spacer body 260 on both sides in the Z axis direction, and is a flat rectangular wall portion parallel to the YZ plane facing the energy storage element 210 in the X axis direction. The second wall portion 282c is disposed at a position adjacent to the first wall portion 282a in the Y axis direction (third direction). Specifically, the pair of second wall portions 282c are disposed at positions sandwiching the first wall portion 282a in the Y axis direction (third direction).

[0080] Here, the first wall portion 282a is thinner in the X-axis direction (second direction) than the second wall portion 282c. Specifically, the surface of the first wall portion 282a opposite to the protrusion 282b side is disposed closer to the protrusion 282b side than the second wall portion 282c. That is, the first wall portion 282a and the second wall portion 282c are disposed at the same position in the X-axis direction on the surface in the negative X-axis direction, and the first wall portion 282a is disposed in the negative X-axis direction on the surface in the positive X-axis direction than the second wall portion 282c. In other words, the concave wall portion 282 has a shape in which the surface in the positive X-axis direction is concave in the negative X-axis direction at the position of the first wall portion 282a.

[0081] The deformation portion 282d is disposed between the first wall portion 282a and the second wall portion 282c, and is a portion that allows the first wall portion 282a to deform more with respect to the second wall portion 282c than other adjacent portions. A pair of deformation portions 282d is disposed between the first wall portion 282a and a pair of second wall portions 282c. In this embodiment, the deformation portion 282d is a through portion formed by penetrating the portion between the first wall portion 282a and the second wall portion 282c in the X-axis direction (second direction). Specifically, the deformation portion 282d is a long cutout (slit) extending in the Z-axis direction, which is cut out from the edge in the Z-axis positive direction toward the Z-axis negative direction in the portion between the first wall portion 282a and the second wall portion 282c in the concave wall portion 282. In this embodiment, the deformation portion 282d extends to the curved portion of the boundary between the first wall portion 282a and the spacer main body 260, but it does not have to extend to that curved portion, or it may extend beyond that curved portion.

[0082] Further, the deformation portion 282d is not limited to a notch (slit), and may be, for example, a through hole extending in the Z-axis direction, or a through portion such as a plurality of through holes arranged in the Z-axis direction. Alternatively, the deformation portion 282d may not be a through portion, but may be a thin portion having a thickness in the X-axis direction (second direction) smaller than the first wall portion 282a and the second wall portion 282c. In this case, the deformation portion 282d may be a flat thin portion, or may be a bellows-shaped thin portion. Furthermore, the deformation portion 282d may have both the through portion and the thin portion. In this way, it is sufficient that the deformation portion 282d has at least one of a through portion and a thin portion.

[0083] Next, the configuration of the concave wall portion 285 will be described in detail. The concave wall portion 285 has a first wall portion 285a provided with a protrusion 285b, a second wall portion 285c, and a deformation portion 285d. The first wall portion 285a is disposed protruding from the spacer main body 260 on both sides in the Z axis direction, and is a flat, rectangular wall portion parallel to the YZ plane that faces the energy storage element 210 in the X axis direction (second direction). The protrusion 285b is a protruding portion that protrudes from the first wall portion 285a toward the opposite side to the energy storage element 210 in the X axis direction (second direction). That is, the portion of the first wall portion 285a where the protrusion 285b is formed is connected to the spacer main body 260 and protrudes from the spacer main body 260 in the Z axis direction (first direction).

[0084] The protrusion 285b is a rib that protrudes in the positive X-axis direction from the center of the first wall portion 285a in the Y-axis direction, and is arranged to extend in the Z-axis direction. In this embodiment, the protrusion 285b is a trapezoidal protrusion as seen from the X-axis direction, the length of which decreases in the Z-axis direction from the first wall portion 285a toward the positive X-axis direction, and two protrusions 285b are arranged side by side in the Z-axis direction. The two protrusions 285b may be formed as one protrusion by extending in the Z-axis direction and connecting them. The arrangement position, shape, and number of the protrusions 285b are not particularly limited, and various modifications similar to those of the above-mentioned protrusion 282b are possible.

[0085] The second wall portion 285c is a flat rectangular wall portion parallel to the YZ plane, disposed adjacent to the first wall portion 285a in the Y axis direction (third direction) similarly to the above-mentioned second wall portion 282c. Specifically, the pair of second wall portions 285c are disposed at positions sandwiching the first wall portion 285a in the Y axis direction (third direction). The first wall portion 285a and the second wall portion 285c have the same thickness in the X axis direction (second direction).

[0086] The deformation portion 285d is disposed between the first wall portion 285a and the second wall portion 285c, and is a portion that allows the first wall portion 285a to deform more significantly relative to the second wall portion 285c than other adjacent portions. A pair of deformation portions 285d is disposed between the first wall portion 285a and the pair of second wall portions 285c. In this embodiment, the deformation portion 285d is a through portion (cutout) formed by penetrating the portion between the first wall portion 285a and the second wall portion 285c in the X-axis direction (second direction), but various deformations (through hole, thin portion, etc.) similar to those of the above-mentioned deformation portion 282d are possible.

[0087] 6 and 8, the rear wall 290 is a flat wall protruding from an edge of the spacer body 260 in the positive Y-axis direction on both sides in the Z-axis direction, facing the energy storage elements 210 in the Y-axis direction, and disposed extending in the X-axis direction. Specifically, the rear wall 290 is disposed so as to cover approximately half in the Z-axis direction of the surface (bottom surface) in the positive Y-axis direction of the container body 210a1 of the energy storage elements 210 for each of the energy storage elements 210 disposed on both sides of the spacer 221 in the Z-axis direction.

[0088] The rear wall 290 has two flat wall portions 291 at both ends in the X-axis direction. The flat wall portion 291 is not a wall portion that is recessed or protruding like the concave wall portion 282, but is a flat wall portion. The rear wall portion 290 has a first wall portion 291a provided with a protrusion 291b, a second wall portion 291c, and a deformed portion 291d. The first wall portion 291a is disposed protruding from the spacer main body 260 on both sides in the Z-axis direction, and is a flat rectangular wall portion parallel to the XZ plane that faces the energy storage element 210 in the Y-axis direction. The protrusion 291b is a protruding portion that protrudes from the first wall portion 291a toward the energy storage element 210 in the Y-axis direction. That is, the portion of the first wall portion 291a where the protrusion 291b is formed is connected to the spacer main body 260 and protrudes from the spacer main body 260 in the Z-axis direction.

[0089] The protrusion 291b is a rib protruding from both ends of the first wall portion 291a in the X-axis direction in the negative Y-axis direction, and is arranged extending in the Z-axis direction. The protrusion 291b has a similar configuration to the above-mentioned protrusion 282b, so a detailed description will be omitted. The second wall portion 291c is a flat, rectangular wall portion parallel to the XZ plane, arranged at a position adjacent to the first wall portion 291a in the X-axis direction. A pair of second walls 291c are arranged at positions sandwiching the first wall portion 291a in the X-axis direction. The second wall portion 291c also has a similar configuration to the above-mentioned second wall portion 282c, so a detailed description will be omitted. The deformation portion 291d is arranged between the first wall portion 291a and the second wall portion 291c, and is a portion that allows the first wall portion 291a to deform larger relative to the second wall portion 291c than other adjacent portions. A pair of deformation portions 291d are arranged between the first wall portion 291a and the pair of second walls 291c. The deformation portion 291d has a similar configuration to the above-mentioned deformation portion 282d, and therefore a detailed description thereof will be omitted.

[0090] Although the configuration of the spacer 221 has been described above, the spacer 222 also has a similar configuration to the spacer 221. That is, all the spacers 222 have walls with the same configuration as the front wall portion 270 of the spacer 221, the pair of side wall portions 280 (280a and 280b), and half of the rear wall portion 290 in the Z-axis direction.

[0091] [5. Description of the configuration of the side member 240] Next, the configuration of the side member 240 will be described in detail. Since all of the side members 240 of the electricity storage unit 200 have the same configuration, the following description will be given by illustrating one side member 240. Fig. 9 is a perspective view showing the configuration of the side member 240 according to the present embodiment. Specifically, Fig. 9 shows an enlarged view of the side member 240 shown in Fig. 4.

[0092] 9, the side member 240 has a side protrusion 241 in which the above-mentioned openings 243 and 244 are formed, and a side recess 242. In the present embodiment, five side protrusions 241 and four side recesses 242 are arranged alternately in the Y-axis direction.

[0093] The side protrusion 241 is a protruding portion of the side member 240 that protrudes in the X-axis direction and extends in the Z-axis direction. In this embodiment, the side protrusion 241 is a rectangular columnar (rectangular parallelepiped) portion that protrudes in a rectangular shape on both sides of the side member 240 in the X-axis direction and extends from one end to the other end of the side member 240 in the Z-axis direction. Here, the side protrusion 241 in which the opening 243 is formed is referred to as the side protrusion 241a, and the side protrusion 241 in which the opening 244 is formed is referred to as the side protrusion 241b. That is, three side protrusions 241a and two side protrusions 241b are arranged alternately in the Y-axis direction. Two openings 243 extending in the Z-axis direction are formed at both ends of the side protrusion 241a in the Z-axis direction, and two openings 244 extending in the Z-axis direction are formed at both ends of the side protrusion 241b in the Z-axis direction.

[0094] As described above, the side protrusion 241a is fixed to the pair of end members 230 in the Z axis direction by inserting the protrusions 230a (231a, 232a) of the pair of end members 230 (231, 232) into the openings 243 on both sides in the Z axis direction. The side protrusion 241b is fixed to the exterior body 100 in the Z axis direction by inserting the protrusion 113 of the exterior body main body 110 of the exterior body 100 into the opening 244 in the negative Z axis direction. Note that with respect to the side member 240 on the negative X axis direction side, the side protrusion 241b is fixed to the electric equipment unit 300 in the Z axis direction by inserting the protrusion 321 of the mounting member 320 of the electric equipment unit 300 into the openings 244 on both sides in the Z axis direction.

[0095] The side recess 242 is a portion of the side member 240 that is recessed in the X-axis direction and extends in the Z-axis direction, and is disposed adjacent to the side protrusions 241 (241a, 241b). In the present embodiment, the side recess 242 is a flat rectangular (cuboid) portion that is recessed in a rectangular shape from both sides of the side member 240 in the X-axis direction and extends from one end of the side member 240 in the Z-axis direction to the other end.

[0096] [6. Description of Positional Relationship between Spacer 221, Energy Storage Element 210, and Side Member 240] Next, the positional relationship between the spacer 221, the energy storage element 210, and the side member 240 will be described in detail. Fig. 10 is a top view showing the positional relationship between the spacer 221, the energy storage element 210, and the side member 240 according to this embodiment. Specifically, Fig. 10(a) shows the configuration when the spacer 221, the energy storage element 210, and the side member 240 are assembled, as viewed from the positive direction of the Z axis. Fig. 10(b) shows an enlarged view of the recessed wall portions 282 and 285 of the side wall portion 280a of the spacer 221 in Fig. 10(a) and the configuration around them.

[0097] 10, side wall portions 280 (280a and 280b) of spacer 221 are disposed on both sides of energy storage element 210 in the X-axis direction, and rear wall portion 290 is disposed in the positive direction of energy storage element 210 in the Y-axis direction. Side members 240 are disposed on both sides of side wall portions 280 (280a and 280b) in the X-axis direction. In other words, side wall portions 280 (280a and 280b) are disposed between energy storage element 210 and side members 240, and are disposed in a state where they are sandwiched between energy storage element 210 and side members 240.

[0098] The spacer protrusion 281 of the side wall portion 280 is disposed outside the end portion of the side member 240 in the Y-axis direction and protrudes toward the side member 240. The two concave wall portions 282 and the two concave wall portions 283 are inserted into the four side recesses 242 of the side member 240, respectively. The five side protrusions 241 of the side member 240 are inserted into the three concave wall portions 284 and the two concave wall portions 285, respectively. Specifically, the three side protrusions 241a are inserted into the three concave wall portions 284, and the two side protrusions 241b are inserted into the two concave wall portions 285.

[0099] Then, the protrusion 282b of the concave wall portion 282 abuts against the energy storage element 210, and the protrusion 285b of the concave wall portion 285 abuts against the side protrusion 241b of the side member 240. In the present embodiment, all the spacers 220 (all the spacers 221 and all the spacers 222) have the same configuration as described above, so that the protrusions 285b of all the spacers 220 abut against the side protrusion 241b of the side member 240. The protrusion 291b (not shown in FIG. 10) of the flat wall portion 291 of the rear wall portion 290 abuts against the energy storage element 210. Note that the protrusion 282b protrudes in the negative X-axis direction beyond the concave wall portion 285 so as to be able to abut against the energy storage element 210. Since it is sufficient for the protrusion 285b to come into contact with the side convex portion 241b, the protrusion 285b protrudes less than the protrusion 282b and does not protrude in the positive direction of the X-axis beyond the concave wall portion 282. In addition, the distance (gap) between the first wall portion 282a and the side concave portion 242 is greater than the distance between the second wall portion 282c and the side concave portion 242.

[0100] The energy storage device 10 also includes two sets of energy storage elements 210 and spacers 221 at positions sandwiching a side member 240 in the X-axis direction. That is, the side member 240 is disposed between a side wall portion 280a of the spacer 221 disposed in the Z-axis direction of the energy storage element 211 and a side wall portion 280b of the spacer 221 disposed in the Z-axis direction of the energy storage element 212. The portion of the side member 240 on the negative X-axis direction side and the side wall portion 280a have the above-mentioned configuration, and the portion of the side member 240 on the positive X-axis direction side and the side wall portion 280b have the above-mentioned configuration.

[0101] [7 Explanation of Effects] As described above, according to the energy storage device 10 of the embodiment of the present invention, the spacer 221 has the projections 282b, 285b projecting in the second direction from the side wall portion 280 that faces the energy storage element 210 in the second direction (X-axis direction) and extends in the third direction (Y-axis direction). Furthermore, the side wall portion 280 of the spacer 221 has the projections 282b, 285b provided thereon, and has recessed wall portions 282, 285 recessed in the opposite direction to the projections 282b, 285b. In this manner, the spacer 221 has the projection 282b projecting from the side wall portion 280 toward the energy storage element 210, and the projection 285b projecting in the opposite direction to the energy storage element 210 (toward the side member 240). Therefore, even if a gap (wobble) occurs between the side wall portion 280 and the energy storage element 210 or the member (side member 240) on the opposite side to the energy storage element 210, the protrusion 282b or 285b can fill the gap. As a result, even if the energy storage device 10 is subjected to vibration or impact, the energy storage element 210 and the like can be prevented from moving inside the energy storage device 10, and therefore damage to the members inside the energy storage device 10 can be prevented.

[0102] Furthermore, when the spacer 221 is provided with the protrusions 282b, 285b, if the protrusion length of the protrusions 282b, 285b is short, the protrusions 282b, 285b may not be crushed sufficiently, and the spacer 221, the energy storage element 210, or the above-mentioned members (side member 240), etc. may be damaged. For this reason, the side wall portion 280 of the spacer 221 is provided with recessed wall portions 282, 285 recessed in the opposite direction to the protrusion direction of the protrusions 282b, 285b, and the protrusions 282b, 285b are provided on the recessed wall portions 282, 285. This allows the protrusion length of the protrusions 282b, 285b to be increased, and therefore it is possible to prevent the spacer 221, the energy storage element 210, or the above-mentioned members from being damaged due to the protrusions 282b, 285b not being crushed sufficiently. Therefore, it is possible to prevent the members inside the energy storage device 10 from being damaged.

[0103] Furthermore, when the spacer 221 is provided with the protrusion 282b, if the gap between the side wall portion 280 and the energy storage element 210 is small or if the protrusion 282b is hard, the protrusion 282b may not be crushed sufficiently, which may damage the spacer 221, the energy storage element 210, etc. Similarly, for the protrusion 285b, if the gap between the side wall portion 280 and the member (side member 240) on the opposite side to the energy storage element 210 is small or if the protrusion 285b is hard, the protrusion 285b may not be crushed sufficiently, which may damage the spacer 221, the member, etc. For this reason, in the concave wall portions 282, 285, the deformation portions 282d, 285d that enable the first wall portions 282a, 285a to be largely deformed with respect to the second wall portions 282c, 285c are disposed between the first wall portions 282a, 285a and the second wall portions 282c, 285c on which the projections 282b, 285b are provided. As a result, when the projections 282b, 285b are not sufficiently crushed, the first wall portions 282a, 285a are deformed with respect to the second wall portions 282c, 285c by the deformation portions 282d, 285d, and damage to the spacer 221, the energy storage element 210, or the corresponding members can be suppressed. Therefore, damage to the members inside the energy storage device 10 can be suppressed.

[0104] Furthermore, in the concave wall portion 282, the first wall portion 282a is thinner than the second wall portion 282c, so that even if the protrusion 282b is provided on the first wall portion 282a, the first wall portion 282a can be prevented from protruding on the opposite side of the protrusion 282b. As a result, even in a configuration in which the concave wall portion 282 is provided on the side wall portion 280 of the spacer 221 to prevent damage to the internal members of the power storage device 10, the concave wall portion 282 can be prevented from protruding on the opposite side of the protrusion 282b, so that space can be saved.

[0105] In addition, in the concave wall portion 282, the first wall portion 282a provided with the protrusion 282b has a surface (e.g., an outer surface) opposite to the protrusion 282b side disposed closer to the protrusion 282b side (e.g., on the inner side) than the second wall portion 282c. Therefore, even if the first wall portion 282a is deformed in the opposite direction to the protrusion 282b (e.g., on the outer side), the first wall portion 282a can be prevented from protruding to the opposite side to the protrusion 282b. As a result, even in a configuration in which the concave wall portion 282 is provided on the side wall portion 280 of the spacer 221 to prevent damage to the internal members of the power storage device 10, the concave wall portion 282 can be prevented from protruding to the opposite side to the protrusion 282b, so that space can be saved.

[0106] Moreover, the side member 240 facing the spacer 221 has a side recess 242 into which the recessed wall portions 282, 283 of the spacer 221 are inserted, and a side protrusion 241 into which the recessed wall portions 284, 285 are inserted. Therefore, the spacer 221 can be positioned relative to the side member 240 by utilizing the recessed wall portions 282, 283, 284, or 285. This makes it possible to prevent the spacer 221 and the energy storage elements 210, etc. from moving within the energy storage device 10 even if the energy storage device 10 is subjected to vibration or impact, and therefore makes it possible to prevent damage to the members inside the energy storage device 10.

[0107] In addition, since the portion of the first wall portion 282a where the protrusion 282b is formed is connected to the spacer main body 260 and protrudes from the spacer main body 260, the deformation of the portion relative to the second wall portion 282c can be suppressed more than when the portion is not connected to the spacer main body 260. This can suppress the portion from deforming too much relative to the second wall portion 282c, causing damage to the spacer 221 or creating a gap between the spacer 221 and the energy storage element 210. Similarly, the protrusion 285b can suppress the spacer 221 from being damaged or creating a gap between the spacer 221 and the member (side member 240) on the opposite side to the energy storage element 210. Therefore, damage to the members inside the energy storage device 10 can be suppressed. The same can be said about the flat wall portion 291.

[0108] Moreover, by configuring the deforming portion 282d to have at least one of a through portion that penetrates a portion between the first wall portion 282a and the second wall portion 282c and a thin portion that is thinner than the first wall portion 282a and the second wall portion 282c, the deforming portion 282d can be easily formed. This makes it possible to easily prevent damage to members inside the power storage device 10. The same can be said about the deforming portion 285d. The same can be said about the flat wall portion 291.

[0109] Furthermore, since the spacer 221 has a pair of deformation portions 282d between the first wall portion 282a and the pair of second wall portions 282c, the first wall portion 282a can be easily deformed relative to the second wall portion 282c, and the deformation can be well-balanced. This can further prevent damage to the internal members of the power storage device 10. The same can be said about the deformation portion 285d. The same can be said about the flat wall portion 291.

[0110] Furthermore, since the protrusion 285b protrudes toward the opposite side to the energy storage element 210, even if a gap (wobble) occurs between the first wall portion 285a and the member (side member 240) on the opposite side to the energy storage element 210, the protrusion 285b can fill the gap. This makes it possible to suppress the energy storage element 210 and the like from moving inside the energy storage device 10 even if vibration or impact is applied to the energy storage device 10. Furthermore, even if the protrusion 285b is pressed against the member (side member 240), the deformation portion 285d deforms the first wall portion 285a relative to the second wall portion 285c, thereby suppressing damage to the spacer 221 or the member. Therefore, it is possible to suppress damage to the members inside the energy storage device 10.

[0111] [8 Explanation of Variations] Although the power storage device 10 according to the embodiment of the present invention (including its modified examples) has been described above, the present invention is not limited to this embodiment. In other words, the embodiment disclosed here is illustrative and not restrictive in all respects, and the scope of the present invention includes all modifications within the meaning and scope equivalent to the claims.

[0112] For example, in the above embodiment, a plurality of spacers 220 are arranged, but only one spacer 220 may be arranged. That is, only one spacer 221 may be arranged, only one spacer 222 may be arranged, or a configuration in which either one of the spacers 221 and 222 is not arranged may be used. Even when the spacer 221 is not arranged, the spacer 222 can perform the same function as the spacer 221 by having a configuration of a wall portion, etc., similar to that of the spacer 221 described above.

[0113] In the above embodiment, the spacer 221 has a pair of second walls 282c at positions sandwiching the first wall 282a, and has a pair of deformation portions 282d between the first wall 282a and the pair of second walls 282c. However, the spacer 221 may have the second wall 282c only on one side of the first wall 282a, and may have only one deformation portion 282d between the first wall 282a and the second wall 282c. The same applies to the concave wall 285 and the flat wall 291.

[0114] In the above embodiment, the first wall portion 282a of the recessed wall portion 282 of the side wall portion 280 of the spacer 221 is thinner than the second wall portion 282c. However, the first wall portion 282a may have the same thickness as the second wall portion 282c, or the second wall portion 282c may be thicker.

[0115] In the above embodiment, the first wall portion 282a of the concave wall portion 282 of the side wall portion 280 of the spacer 221 is arranged such that the surface of the first wall portion 282a facing the protrusion 282b is closer to the protrusion 282b side than the second wall portion 282c. However, the first wall portion 282a may be arranged such that the surface facing the protrusion 282b is closer to the protrusion 282b side than the second wall portion 282c.

[0116] In the above embodiment, the first wall portion 285a of the concave wall portion 285 of the side wall portion 280 of the spacer 221 has the same thickness as the second wall portion 285c. However, the first wall portion 285a may be thinner or thicker than the second wall portion 285c. Also, the first wall portion 285a may be arranged so that the surface opposite to the protrusion 285b side is closer to the protrusion 285b side than the second wall portion 285c, or the surface opposite to the protrusion 285b side is closer to the second wall portion 285c than the second wall portion 285c. The same applies to the flat wall portion 291.

[0117] In the above embodiment, the flat wall portion 291 is a flat wall portion, but it may be a concave wall portion similar to the concave wall portions 282, 285, etc. Alternatively, the concave wall portions such as the concave wall portions 282, 285, etc. may be flat walls rather than concave.

[0118] In the above embodiment, the concave wall portions 284 and 285 have the same shape, and the width between the pair of walls facing each other in the Y-axis direction in the recess is the same. However, the width between the pair of walls of the concave wall portions 284 and 285 may be different. For example, the width between the pair of walls of the concave wall portions 284 and 285 may be gradually increased or decreased from the concave wall portion at the end in the Y-axis negative direction to the concave wall portion at the end in the Y-axis positive direction. This allows a gap to be formed between the concave wall portions 284 and 285 and the side protrusion portion 241 of the side member 240, so that positional deviations due to dimensional tolerances during manufacturing can be absorbed.

[0119] In the above embodiment, the side member 240 has the side protrusions 241 protruding on both sides in the X-axis direction. However, the side protrusions 241 may protrude only on one side in the X-axis direction, or the side member 240 may be a flat member that does not have the side protrusions 241. In other words, the side member 240 does not have to have at least one of the side recesses 242 into which the recessed wall portions 282, 283 of the spacer 221 are inserted and the side protrusions 241 inserted into the recessed wall portions 284, 285.

[0120] In the above embodiment, the energy storage unit 200 has two energy storage elements 210 (211 and 212) arranged in the X-axis direction. However, the energy storage unit 200 may have three or more energy storage elements 210 arranged in the X-axis direction, or may have only one energy storage element 210 in the X-axis direction.

[0121] In the above embodiment, any of the multiple spacers 221 may not have the above configuration, any of the multiple side members 240 may not have the above configuration, and any of the multiple storage elements 210 may not have the above configuration.

[0122] In the above embodiment, it is not necessary for the power storage device 10 to include all of the above-mentioned components. For example, the power storage device 10 may not include components (members or parts) that do not contribute to the above-mentioned effects or that can achieve the above-mentioned effects without them.

[0123] Any combination of the components included in the above-described embodiment and its modified examples is also included within the scope of the present invention.

[0124] The present invention can be realized not only as the power storage device 10 but also as the spacer 220. [Industrial Applicability]

[0125] The present invention can be applied to an electricity storage device including an electricity storage element such as a lithium ion secondary battery. [Explanation of symbols]

[0126] 10. Energy storage device 100 Exterior body 112, 280, 280a, 280b side wall 130 External terminal 200 Energy Storage Unit 210, 211, 212 Energy storage element 210a container 210b Electrode terminal 210e Current collector 210f electrode body 220, 221, 222 Spacer 230, 231, 232 End members 240 Side member 241, 241a, 241b Side protrusions 242 Side recess 250 Busbar 260 Spacer body 270 Front wall 281 Spacer protrusion 282, 283, 284, 285 Concave wall 282a, 285a, 291a First wall 282b, 285b, 291b protrusions 282c, 285c, 291c Second wall section 282d, 285d, 291d Deformation section 290 Rear wall 291 Flat wall section 300 Electrical Equipment Units

Claims

1. An electricity storage device including electricity storage elements and spacers arranged side by side in a first direction, The spacer is a wall portion facing the energy storage element in a second direction intersecting the first direction and extending in a third direction intersecting the first direction and the second direction; a protrusion protruding from the wall portion in the second direction, the wall portion has a concave wall portion on which the protrusion is provided and which is concave in a direction opposite to a direction in which the protrusion protrudes, The concave wall portion is a first wall portion provided with the protrusion; a second wall portion disposed adjacent to the first wall portion in the third direction; a deformation portion disposed between the first wall portion and the second wall portion, the deformation portion enabling a larger deformation of the first wall portion relative to the second wall portion than other adjacent portions. Energy storage device.

2. A power storage device comprising a power storage element and a spacer arranged side by side in a first direction, The spacer is a wall portion facing the energy storage element in a second direction intersecting the first direction and extending in a third direction intersecting the first direction and the second direction; a protrusion protruding from the wall portion in the second direction, the wall portion has a concave wall portion on which the protrusion is provided and which is concave in a direction opposite to a direction in which the protrusion protrudes, The concave wall portion is a first wall portion provided with the protrusion; a second wall portion disposed adjacent to the first wall portion in the third direction, The first wall portion has a smaller thickness in the second direction than the second wall portion. Energy storage device.

3. A power storage device comprising a power storage element and a spacer arranged side by side in a first direction, The spacer is a wall portion facing the energy storage element in a second direction intersecting the first direction and extending in a third direction intersecting the first direction and the second direction; a protrusion protruding from the wall portion in the second direction, the wall portion has a concave wall portion on which the protrusion is provided and which is concave in a direction opposite to a direction in which the protrusion protrudes, The concave wall portion is a first wall portion provided with the protrusion; a second wall portion disposed adjacent to the first wall portion in the third direction, The first wall portion has a surface on the opposite side to the protrusion side from the second wall portion and is disposed on the protrusion side. Energy storage device.

4. A power storage device comprising a power storage element and a spacer arranged side by side in a first direction, The spacer is a wall portion facing the energy storage element in a second direction intersecting the first direction and extending in a third direction intersecting the first direction and the second direction; a protrusion protruding from the wall portion in the second direction, the wall portion has a concave wall portion on which the protrusion is provided and which is concave in a direction opposite to a direction in which the protrusion protrudes, The power storage device further comprises: a side member facing the spacer in the second direction, The side member has a recess into which the recessed wall portion is inserted, or a protrusion into which the recessed wall portion is inserted. Energy storage device.

5. An electricity storage device including electricity storage elements and spacers arranged side by side in a first direction, The spacer is a wall portion facing the energy storage element in a second direction intersecting the first direction and extending in a third direction intersecting the first direction and the second direction; a protrusion protruding from the wall portion in the second direction, the wall portion has a concave wall portion on which the protrusion is provided and which is concave in a direction opposite to a direction in which the protrusion protrudes, The protrusion is a rib that is crushed when it comes into contact with another member. Energy storage device.

6. An electricity storage device including electricity storage elements and spacers arranged side by side in a first direction, The spacer is a wall portion facing the energy storage element in a second direction intersecting the first direction and extending in a third direction intersecting the first direction and the second direction; a protrusion protruding from the wall portion in the second direction, the wall portion has a concave wall portion on which the protrusion is provided and which is concave in a direction opposite to a direction in which the protrusion protrudes, The protrusion protrudes beyond the recessed wall portion in a protruding direction of the protrusion. Energy storage device.

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