Power storage device

Abstract

To provide a power storage device that can suppress damage to a spacer.SOLUTION: In a power storage device 10 having power storage elements 210 and spacers 221 arranged in an array direction, the spacers 221 have a spacer body 260 having a planar first surface 260a, which is one side in the array direction, and a planar second surface 260b, which is the other side, first convex portions 261, 262, and 263 arranged on the first surface 260a and extending along the 260a, and second convex portions 264, 265, and 266 disposed on the second surface 260b and positioned adjacent to the first convex portions 261, 262, and 263 when viewed from the array direction.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 that includes energy storage elements and spacers arranged in an arrangement direction, and has a convex portion formed on the surface of the spacer in the arrangement direction. For example, Patent Document 1 discloses a battery pack (energy storage device) that includes a plurality of single cells (energy storage elements) arranged in an arrangement direction and a spacer, and has a first convex portion and a second convex portion (convex portion) formed on the surface of the spacer in the arrangement direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-128991 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a configuration in which a convex portion is formed on the spacer, as in the above-mentioned conventional energy storage device, the convex portion is compressed by the energy storage element, and stress is concentrated on the convex portion, which may damage the spacer. In particular, if a convex portion is also formed on the back side of the convex portion of the spacer, stress is concentrated on the convex portions on both sides of the spacer, and if the convex portion of the spacer is long, stress is concentrated over the long convex portion. In such a case, the risk of damage to the spacer increases.

[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 spacers. [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 energy storage elements and a spacer arranged in an arrangement direction, the spacer having a spacer body having a planar first surface which is one surface in the arrangement direction and a planar second surface which is the other surface, a first convex portion arranged on the first surface and extending along the first surface, and a second convex portion arranged on the second surface, the second convex portion being arranged at a position adjacent to the first convex portion when viewed from the arrangement direction.

[0007] According to this, in the energy storage device, the spacer arranged in the arrangement direction with the energy storage elements has a first convex portion arranged on one planar first surface and extending along the first surface, and a second convex portion arranged on the other planar second surface and adjacent to the first convex portion as viewed from the arrangement direction. Here, if a long first convex portion is arranged on the first surface of the spacer, stress is concentrated along the long first convex portion, and the spacer may be damaged. Furthermore, if a second convex portion is arranged on the second surface of the spacer at a position overlapping the first convex portion as viewed from the arrangement direction, stress is concentrated on the first convex portion and the second convex portion, and the spacer may be damaged. For this reason, on the second surface of the spacer, the second convex portion is arranged at a position adjacent to the first convex portion (a position not overlapping the first convex portion) as viewed from the arrangement direction. This makes it possible to distribute the stress applied to the first convex portion and the second convex portion, and to suppress the concentration of stress on the first convex portion and the second convex portion. Therefore, damage to the spacer can be suppressed.

[0008] The first convex portion and the second convex portion may be arranged to extend in the same direction.

[0009] According to this, in the spacer, the first convex portion on the first surface and the second convex portion on the second surface are provided extending in the same direction, so that stress is easily distributed to the first convex portion and the second convex portion arranged in adjacent positions, thereby making it possible to prevent stress from concentrating on the first convex portion and the second convex portion, and therefore to prevent damage to the spacer.

[0010] Moreover, the spacer may have two of the first convex portions, and the second convex portion may be disposed between the two first convex portions as viewed from the arrangement direction.

[0011] According to this, in the spacer, the second convex portion on the second surface is disposed between the two first convex portions on the first surface when viewed from the arrangement direction, so that stress is easily distributed to the first convex portion and the second convex portion, which makes it possible to prevent stress from concentrating on the first convex portion and the second convex portion, thereby making it possible to prevent damage to the spacer.

[0012] In addition, the spacer may have a plurality of the first convex portions and a plurality of the second convex portions, and the plurality of the first convex portions and the plurality of the second convex portions may be arranged alternately when viewed from the arrangement direction.

[0013] According to this, in the spacer, the multiple first convex portions on the first surface and the multiple second convex portions on the second surface are alternately arranged when viewed from the arrangement direction, which makes it easy to distribute stress between the first convex portions and the second convex portions, thereby making it possible to prevent stress from concentrating on the first convex portions and the second convex portions, and therefore to prevent damage to the spacer.

[0014] In addition, the spacer may have a wall portion facing the storage element in the extension direction of at least one of the first convex portion and the second convex portion, and the at least one convex portion may be positioned at a distance from the wall portion.

[0015] According to this, in the spacer, at least one of the first convex portion on the first surface and the second convex portion on the second surface is disposed away from the wall portion facing the energy storage element, so that the at least one convex portion is easily deformed. This makes it possible to suppress stress concentration on the at least one convex portion, thereby suppressing damage to the spacer.

[0016] The present invention can be realized not only as an electricity storage device but also as a spacer. Effect of the Invention

[0017] According to the electricity storage device of the present invention, damage to the spacer can be suppressed. [Brief description of the drawings]

[0018] [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] 2A and 2B are a top view and a bottom view showing a configuration of a spacer according to an embodiment. [Figure 8] 1 is a cross-sectional view showing a configuration of a spacer according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] 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.

[0020] 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.

[0021] 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.

[0022] (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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] The protrusion 113 is a member that penetrates the bottom wall 111 in the Z-axis direction and protrudes 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 the center in the X-axis direction and the end in the X-axis positive direction of the bottom wall 111. Each protrusion 113 is attached to the end member 230 and the side member 240 by inserting a portion protruding in the Z-axis positive direction from the bottom wall 111 into an opening (openings 230b and 244 described later) formed in the end member 230 and the side member 240. For example, the protrusion 113 is a bolt such as a sealing bolt, and is screwed into an opening 244 of the side member 240 in a state where it penetrates the end member 230.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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).

[0033] 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.

[0034] 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.

[0035] [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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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 arranged 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 on the side member 240 side toward the side member 240, and are attached to the side member 240 by inserting the portions into openings 243 formed in the side member 240. For example, the protruding portions 230a are bolts or self-tapping bolts (tapping bolts), etc., and are screwed into the openings 243 of the side member 240.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] [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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] [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, one spacer 221 will be illustrated and described below. 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. FIG. 7 is a top view and a bottom view showing the configuration of the spacer 221 according to this embodiment. Specifically, FIG. 7(a) is a top view showing the configuration of the spacer 221 shown in FIG. 6 when viewed from the positive direction of the Z axis. FIG. 7(b) is a bottom view showing the configuration of the spacer 221 shown in FIG. 6 when viewed from the negative direction of the Z axis. FIG. 8 is a cross-sectional view showing the configuration of the spacer 221 according to this embodiment. Specifically, (a) of Figure 8 shows a cross-section of the spacer 221 shown in Figure 7 taken along a plane passing through line VIII-VIII and parallel to the YZ plane, and (b) and (c) of Figure 8 show an enlarged view of the configuration within the dashed line in (a) of Figure 8.

[0062] [4.1 Schematic configuration of spacer 221] 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 elements 210 in the Z-axis direction (first direction). Specifically, the spacer main body 260 faces the long side surfaces of the containers 210a of the energy storage elements 210, and is disposed between the long side surfaces of the two energy storage elements 210.

[0063] The spacer body 260 has a planar first surface 260a which is one surface in the Z-axis direction (arrangement direction), and a planar second surface 260b which is the other surface. That is, the first surface 260a is the main surface of the spacer body 260 in the Z-axis positive direction, and the second surface 260b is the main surface of the spacer body 260 in the Z-axis negative direction. First convex portions 261, 262, and 263 are arranged on the first surface 260a, and second convex portions 264, 265, and 266 are arranged on the second surface 260b. A detailed description of the configurations of these first convex portions 261, 262, and 263 and second convex portions 264, 265, and 266 will be given later.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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 columnar (in this embodiment, rectangular cylindrical) protrusion that protrudes in the positive direction of the X-axis and extends in the Z-axis direction, and two spacer protrusions 281 are disposed at both ends of the side wall portion 280a in the Y-axis direction.

[0068] The concave wall portions 282 and 283 are recesses that are U-shaped (inverted C-shaped) when viewed from the Z-axis direction, with the surface facing the negative X-axis direction recessed in a rectangular shape toward the positive X-axis direction, and are arranged to extend in the Z-axis direction. The concave wall portions 282 and 283 have their surfaces facing the positive X-axis direction protruding in the positive X-axis direction, so they can also be said to be bulging convex portions that protrude in a rectangular shape toward the positive X-axis direction and extend in the Z-axis direction when viewed from the Z-axis direction. In this embodiment, two concave wall portions 282 are arranged between two spacer convex portions 281, and two concave wall portions 283 are arranged between the two concave wall portions 282.

[0069] The concave wall portions 284 and 285 are generally C-shaped recesses as viewed from the Z-axis direction, with the surface in 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 have their surfaces in the negative X-axis direction protruding in the negative X-axis direction, so they can also be said to be bulging convex portions extending in the Z-axis direction protruding in a rectangular shape toward the negative X-axis direction as viewed from the Z-axis direction. As a result, the surfaces in the negative X-axis direction of the concave wall portions 284 and 285 abut against the short side surface of the container 210a of the energy storage element 210. 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 walls 285 are disposed between each of the two concave walls 282 and each of the two concave walls 283, respectively.

[0070] The concave walls 282 and 283 are inserted into the side recesses 242 (see FIG. 4) of the side member 240, and the side protrusions 241 (see FIG. 4) of the side member 240 are inserted into the concave walls 284 and 285. The side protrusions 241 are protruding in a rectangular shape on both sides in the X-axis direction of the side member 240 and extending from one end to the other end in the Z-axis direction of the side member 240, and are formed with the above-mentioned openings 243 and 244. The side recesses 242 are recesses that are recessed in a rectangular shape on both sides in the X-axis direction of the side member 240 and extending from one end to the other end in the Z-axis direction of the side member 240.

[0071] 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.

[0072] [4.2 Explanation of the configuration of the first convex portion and the second convex portion of the spacer body 260] Next, the configurations of the first convex portions 261, 262, and 263 and the second convex portions 264, 265, and 266 of the spacer body 260 will be described in detail. The first convex portions 261, 262, and 263 are convex portions formed by protruding from the first surface 260a in the positive direction of the Z axis and extending in the X axis direction along the first surface 260a. The second convex portions 264, 265, and 266 are convex portions formed by protruding from the second surface 260b in the negative direction of the Z axis and extending in the X axis direction along the second surface 260b.

[0073] The first convex portion 261 is a rib that extends linearly from one end to the other end of the first surface 260a in the X-axis direction at the end of the first surface 260a in the Y-axis direction, and one first convex portion 261 is disposed at each of both ends of the first surface 260a in the Y-axis direction. In this embodiment, the first convex portion 261 has a rectangular cross-sectional shape when cut on the YZ plane, but the cross-sectional shape may be any shape, such as a triangular shape, a semicircular shape, or a semi-elliptical shape. In addition, the first convex portion 261 does not extend to the edge of the first surface 260a in the X-axis direction. In other words, the first convex portion 261 does not reach the side wall portion 280 (280a and 280b) and is disposed apart from the side wall portion 280 (280a and 280b). Specifically, the first convex portion 261 is disposed in the X-axis direction of the concave wall portion 284 at both ends in the Y-axis direction of the side wall portion 280 (280a and 280b), and extends toward the concave wall portion 284, but is disposed at a distance from the concave wall portion 284.

[0074] The second convex portion 264 is a rib that extends linearly from one end to the other end of the second surface 260b in the X-axis direction at the end of the second surface 260b in the Y-axis direction, and two second convex portions 264 are arranged at each of both ends of the second surface 260b in the Y-axis direction. In this embodiment, the second convex portion 264 has a rectangular cross-sectional shape when cut on the YZ plane, but the cross-sectional shape may be any shape such as a triangular shape, a semicircular shape, or a semi-elliptical shape. The second convex portion 264 has the same length in the X-axis direction as the first convex portion 261, but the length in the X-axis direction may be different. In addition, the second convex portion 264 does not extend to the edge of the second surface 260b in the X-axis direction. In other words, the second convex portion 264 does not reach the side wall portion 280 (280a and 280b) and is arranged apart from the side wall portion 280 (280a and 280b). Specifically, the second convex portion 264 is disposed in the X-axis direction of the concave wall portion 284 at both ends in the Y-axis direction of the side wall portion 280 (280a and 280b) and extends toward the concave wall portion 284, but is disposed at a distance from the concave wall portion 284.

[0075] The first convex portion 262 is a rib extending linearly in the X-axis direction in the Y-axis direction center of the first surface 260a, and one first convex portion 262 is disposed at each of both ends in the X-axis direction of the first surface 260a. The cross-sectional shape of the first convex portion 262 is similar to that of the first convex portion 261. Like the first convex portion 261, the first convex portion 262 does not extend to the edge of the first surface 260a in the X-axis direction, and is disposed apart from the side wall portion 280 (280a and 280b). Specifically, the first convex portion 262 is disposed in the X-axis direction of a concave wall portion 284 in the Y-axis direction center of the side wall portion 280 (280a and 280b), and extends toward the concave wall portion 284, but is disposed apart from the concave wall portion 284.

[0076] The second convex portion 265 is a rib extending linearly in the X-axis direction in the center of the second surface 260b in the Y-axis direction, and two second convex portions 265 are arranged at each of both ends in the X-axis direction of the second surface 260b. The cross-sectional shape of the second convex portion 265 is similar to that of the second convex portion 264. The second convex portion 265 has the same length in the X-axis direction as the first convex portion 262, but the length in the X-axis direction may be different. Like the second convex portion 264, the second convex portion 265 does not extend to the edge of the second surface 260b in the X-axis direction, and is arranged apart from the side wall portion 280 (280a and 280b). Specifically, the second convex portion 265 is disposed in the X-axis direction of the concave wall portion 284 at the center in the Y-axis direction of the side wall portion 280 (280a and 280b), and extends toward the concave wall portion 284, but is disposed at a distance from the concave wall portion 284.

[0077] The first convex portion 263 is a rib extending linearly in the X-axis direction on both sides of the first convex portion 262 in the Y-axis direction, and two first convex portions 263 are arranged between each of the first convex portions 261 and 262. The cross-sectional shape of the first convex portion 263 is the same as that of the first convex portion 262. Like the first convex portion 262, the first convex portion 263 does not extend to the edge of the first surface 260a in the X-axis direction, and is arranged apart from the side wall portion 280 (280a and 280b). Specifically, the first convex portion 263 is arranged in the X-axis direction of the concave wall portion 285 of the side wall portion 280 (280a and 280b), and extends toward the concave wall portion 285, but is arranged apart from the concave wall portion 285.

[0078] The second convex portion 266 is a rib extending linearly in the X-axis direction on both sides of the second convex portion 265 in the Y-axis direction, and one second convex portion 266 is disposed between each of the second convex portions 264 and 265. The cross-sectional shape of the second convex portion 266 is the same as that of the second convex portion 265. The second convex portion 266 has the same length in the X-axis direction as the first convex portion 263, but the length in the X-axis direction may be different. Like the second convex portion 265, the second convex portion 266 does not extend to the edge of the second surface 260b in the X-axis direction, and is disposed apart from the side wall portion 280 (280a and 280b). Specifically, the second convex portion 266 is disposed in the X-axis direction of the concave wall portion 285 of the side wall portion 280 (280a and 280b), and extends toward the concave wall portion 285, but is disposed apart from the concave wall portion 285.

[0079] In this manner, the first convex portions 261, 262, and 263, and the second convex portions 264, 265, and 266 are arranged to extend in the same direction (X-axis direction). The spacer 221 has a side wall portion 280 (280a and 280b) which is a wall portion facing the energy storage element 210 in the extension direction (X-axis direction) of at least one of the convex portions of the first convex portion 261 etc. and the second convex portion 264 etc. And at least one of the convex portions (all the convex portions in this embodiment) of the first convex portion 261 etc. and the second convex portion 264 etc. is arranged to be spaced apart from the wall portion (side wall portion 280 (280a and 280b)). Specifically, these first convex portions 261 etc. and second convex portions 264 etc. are positioned adjacent to concave wall portions 284 and 285, which are the wall portions of the side wall portion 280 that abut against the energy storage element 210, and are spaced apart from the concave wall portions 284 and 285.

[0080] Also, as viewed from the Z-axis direction (arrangement direction), the second convex portion 264 is disposed in a position adjacent to the first convex portion 261, the second convex portion 265 is disposed in a position adjacent to the first convex portion 262, and the second convex portion 266 is disposed in a position adjacent to the first convex portion 263. In other words, the second convex portions 264, 265, and 266 are disposed in positions that do not overlap with the first convex portions 261, 262, and 263 as viewed from the Z-axis direction (positions that do not face each other in the Z-axis direction). In this embodiment, as viewed from the Z-axis direction (arrangement direction), one first convex portion 261 is disposed between two second convex portions 264, one first convex portion 262 is disposed between two second convex portions 265, and one second convex portion 266 is disposed between two first convex portions 263. As a result, the multiple first convex portions 261, 262, and 263 and the multiple second convex portions 264, 265, and 266 are alternately arranged when viewed from the Z-axis direction (arrangement direction). Note that, although an enlarged view of the cross-sectional shapes of the first convex portion 262 and the second convex portion 265 is not shown in Fig. 8, they have the same shape as the cross-sectional shapes of the first convex portion 261 and the second convex portion 264 shown in Fig. 8(b).

[0081] [5. Description of Effects] As described above, according to the energy storage device 10 of the embodiment of the present invention, the spacer 221 is disposed on the first surface 260a and has the first convex portions 261, 262, and 263 (hereinafter also referred to as the first convex portion 261, etc.) extending along the first surface 260a. The spacer 221 also has the second convex portions 264, 265, and 266 (hereinafter also referred to as the second convex portion 264, etc.) disposed on the second surface 260b and adjacent to the first convex portion 261, etc. as viewed from the arrangement direction (Z-axis direction). Here, if the elongated first convex portion 261, etc. is disposed on the first surface 260a of the spacer 221, stress is concentrated over the elongated first convex portion 261, etc., and the spacer 221 may be damaged. Furthermore, if the second convex portions 264, etc. are arranged at positions overlapping the first convex portions 261, etc., as viewed from the arrangement direction on the second surface 260b of the spacer 221, the stress is concentrated on the first convex portions 261, etc. and the second convex portions 264, etc., and the risk of the spacer 221 being damaged increases. For this reason, on the second surface 260b of the spacer 221, the second convex portions 264, etc. are arranged at positions adjacent to the first convex portions 261, etc. (positions not overlapping the first convex portions 261, etc.) as viewed from the arrangement direction. This distributes the stress applied to the first convex portions 261, etc. and the second convex portions 264, etc., and can suppress the concentration of the stress on the first convex portions 261, etc. and the second convex portions 264, etc. Therefore, damage to the spacer 221 can be suppressed.

[0082] In addition, by providing the first convex portions 261 etc. of the first surface 260a and the second convex portions 264 etc. of the second surface 260b extending in the same direction, stress is easily dispersed to the first convex portions 261 etc. and the second convex portions 264 etc. that are arranged in adjacent positions. This makes it possible to prevent stress from concentrating on the first convex portions 261 etc. and the second convex portions 264 etc., and therefore makes it possible to prevent damage to the spacer 221.

[0083] Moreover, by arranging the second convex portion 266 of the second surface 260b between the two first convex portions 263 of the first surface 260a when viewed from the arrangement direction (Z-axis direction), stress is easily dispersed to the first convex portion 263 and the second convex portion 266. This makes it possible to suppress stress concentration on the first convex portion 263 and the second convex portion 266, thereby suppressing damage to the spacer 221. The same can be said about the first convex portion 261 and the two second convex portions 264, and the first convex portion 262 and the two second convex portions 265.

[0084] Furthermore, the multiple first convex portions 261 etc. of the first surface 260a and the multiple second convex portions 264 etc. of the second surface 260b are alternately arranged when viewed from the arrangement direction (Z-axis direction), which makes it easy to distribute stress to the first convex portions 261 etc. and the second convex portions 264 etc. This makes it possible to suppress concentration of stress on the first convex portions 261 etc. and the second convex portions 264 etc., thereby making it possible to suppress damage to the spacer 221.

[0085] In addition, at least one of the convex portions, such as the first convex portion 261 etc. of the first surface 260a and the second convex portion 264 etc. of the second surface 260b, is disposed away from the wall portion (side wall portion 280) facing the energy storage element 210, so that the at least one of the convex portions is easily deformed. In particular, the concave wall portions 284 and 285 of the side wall portion 280 are in contact with the energy storage element 210 and their movement is restricted, so that if at least one of the convex portions, such as the first convex portion 261 etc. and the second convex portion 264 etc., is extended to the concave wall portions 284, 285, the at least one of the convex portions is less likely to deform. Therefore, at least one of the convex portions, such as the first convex portion 261 etc. and the second convex portion 264 etc., is disposed away from the concave wall portions 284, 285, so that the at least one of the convex portions is easily deformed. This makes it possible to suppress stress concentration on the at least one of the convex portions, and therefore to suppress damage to the spacer 221.

[0086] [6 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.

[0087] 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 the spacer 222 is not arranged may be used. When the spacer 221 is not arranged, the spacer 222 can perform the same function as the spacer 221 by having the same configuration of the first convex portion and the second convex portion as the spacer 221 described above.

[0088] In the above embodiment, the first convex portion 261 etc. and the second convex portion 264 etc. of the spacer 221 are linearly extended in the X-axis direction. However, at least one of these convex portions may be extended in a direction different from the X-axis direction, such as a direction inclined from the X-axis direction or the Y-axis direction. For example, the first convex portion 261 and the second convex portion 264 may be extended in different directions. At least one of the first convex portion 261 etc. and the second convex portion 264 etc. may be extended in a curved shape rather than a linear shape. The second convex portion 264 etc. is an elongated convex portion, but at least one of the second convex portions 264 etc. may not be elongated.

[0089] In the above embodiment, the first convex portion 261 etc. are arranged on the first surface 260a of the spacer 221, and the second convex portion 264 etc. are arranged on the second surface 260b. However, the second convex portion 264 etc. may be arranged on the first surface 260a, and the first convex portion 261 etc. may be arranged on the second surface 260b.

[0090] In the above embodiment, the first convex portions 261 etc. and the second convex portions 264 etc. of the spacer 221 are arranged alternately when viewed from the Z-axis direction. However, the first convex portions 261 etc. and the second convex portions 264 etc. may be arranged in any order when viewed from the Z-axis direction. For example, the first convex portion 261 may be arranged on the side of the two second convex portions 264, not between the two second convex portions 264. Also, only one second convex portion 264 may be arranged, and the first convex portion 261 may be arranged at a position adjacent to the one second convex portion 264. The same applies to the first convex portion 262 and the second convex portion 265, and the first convex portion 263 and the second convex portion 266.

[0091] In the above embodiment, the first convex portions 261 etc. and the second convex portions 264 etc. of the spacer 221 are arranged apart from the side wall portion 280. However, at least one of the first convex portions 261 etc. and the second convex portions 264 etc. may be extended to the side wall portion 280 and reach the side wall portion 280.

[0092] In the above embodiment, the spacer 221 has a plurality of first convex portions and a plurality of second convex portions. However, it is sufficient that the spacer 221 has at least one first convex portion and at least one second convex portion arranged in adjacent positions.

[0093] In the above embodiment, the spacer 221 has the front wall portion 270, the pair of side wall portions 280, and the rear wall portion 290. However, the spacer 221 does not necessarily have to have at least one of the front wall portion 270, the pair of side wall portions 280, and the rear wall portion 290.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] The present invention can be realized not only as the power storage device 10 but also as the spacer 221. [Industrial Applicability]

[0099] 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]

[0100] 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 Side protrusion 242 Side recess 250 Busbar 260 Spacer body 260a Front page 260b second side 261, 262, 263 First convex part 264, 265, 266 Second convex part 270 Front wall 281 Spacer protrusion 282, 283, 284, 285 Concave wall 290 Rear wall 300 Electrical Equipment Units

Claims

1. An energy storage device including energy storage elements and spacers arranged in an arrangement direction, The spacer is a spacer body having a planar first surface which is one surface in the arrangement direction and a planar second surface which is the other surface; A first protrusion disposed on the first surface and extending along the first surface; a second convex portion disposed on the second surface, the second convex portion being disposed at a position adjacent to the first convex portion when viewed from the arrangement direction, the spacer has a wall portion facing the energy storage element in an extension direction of at least one of the first convex portion and the second convex portion, The at least one protruding portion is disposed apart from the wall portion. Energy storage device.

2. An energy storage device including energy storage elements and spacers arranged in an arrangement direction, The spacer is a spacer body having a planar first surface which is one surface in the arrangement direction and a planar second surface which is the other surface; A first protrusion disposed on the first surface and extending along the first surface; a second convex portion disposed on the second surface, the second convex portion being disposed at a position adjacent to the first convex portion when viewed from the arrangement direction, the spacer has a wall portion facing the energy storage element in an extension direction of at least one of the first convex portion and the second convex portion, The at least one protruding portion is disposed in contact with the wall portion. Energy storage device.

3. The first convex portion and the second convex portion are disposed to extend in the same direction. The power storage device according to claim 1 or 2.

4. The spacer has two of the first protrusions, The second convex portion is disposed between two of the first convex portions when viewed from the arrangement direction. The power storage device according to any one of claims 1 to 3.

5. the spacer has a plurality of the first convex portions and a plurality of the second convex portions, The first convex portions and the second convex portions are alternately arranged when viewed from the arrangement direction. The power storage device according to any one of claims 1 to 4.

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