Power storage device

Abstract

A power storage device 10 which is provided with a power storage unit 12 that comprises a first power storage element 301 and a second power storage element 302, said power storage elements being arranged in a first direction, wherein: the first power storage element 301 has a surface (a long lateral surface part 311) that faces the second power storage element 302, said surface being provided with a recessed part 311a; and the power storage unit 12 additionally comprises a first adhesive body 710 that is arranged in the recessed part 311a between the first power storage element 301 and the second power storage element 302 so as to bond the first power storage element 301 and the second power storage element 302 to each other, and a spacer 600 that is arranged at a position that is different from the position of the first adhesive body 710 in a second direction that intersects with the first direction between the first power storage element 301 and the second power storage element 302.

Description

[Technical Field]

[0001] The present invention relates to an energy storage device including a plurality of energy storage elements. [Background technology]

[0002] Conventionally, a power storage device configured with a plurality of power storage elements arranged side by side has been widely known. For example, Patent Document 1 discloses a secondary battery device (power storage device) in which a plurality of battery cells (power storage elements) are arranged and bonded with an adhesive or the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-251241 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described conventionally configured power storage devices, it may not be possible to improve the vibration resistance or impact resistance. For example, in the above-described Patent Document 1, multiple power storage elements (battery cells) are bonded via a lower case with an adhesive. However, in general, in order to reduce the size of the power storage device, it is desirable to reduce the distance between the power storage elements, which results in a thin adhesive between the power storage elements. As a result, the adhesive strength between the power storage elements is insufficient, and the power storage elements cannot be firmly bonded together, which may prevent the vibration resistance or impact resistance of the power storage device from being improved.

[0005] The present invention was made by the inventors of the present application by focusing on the above-mentioned problem, and an object of the present invention is to provide an electricity storage device that can improve vibration resistance or impact resistance. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, one embodiment of the present invention provides an energy storage device comprising an energy storage unit having a first energy storage element and a second energy storage element aligned in a first direction, wherein the first energy storage element has a recessed surface facing the second energy storage element, and the energy storage unit further comprises a first adhesive disposed within the recess and adhering the first energy storage element and the second energy storage element together, and a spacer disposed between the first energy storage element and the second energy storage element, the spacer being disposed at a different position from the first adhesive in a second direction intersecting the first direction.

[0007] According to this, in the energy storage device, the energy storage unit includes a first adhesive body disposed between the first energy storage element and the second energy storage element in a recess formed on the surface of the first energy storage element facing the second energy storage element, and a spacer disposed at a position different from the first adhesive body. By disposing the first adhesive body in the recess of the first energy storage element, the thickness of the first adhesive body can be increased, and by disposing the spacer at a position different from the first adhesive body, the thickness of the first adhesive body can be further increased. In particular, by disposing the spacer between the first energy storage element and the second energy storage element, the first adhesive body can be prevented from being compressed and becoming thinner, and the thickness of the first adhesive body can be maintained at a high level. This increases the adhesive strength between the first energy storage element and the second energy storage element, thereby improving the vibration resistance or impact resistance of the energy storage device. [Effects of the Invention]

[0008] According to the electricity storage device of the present invention, it is possible to improve vibration resistance or shock resistance. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing the appearance of a power storage device according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view showing each component of the electricity storage device according to the embodiment. [Figure 3] FIG. 3 is a perspective view showing the configuration of the energy storage element according to the embodiment. [Figure 4] FIG. 4 is a perspective view and a cross-sectional view showing a recess formed in a container of an energy storage device according to an embodiment. [Figure 5] FIG. 5 is a front view showing a configuration in which a spacer and a first adhesive body are arranged on an energy storage device according to the embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a structure of bonding of energy storage elements in an energy storage unit and bonding of energy storage units in an exterior body according to the embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a structure of bonding energy storage elements in an energy storage unit and bonding energy storage units in an exterior body according to the embodiment. [Figure 8] FIG. 8 is a front view showing a configuration in which a spacer and a first adhesive body are arranged on an energy storage device according to a first modification of the embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing a configuration of a first adhesive body according to the second modification of the embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing a configuration of a first adhesive body according to the third modification of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] A storage device according to one embodiment of the present invention is a storage device comprising a storage unit having a first storage element and a second storage element aligned in a first direction, wherein the first storage element has a recess in the surface facing the second storage element, and the storage unit further comprises a first adhesive disposed within the recess and adhering the first storage element and the second storage element together, and a spacer disposed between the first storage element and the second storage element, the spacer being disposed at a different position from the first adhesive in a second direction intersecting the first direction.

[0011] According to this, in the energy storage device, the energy storage unit includes a first adhesive body disposed between the first energy storage element and the second energy storage element in a recess formed on the surface of the first energy storage element facing the second energy storage element, and a spacer disposed at a position different from the first adhesive body. By disposing the first adhesive body in the recess of the first energy storage element, the thickness of the first adhesive body can be increased, and by disposing the spacer at a position different from the first adhesive body, the thickness of the first adhesive body can be further increased. In particular, by disposing the spacer between the first energy storage element and the second energy storage element, the first adhesive body can be prevented from being compressed and becoming thinner, and the thickness of the first adhesive body can be maintained at a high level. This increases the adhesive strength between the first energy storage element and the second energy storage element, thereby improving the vibration resistance or impact resistance of the energy storage device.

[0012] The spacer may have an adhesive layer on both sides in the first direction, the adhesive layer being bonded to the first storage element or the second storage element.

[0013] According to this, the spacer has adhesive layers on both sides that are bonded to the first and second energy storage elements. By bonding the spacer to the first and second energy storage elements in this way, the first and second energy storage elements are fixed via the spacer. This allows the first and second energy storage elements to be more firmly fixed by the adhesion via the first adhesive and the adhesion via the spacer, thereby improving the vibration resistance or impact resistance of the energy storage device.

[0014] The recess may be formed by recessing a central portion of the surface of the first storage element in the second direction.

[0015] According to this, the first adhesive body is disposed in a recess formed in the center of the surface of the first energy storage element that faces the second energy storage element. By disposing the first adhesive body in the recess in the center of the first energy storage element, the first energy storage element and the second energy storage element can be bonded in a balanced manner, thereby improving the vibration resistance or impact resistance of the energy storage device.

[0016] The energy storage unit may further include an end member arranged in a position in the first direction so as to sandwich the first energy storage element between the end member and the second energy storage element, and a second adhesive arranged between the end member and the first energy storage element and adhering the end member and the first energy storage element.

[0017] According to this, the energy storage unit has an end member and a second adhesive that adheres the end member and the first energy storage element. By adhering the end member and the first energy storage element with the second adhesive in this way, movement of the first energy storage element relative to the end member can be suppressed, thereby improving the vibration resistance or impact resistance of the energy storage device.

[0018] The power storage device may further include an exterior body that houses the power storage unit, and a fixing member that fixes the power storage unit and the exterior body.

[0019] According to this, a fixing member is provided to fix the energy storage unit and the exterior body. By fixing the energy storage unit and the exterior body with the fixing member in this way, movement of the energy storage unit (the first energy storage element and the second energy storage element) within the exterior body can be suppressed, thereby improving the vibration resistance or impact resistance of the energy storage device.

[0020] The first adhesive body may have a heat insulating material therein.

[0021] According to this, since the first adhesive body has the insulating material inside, the insulating material can be fixed together with the first storage element and the second storage element, thereby improving the vibration resistance or impact resistance of the storage device even when the insulating material is disposed between the first storage element and the second storage element.

[0022] Hereinafter, with reference to the drawings, a description will be given of an energy storage device according to an embodiment of the present invention (including its modified examples). The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, manufacturing processes, and the order of manufacturing processes shown in the following embodiments are merely examples and are not intended to limit the present invention. In each drawing, dimensions and the like are not strictly illustrated. In each drawing, the same or similar components are designated by the same reference numerals.

[0023] In the following description and drawings, the X-axis direction is defined as the arrangement direction of multiple energy storage elements, the arrangement direction of a pair of end members, the arrangement direction of the energy storage elements and the end members, the opposing direction of a pair of long side surfaces of a container for one energy storage element, or the thickness direction of the energy storage element or the end member. The Y-axis direction is defined as the arrangement direction of a pair of electrode terminals of one energy storage element, or the opposing direction of a pair of short side surfaces of a container for one energy storage element. The Z-axis direction is defined as the arrangement direction of the exterior body and exterior body lid of the energy storage device, the arrangement direction of the container body and container lid of one energy storage element, the arrangement direction of the energy storage element and the bus bar, or the up-down direction. The X-axis direction, Y-axis direction, and Z-axis direction intersect each other (orthogonal in this embodiment). Depending on the usage mode, the Z-axis direction may not be the up-down direction; however, for convenience of explanation, the Z-axis direction will be described below as the up-down direction.

[0024] In the following description, the positive X-axis direction refers to the direction of the X-axis arrow, and the negative X-axis direction refers to the direction opposite to the positive X-axis direction. The same applies to the Y-axis and Z-axis directions. In the following, the X-axis direction may also be referred to as the first direction, and a direction intersecting the first direction (such as the Y-axis or Z-axis direction perpendicular to the X-axis) may also be referred to as the second direction. Expressions indicating relative directions or attitudes, such as parallel and perpendicular, may also include cases where the directions or attitudes are not strictly those of the same kind. For example, saying that two directions are perpendicular does not only mean that the two directions are completely perpendicular, but also means that the directions are substantially perpendicular, i.e., there may be a difference of, for example, a few percent.

[0025] (Embodiment) [1 General Description of the Power Storage Device 10] First, the configuration of the electricity storage device 10 will be described. Fig. 1 is a perspective view showing the appearance of the electricity storage device 10 according to the present embodiment. Fig. 2 is an exploded perspective view showing each component of the electricity storage device 10 according to the present embodiment.

[0026] The power storage device 10 is a device capable of charging with electricity from an external source and discharging electricity to the external source, and in this embodiment, has a substantially rectangular parallelepiped shape. For example, the power storage device 10 is a battery module (battery assembly) used for power storage or power supply purposes. Specifically, the power storage device 10 is used as a battery for driving or starting the engine of a mobile object such as an automobile, motorcycle, personal watercraft, ship, snowmobile, agricultural machinery, construction machinery, or electric railway vehicle. Examples of the automobile include an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a gasoline-powered vehicle. Examples of the electric railway vehicle 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 or business use.

[0027] As shown in Fig. 1, the energy storage device 10 includes an exterior body 11. As shown in Fig. 2, an energy storage unit 12 including a plurality of energy storage elements 300, a pair of end members 400, and a plurality of bus bars 500 is housed inside the exterior body 11. In addition to the above components, the energy storage device 10 (energy storage unit 12) may also include a bus bar frame for positioning the bus bars 500, a circuit board for monitoring the charge state and discharge state of the energy storage elements 300, and electrical equipment such as a relay.

[0028] The exterior body 11 is a box-shaped (approximately rectangular parallelepiped) container (module case) that forms the housing (outer shell) of the energy storage device 10. The exterior body 11 is arranged on the outside of the plurality of energy storage elements 300, the pair of end members 400, and the plurality of bus bars 500, and fixes the energy storage elements 300 and other components in predetermined positions to protect them from impacts and the like. The exterior body 11 is formed from an insulating material such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), 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), polyethersulfone (PES), ABS resin, or a composite material thereof. This prevents the energy storage elements 300 and the like from coming into contact with external metal members, etc. The exterior body 11 may be formed of a conductive member such as a metal, as long as the electrical insulation of the energy storage elements 300 and the like is maintained.

[0029] The exterior body 11 has an exterior body main body 100 that constitutes the main body of the exterior body 11, and an exterior body lid body 200 that constitutes the lid body of the exterior body 11. The exterior body main body 100 is a bottomed rectangular cylindrical housing (chassis) with an opening facing in the positive direction of the Z axis, and houses the energy storage device 300 and the like. The exterior body main body 100 has a pair of opposing short side walls 110 on both side surfaces in the X axis direction, a pair of opposing long side walls 120 on both side surfaces in the Y axis direction, and a bottom wall 130 on the negative Z axis side. Depending on the number and shape of the energy storage devices 300, the exterior body main body 100 may have a pair of long side walls on both side surfaces in the X axis direction and a pair of short side walls on both side surfaces in the Y axis direction.

[0030] The short side wall portion 110 is a rectangular, flat wall portion that forms the short side surface of the exterior body 11, and is arranged opposite the end member 400 in the X-axis direction. The short side wall portion 110 is adjacent to the long side wall portion 120 and the bottom wall portion 130. The short side wall portion 110 is a wall portion that has a smaller outer surface area than the long side wall portion 120. The long side wall portion 120 is a rectangular, flat wall portion that forms the long side surface of the exterior body 11, and is arranged opposite a short side surface portion 312 of a container 310 (described later) of the energy storage element 300 in the Y-axis direction. The long side wall portion 120 is adjacent to the short side wall portion 110 and the bottom wall portion 130. The long side wall portion 120 is a wall portion that has a larger outer surface area than the short side wall portion 110. The bottom wall portion 130 is a rectangular, flat wall portion that forms the bottom surface of the exterior body 11, and is arranged opposite to a bottom surface portion 313 of a container 310 (described later) of the energy storage element 300 in the Z-axis direction. The bottom wall portion 130 is a wall portion that is adjacent to the short side wall portion 110 and the long side wall portion 120.

[0031] The exterior body lid 200 is a flat, rectangular member that is joined to the exterior body main body 100 by heat sealing or the like, thereby closing the opening of the exterior body main body 100. The exterior body lid 200 is provided with a pair of positive and negative external terminals 210 (a positive electrode external terminal and a negative electrode external terminal). The energy storage device 10 charges with electricity from the outside and discharges electricity to the outside via this pair of external terminals 210. The exterior body main body 100 and the exterior body lid 200 may be made of the same material or different materials.

[0032] The energy storage element 300 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. In this embodiment, the energy storage element 300 has a flattened rectangular parallelepiped (rectangular) shape, and eight energy storage elements 300 are arranged side by side in the X-axis direction (first direction). The shape of the energy storage elements 300 is not limited to a rectangular parallelepiped shape and may be an elongated cylindrical shape or a polygonal prism shape other than a rectangular parallelepiped. The number of the arranged energy storage elements 300 is not particularly limited as long as it is two or more. The energy storage element 300 is not limited to a non-aqueous electrolyte secondary battery and may be a secondary battery other than a non-aqueous electrolyte secondary battery or a capacitor. The energy storage element 300 may not be a secondary battery but may be a primary battery that allows stored electricity to be used without the user having to charge it. The energy storage element 300 may be a battery using a solid electrolyte. The energy storage element 300 may be a pouch-type energy storage element. The configuration of the energy storage element 300 will be described in detail later.

[0033] The end members 400 are flat, rectangular members (sandwiching members) arranged on both sides of the plurality of energy storage elements 300 in the X-axis direction and sandwich and hold the plurality of energy storage elements 300 from both sides in the arrangement direction (X-axis direction) of the plurality of energy storage elements 300. As a result, the pair of end members 400 compress the plurality of energy storage elements 300 from both sides in the arrangement direction (X-axis direction). From the viewpoint of ensuring strength, the end members 400 are formed from a metallic (conductive) material such as stainless steel, iron, plated steel sheet, aluminum, or aluminum alloy. The material of the end members 400 is not particularly limited, and may be formed from, for example, a high-strength, electrically insulating material or may be subjected to an insulating treatment. The shape of the end members 400 is also not particularly limited, and may be a plate-like member having irregularities (such as a corrugated plate), a block-like member, or the like.

[0034] The bus bar 500 is a rectangular, flat member disposed above the plurality of energy storage elements 300 and connected to electrode terminals 340 (positive and negative terminals, described later) of the plurality of energy storage elements 300. As a result, the bus bar 500 connects the electrode terminals 340 of the plurality of energy storage elements 300 to each other, and also connects the electrode terminals 340 of the end energy storage elements 300 to the external terminals 210 via other bus bars (not shown). The bus bar 500 is formed of a conductive member made of metal such as aluminum, an aluminum alloy, copper, or a copper alloy. In this embodiment, the bus bar 500 connects two energy storage elements 300 in parallel to form four sets of energy storage element groups, and the four sets of energy storage element groups are connected in series; however, the connection form of the energy storage elements 300 is not particularly limited.

[0035] [2. Description of the Energy Storage Element 300] A detailed description will be given of the configuration of the energy storage element 300. Since all of the energy storage elements 300 included in the energy storage unit 12 have the same configuration, the configuration of one energy storage element 300 will be described in detail below.

[0036] FIG. 3 is a perspective view showing the configuration of an energy storage device 300 according to this embodiment. Specifically, FIG. 3 shows the internal configuration of the container 310 of the energy storage device 300, seen through the container 310. FIG. 4 shows a perspective view and a cross-sectional view showing a recess 311a formed in the container 310 of the energy storage device 300 according to this embodiment. Specifically, (a) of FIG. 4 is a perspective view showing the appearance of the container 310. (b) of FIG. 4 is a cross-sectional view showing the configuration when (a) of FIG. 4 is cut along line IVb-IVb, that is, a cross-sectional view showing the configuration when cut along a plane passing through the center of the container 310 and parallel to the XZ plane. (c) of FIG. 4 is a cross-sectional view showing the configuration when (a) of FIG. 4 is cut along line IVc-IVc, that is, a cross-sectional view showing the configuration when cut along a plane passing through the center of the container 310 and parallel to the XY plane.

[0037] 3, the energy storage element 300 includes a container 310 and a pair of electrode terminals 340 (positive and negative electrodes), and the container 310 contains an electrode assembly 350 and a pair of current collectors 360 (positive and negative electrodes). An electrolyte (non-aqueous electrolyte) is sealed inside the container 310, and gaskets are disposed between the electrode terminals 340 and current collectors 360 and the container 310 (container lid 330, which will be described later), but detailed description of these will be omitted. There are no particular limitations on the type of electrolyte, and various types can be selected as long as they do not impair the performance of the energy storage element 300.

[0038] In addition to the above components, the energy storage element 300 may have spacers arranged on the sides or below the electrode assembly 350, an insulating film that wraps around the electrode assembly 350, etc. An insulating film (shrink tube, etc.) that covers the outer surface of the container 310 may be arranged around the container 310. The material of the insulating film is not particularly limited as long as it can ensure the electrical insulation required for the energy storage element 300, and examples of the material include electrically insulating resins such as PC, PP, PE, PPS, PET, PBT, and ABS resin, epoxy resin, Kapton, Teflon (registered trademark), silicone, polyisoprene, and polyvinyl chloride.

[0039] The container 310 is a rectangular parallelepiped (square or box-shaped) case having a container body 320 with an opening formed therein and a container lid 330 that closes the opening of the container body 320. The container body 320 is a rectangular cylindrical member with a bottom that forms the main body of the container 310, and has an opening formed on the positive side of the Z axis. The container lid 330 is a rectangular plate-like member that forms the lid of the container 310, and is disposed on the positive side of the Z axis of the container body 320, extending in the Y axis direction. The container lid 330 is provided with a gas exhaust valve that releases pressure inside the container 310 when the pressure inside the container 310 increases, a liquid injection part (not shown) for injecting the electrolyte into the container 310, and the like. The material of the container 310 (the container body 320 and the container lid 330) is not particularly limited and can be, for example, a weldable (joinable) metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel sheet, but resin can also be used.

[0040] After the electrode assembly 350 and the like are housed inside the container body 320, the container body 320 and the container lid 330 are joined by welding or the like to form a joint 310a, thereby sealing the interior of the container 310. The container 310 has a pair of long side surfaces 311 on both sides in the X-axis direction, a pair of short side surfaces 312 on both sides in the Y-axis direction, and a bottom surface 313 on the negative Z-axis side.

[0041] The long side surface portion 311 is a rectangular flat portion that forms the long side of the container 310, and is arranged opposite the long side surface portion 311 of the container 310 of an adjacent energy storage element 300 or the end member 400 in the X-axis direction. The long side surface portion 311 is adjacent to the short side surface portion 312 and the bottom surface portion 313, and has a larger area than the short side surface portion 312. The short side surface portion 312 is a rectangular flat portion that forms the short side of the container 310, and is arranged opposite the long side wall portion 120 of the exterior body 11 in the Y-axis direction. The short side surface portion 312 is adjacent to the long side surface portion 311 and the bottom surface portion 313, and has a smaller area than the long side surface portion 311. The bottom surface portion 313 is a rectangular flat portion that forms the bottom surface of the container 310, and is arranged opposite the bottom wall portion 130 of the exterior body 11 in the Z-axis direction and adjacent to the long side surface portion 311 and the short side surface portion 312.

[0042] A recess 311a is formed in the long side surface portion 311 of the container 310. In this embodiment, the recess 311a is formed in each of the pair of long side surface portions 311 of the container 310. As shown in Fig. 4, the recess 311a is a recess in which the long side surface portion 311 is curvedly recessed in the X-axis direction toward the inside of the container 310. The container 310 gradually recesses in the X-axis direction from the ends of the long side surface portion 311 in the Y-axis and Z-axis directions (the outer peripheral portions of the long side surface portion 311 when viewed from the X-axis direction) toward the center of the long side surface portion 311, so that the center portion of the long side surface portion 311 (more specifically, the center position) has the most recessed shape.

[0043] As described above, the recess 311a is formed by recessing the central portion of the long side surface 311 of the energy storage element 300 in a direction intersecting (perpendicular to) the X-axis direction. The recess depth (depth in the X-axis direction) of the recess 311a at the central portion of the long side surface 311 (the center position of the long side surface 311) is not particularly limited, but is preferably approximately 0.5 mm to 1.5 mm, and more preferably approximately 1 mm. As an example, the recess 311a can be formed by the following method. When an electrolyte solution is poured into the container 310, air may remain in the gaps of the electrode assembly 350, making it difficult for the electrolyte solution to penetrate the electrode assembly 350. In particular, air is likely to remain in the gaps of the electrode assembly 350 in large energy storage elements 300. To remove the air remaining in the container 310, CO2 substitution is performed during the manufacturing of the energy storage element 300. Thereafter, by charging and discharging the energy storage element 300, the replaced CO2 is absorbed by the negative electrode, creating a negative pressure inside the container 310. When the pressure inside the container 310 becomes negative, the long side surface 311 of the container 310 becomes depressed, and a recess 311a can be formed.

[0044] The electrode terminals 340 are terminal members (positive and negative terminals) of the energy storage element 300 that are placed on the container lid 330, and are electrically connected to the positive and negative electrode plates of the electrode assembly 350 via the current collector 360. The electrode terminals 340 are metal members that lead out the electricity stored in the electrode assembly 350 to the external space of the energy storage element 300 and also introduce electricity into the internal space of the energy storage element 300 to store electricity in the electrode assembly 350. The electrode terminals 340 are made of aluminum, an aluminum alloy, copper, a copper alloy, or the like.

[0045] The electrode assembly 350 is an electricity storage element (power generation element) capable of storing electricity, and includes a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate is an electrode plate in which a positive electrode active material layer is formed on a positive electrode substrate layer, which is a strip-shaped current collector foil made of a metal such as aluminum or an aluminum alloy. The negative electrode plate is an electrode plate in which a negative electrode active material layer is formed on a negative electrode substrate layer, which is a strip-shaped current collector foil made of a metal such as copper or a copper alloy. The separator is a microporous resin sheet. The positive electrode active material used in the positive electrode active material layer and the negative electrode active material used in the negative electrode active material layer can be any known material as long as it is capable of absorbing and releasing lithium ions. The separator can also be any known material as long as it does not impair the performance of the energy storage element 300.

[0046] In this embodiment, the electrode assembly 350 is a wound electrode assembly formed by winding layers of positive and negative electrode plates with a separator sandwiched between them. Specifically, the electrode assembly 350 is formed by winding a positive electrode plate and a negative electrode plate, with the separator interposed between them, so that the positive and negative electrode plates are offset from each other in the direction of the winding axis (Y-axis direction). The positive and negative electrode plates have, at their offset ends 351, portions (composite layer-free portions) where the composite material is not applied and the base layer is exposed (no composite material layer is formed). The electrode assembly 350 is electrically and mechanically connected to the current collector 360 at the end 351. The electrode assembly 350 may be formed by winding a positive electrode plate, a negative electrode plate, and a separator around a winding axis parallel to the Z-axis direction. Furthermore, the electrode body 350 may be an electrode body of any type, such as a laminated (stacked) electrode body formed by stacking multiple flat electrode plates, or a bellows-type electrode body in which electrode plates are folded in a bellows shape.

[0047] The current collector 360 is disposed between the electrode assembly 350 and the side wall of the container 310, and is a conductive and rigid member electrically connected to the electrode terminal 340 and the electrode assembly 350. The current collector 360 is joined to the end 351 of the electrode assembly 350 by welding or the like. The positive electrode current collector 360 is made of aluminum, an aluminum alloy, or the like, similar to the positive electrode substrate layer of the positive electrode plate of the electrode assembly 350. The negative electrode current collector 360 is made of copper, a copper alloy, or the like, similar to the negative electrode substrate layer of the negative electrode plate of the electrode assembly 350.

[0048] In the above-described configuration, within the exterior body 11, the energy storage elements 300 are adhered to adjacent members (other energy storage elements 300 or end member 400), and the energy storage unit 12 is adhered to adjacent members (exterior body main body 100). Specifically, adhesives are disposed between adjacent energy storage elements 300 of the multiple energy storage elements 300 included in the energy storage unit 12 and between an end energy storage element 300 and the end member 400, thereby adhering and fixing the multiple energy storage elements 300 and the end member 400. In addition, the energy storage unit 12 is adhered and fixed to the pair of short side wall portions 110, the pair of long side wall portions 120, and the bottom wall portion 130 of the exterior body main body 100. These configurations will be described in detail below.

[0049] [3. Description of Adhesion Structure of Energy Storage Element 300 and Energy Storage Unit 12 in Exterior Body 11] FIG. 5 is a front view showing a configuration in which a spacer 600 and a first adhesive body 710 are arranged on an energy storage device 300 according to the present embodiment. Specifically, FIG. 5 shows the positions of the spacer 600 and the first adhesive body 710 when the state in which the spacer 600 and the first adhesive body 710 are arranged on the energy storage device 300 is viewed from the positive direction of the X axis. FIGS. 6 and 7 are cross-sectional views showing the configuration in which the energy storage device 300 is attached to the energy storage unit 12 and the energy storage unit 12 is attached to the exterior housing 11 according to the present embodiment. Specifically, FIG. 6 is a cross-sectional view showing the configuration in which the energy storage unit 12 is arranged in the exterior housing main body 100 of the exterior housing 11, cut along a plane passing through the center position of the energy storage unit 12 and parallel to the XZ plane. FIG. 7 is a cross-sectional view showing the configuration in which the energy storage unit 12 is arranged in the exterior housing main body 100, cut along a plane passing through the center position of the energy storage unit 12 and parallel to the XY plane.

[0050] 5 to 7, in addition to the above configuration, the energy storage unit 12 has a spacer 600 and a first adhesive body 710. As shown in Fig. 6 and Fig. 7, the spacer 600 and the first adhesive body 710 are arranged between the long side surface portions 311 of two adjacent energy storage elements 300, at positions on the long side surface portions 311 of the energy storage elements 300 shown in Fig. 5.

[0051] 6 and 7 , the storage element 300 located at the end in the negative X-axis direction among the multiple storage elements 300 is also referred to as a first storage element 301, and the storage element 300 adjacent to the first storage element 301 in the positive X-axis direction is also referred to as a second storage element 302. In other words, the storage unit 12 has the first storage element 301 and the second storage element 302 arranged side by side in the X-axis direction (first direction). Since the other storage elements 300 have the same configuration as the first storage element 301 and the second storage element 302, the following description will mainly focus on the first storage element 301 and the second storage element 302, and descriptions of the other storage elements 300 will be simplified or omitted.

[0052] As described above, first energy storage element 301 has recessed recess 311a in long side surface portion 311, which is a surface facing second energy storage element 302. Recess 311a in first energy storage element 301 is a recess formed by recessing a central portion of long side surface portion 311 of first energy storage element 301 in a direction intersecting (orthogonal in the present embodiment) the X-axis direction (second direction: Z-axis direction in FIG. 6 and Y-axis direction in FIG. 7). Similarly, second energy storage element 302 has recessed recess 311a in long side surface portion 311, which is a surface facing first energy storage element 301. Recess 311a in second energy storage element 302 is a recess formed by recessing a central portion of long side surface portion 311 of second energy storage element 302 in a direction intersecting (orthogonal in the present embodiment) the X-axis direction (second direction: Z-axis direction in FIG. 6 and Y-axis direction in FIG. 7).

[0053] In this configuration, spacer 600 and first adhesive body 710 are disposed between first energy storage element 301 and second energy storage element 302. Specifically, spacer 600 and first adhesive body 710 are disposed between long side surface portion 311 of first energy storage element 301 and long side surface portion 311 of second energy storage element 302.

[0054] The spacer 600 is a member that is disposed between the first energy storage element 301 and the second energy storage element 302 at a position different from the first adhesive body 710 in a direction (second direction) that intersects (is orthogonal in the present embodiment) with the X-axis direction (first direction). That is, the spacer 600 is disposed at a position that does not overlap with the first adhesive body 710 when viewed from the X-axis direction. In the present embodiment, as shown in FIG. 5 , the spacer 600 is disposed at the end (the outer periphery of the long side surface portion 311) of the long side surface portion 311 of the first energy storage element 301 (and the second energy storage element 302). Specifically, the spacer 600 is disposed at four corners (ends on both sides in the Y-axis direction and both sides in the Z-axis direction) of the long side surface portion 311 of the first energy storage element 301 (and the second energy storage element 302). In this way, the spacer 600 is disposed at a position where the thickness of the first energy storage element 301 (and the second energy storage element 302) is thicker than the center of the long side surface portion 311.

[0055] In the present embodiment, spacer 600 is a double-sided tape and has electrical insulation properties. That is, spacer 600 has adhesive layers made of a pressure-sensitive adhesive on both sides in the X-axis direction (first direction) that are bonded to first energy storage element 301 and second energy storage element 302. Spacer 600 is, for example, a double-sided tape in which adhesive layers are provided on both sides of an electrically insulating base material such as a rectangular plate-shaped resin having a thickness of about 1 mm.

[0056] The first adhesive 710 is a member that is disposed in the recess 311a between the first energy storage element 301 and the second energy storage element 302 and that bonds the first energy storage element 301 and the second energy storage element 302. That is, the first adhesive 710 is disposed in the recess 311a formed in the center of the long side surface 311 of the first energy storage element 301 and in the recess 311a formed in the center of the long side surface 311 of the second energy storage element 302. In the present embodiment, the first adhesive 710 is an adhesive and has electrical insulation properties. The adhesive may be a liquid adhesive that is liquid before being injected (filled) into the recess 311a and solidifies to provide adhesion, a gel adhesive before being injected (filled), or a solid adhesive such as a hot melt adhesive.

[0057] The first adhesive body 710 is disposed over the entire surface of the portion of the long side surface portion 311 where the spacers 600 are not disposed. For example, the first energy storage element 301 and the second energy storage element 302 are temporarily fixed with the spacers 600, and then the first adhesive body 710 is poured into the gap between the spacers 600 between the first energy storage element 301 and the second energy storage element 302. As a result, the first adhesive body 710 is injected (filled) into the entire portion where the spacers 600 are not disposed between the first energy storage element 301 and the second energy storage element 302. The first adhesive body 710 is also disposed in portions of the long side surface portion 311 other than both ends of the bonding portion 310a in the Y-axis direction (portions where the spacers 600 are not disposed).

[0058] In order to fix the energy storage unit 12 having the energy storage element 300 to the exterior body 11 (exterior body main body 100), the energy storage device 10 includes, in addition to the above configuration, a second adhesive body 720 and a fixing member 800 (810, 820 and 830), as shown in Figures 6 and 7.

[0059] The second adhesive body 720 is a member that is disposed between the end member 400 and the energy storage element 300 and bonds the end member 400 and the energy storage element 300 together. For example, the end member 400 in the negative X-axis direction is disposed in a position in the X-axis direction (first direction) such that the first energy storage element 301 is sandwiched between the end member 400 and the second energy storage element 302. The second adhesive body 720 that bonds the end member 400 and the first energy storage element 301 together is disposed between the end member 400 and the first energy storage element 301. The same applies to the end member 400 in the positive X-axis direction. In this embodiment, the second adhesive body 720 is an adhesive and has electrical insulation properties. Any adhesive that can be used for the first adhesive body 710 can be used as the adhesive.

[0060] In the present embodiment, the second adhesive body 720 is injected (filled) and disposed over the entire area (the entire surface of the long side surface portion 311) between the end member 400 and the energy storage element 300. That is, the second adhesive body 720 is disposed over the entire joint portion 310a of the long side surface portion 311. A member similar to the spacer 600 (such as double-sided tape) may be disposed between the end member 400 and the energy storage element 300.

[0061] The fixing member 800 is a member that is disposed between the power storage unit 12 and the exterior body 11 and fixes the power storage unit 12 and the exterior body 11 together. Fixing members 810, 820, and 830 are disposed around the periphery (bottom and side surfaces) of the power storage unit 12 as the fixing member 800, and the fixing members 810, 820, and 830 fix the power storage unit 12 and the exterior body main body 100 of the exterior body 11 together. In the present embodiment, the fixing members 800 (810, 820, and 830) are adhesives and have electrical insulation properties. As the adhesive, any adhesive that can be used for the first adhesive body 710 can be used.

[0062] The fixing member 810 is a member that is disposed between the bottom surface 313 of the container 310 of the energy storage element 300 included in the energy storage unit 12 and the bottom wall portion 130 of the exterior body main body 100 included in the exterior body 11, and that fixes the bottom surface 313 and the bottom wall portion 130 together. In the present embodiment, the fixing member 810 is disposed by coating or the like, extending from one end member 400 to the other end member 400, on the bottom surface 313 of the plurality of energy storage elements 300 and between the pair of end members 400 and the bottom wall portion 130. The fixing member 810 bonds and fixes the bottom surface 313 of the plurality of energy storage elements 300 and the pair of end members 400 to the bottom wall portion 130.

[0063] In this way, the fixing member 810 is disposed between the bottom surface of the power storage unit 12 in the negative Z-axis direction and the bottom wall 130, and bonds and fixes the entire bottom surface to the bottom wall 130. The fixing member 810 may be disposed only on a part of the bottom surface of the power storage unit 12 in the negative Z-axis direction, and bonds and fixes the part of the bottom surface to the bottom wall 130.

[0064] The fixing member 820 is a member that is disposed between the end member 400 of the electricity storage unit 12 and the short side wall portion 110 of the exterior body main body 100 of the exterior body 11, and fixes the end member 400 to the short side wall portion 110. In the present embodiment, the fixing member 820 is disposed by being injected (filled) between the end member 400 and the short side wall portion 110 over the entire surface of the surface of the end member 400 that faces the short side wall portion 110, and bonds and fixes the entire surface of the end member 400 to the short side wall portion 110. In the present embodiment, a pair of fixing members 820 is disposed between the pair of end members 400 and the pair of short side wall portions 110, and fixes the pair of end members 400 to the pair of short side wall portions 110.

[0065] In this way, the fixing member 820 is disposed over the entire surface of both side surfaces in the X-axis direction of the electricity storage unit 12 between the both side surfaces and the pair of short side wall portions 110, and adheres and fixes the entire surface of both side surfaces to the pair of short side wall portions 110. The fixing member 820 may be disposed only on a part of the side surfaces of the electricity storage unit 12, and may adhere and fix the part of the side surfaces to the short side wall portions 110.

[0066] The fixing member 830 is a member that is arranged between the short side surface portion 312 of the container 310 of the energy storage element 300 included in the energy storage unit 12 and the long side wall portion 120 of the exterior body main body 100 included in the exterior body 11, and fixes the short side surface portion 312 and the long side wall portion 120. In the present embodiment, the fixing member 830 is arranged by being injected (filled) from one end member 400 to the other end member 400 of the pair of end members 400, into the short side surface portions 312 of the plurality of energy storage elements 300 and between the pair of end members 400 and the long side wall portion 120. The fixing member 830 bonds and fixes the short side surface portions 312 of the plurality of energy storage elements 300 and the pair of end members 400 to the long side wall portion 120. In this embodiment, a pair of fixing members 830 are arranged between a pair of short side surface portions 312 etc. and a pair of long side wall portions 120 of the container 310 of the energy storage element 300, and the pair of short side surface portions 312 etc. and the pair of long side wall portions 120 are fixed.

[0067] In this way, the fixing member 830 is disposed over the entire surface of both side surfaces in the Y-axis direction of the electricity storage unit 12 between the both side surfaces and the pair of long side wall portions 120, and adheres and fixes the entire surface of the both side surfaces to the pair of long side wall portions 120. The fixing member 830 may be disposed only on a part of the side surfaces of the electricity storage unit 12, and may adhere and fix the part of the side surfaces to the long side wall portions 120.

[0068] [4. Explanation of effects] According to the energy storage device 10 of this embodiment, the energy storage unit 12 includes a first adhesive body 710 disposed between the first energy storage element 301 and the second energy storage element 302 in a recess 311a formed by recessing the long side surface portion 311 of the first energy storage element 301, and a spacer 600 disposed at a position different from the first adhesive body 710. By disposing the first adhesive body 710 in the recess 311a of the first energy storage element 301, the thickness of the first adhesive body 710 can be increased, and by disposing the spacer 600 at a position different from the first adhesive body 710, the thickness of the first adhesive body 710 can be further increased. In particular, by disposing the spacer 600 between the first energy storage element 301 and the second energy storage element 302, it is possible to prevent the first adhesive body 710 from being compressed and becoming thinner, and it is possible to maintain the thickness of the first adhesive body 710 in a thick state. Furthermore, by disposing first adhesive body 710 in recess 311a of first energy storage element 301, stress that would tend to separate first adhesive body 710 from adhesively bonding first energy storage element 301 and second energy storage element 302 when first energy storage element 301 attempts to swell is dispersed. This makes it possible to prevent first energy storage element 301 and second energy storage element 302 from being separated. This increases the adhesive strength between first energy storage element 301 and second energy storage element 302, thereby improving the vibration resistance or impact resistance of energy storage device 10.

[0069] Forming recess 311a in first energy storage element 301 improves the frictional force between the inner surface of container 310 of first energy storage element 301 and electrode assembly 350, thereby suppressing movement of electrode assembly 350 within container 310. This also makes it possible to improve the vibration resistance or impact resistance of energy storage device 10 (first energy storage element 301).

[0070] Both the first adhesive body 710 and the spacer 600 have electrical insulation properties, which can improve the electrical insulation between the first energy storage element 301 and the second energy storage element 302. In particular, because the first adhesive body 710 and the spacer 600 are arranged over the entire surface of the long side surface portion 311, the electrical insulation between the first energy storage element 301 and the second energy storage element 302 can be further improved.

[0071] The spacer 600 has adhesive layers on both sides thereof that are bonded to the first energy storage element 301 and the second energy storage element 302. By bonding the spacer 600 to the first energy storage element 301 and the second energy storage element 302 in this manner, the first energy storage element 301 and the second energy storage element 302 are fixed via the spacer 600. This allows the first energy storage element 301 and the second energy storage element 302 to be fixed more firmly by the adhesion using the first adhesive body 710 and the adhesion using the spacer 600, thereby improving the vibration resistance or impact resistance of the energy storage device 10.

[0072] The first energy storage element 301 and the second energy storage element 302 can be temporarily fixed by adhesion using the spacer 600. In particular, if the adhesive layer of the spacer 600 is made of a pressure-sensitive adhesive, when adhering the first energy storage element 301 and the second energy storage element 302 with the first adhesive body 710, there is no need to wait for the first adhesive body 710 to harden, and the first energy storage element 301 and the second energy storage element 302 can be easily adhered. This makes it possible to easily realize a configuration that can improve the vibration resistance or impact resistance of the energy storage device 10.

[0073] First adhesive body 710 is disposed in recess 311a formed in the center of the surface (long side surface portion 311) of first energy storage element 301 that faces second energy storage element 302. By disposing first adhesive body 710 in recess 311a in the center of first energy storage element 301, first energy storage element 301 and second energy storage element 302 can be adhered in a balanced manner, thereby improving the vibration resistance or impact resistance of energy storage device 10.

[0074] The first energy storage element 301 and the second energy storage element 302 are prone to swelling at their central portions. By forming the recess 311a in the central portion of the first energy storage element 301, even if the central portion swells, a decrease in the frictional force between the inner surface of the container 310 and the electrode assembly 350 at the central portion is suppressed. This suppresses movement of the electrode assembly 350 within the container 310 of the first energy storage element 301, thereby improving the vibration resistance or impact resistance of the energy storage device 10 (first energy storage element 301). Furthermore, by arranging the first adhesive body 710 in the recess 311a in the central portion of the first energy storage element 301, even if the central portions of the first energy storage element 301 and the second energy storage element 302 tend to swell, the first adhesive body 710 presses against the central portions, thereby suppressing the swelling of the central portions.

[0075] The energy storage unit 12 has an end member 400 and a second adhesive body 720 that bonds the end member 400 and the first energy storage element 301. By bonding the end member 400 and the first energy storage element 301 with the second adhesive body 720 in this manner, movement of the first energy storage element 301 relative to the end member 400 can be suppressed, thereby improving the vibration resistance or impact resistance of the energy storage device 10.

[0076] By bonding the end member 400 and the first energy storage element 301 with the second adhesive body 720, there is no need to provide a member (such as a side plate) for fixing the end member 400 to the first energy storage element 301, thereby reducing the number of parts. Furthermore, by bonding the end member 400 to the first energy storage element 301, the end member 400 can be reinforced and deformation of the end member 400 can be suppressed. As a result, the energy storage device 10 can be made smaller, lighter, and more cost-effective.

[0077] Since the first adhesive body 710 and the second adhesive body 720 are also positioned on the joint 310a in the long side portion 311, even if the container 310 tries to expand, the first adhesive body 710 and the second adhesive body 720 protect the joint 310a, thereby suppressing damage to the joint 310a.

[0078] Fixing members 800 (810, 820, and 830) that fix the energy storage unit 12 to the exterior body 11 are arranged between the energy storage unit 12 and the exterior body 11. Fixing the energy storage unit 12 to the exterior body 11 with the fixing members 800 can suppress movement of the energy storage unit 12 (first energy storage element 301, second energy storage element 302, etc.) within the exterior body 11, thereby improving the vibration resistance or impact resistance of the energy storage device 10. Fixing the energy storage unit 12 to the exterior body 11 can suppress damage such as deformation or breakage of the bus bar that connects the energy storage element 300 in the energy storage unit 12 to the external terminal 210 attached to the exterior body 11.

[0079] Because the fixing member 800 is an adhesive, there is no need to arrange fixing members (bolts, etc.), and the number of parts can be reduced. This makes it possible to reduce the size, weight, and cost of the energy storage device 10. Because the fixing member 800 has electrical insulation properties, it is possible to prevent the energy storage elements 300 of the energy storage unit 12 from becoming electrically conductive with each other via the fixing member 800, or the energy storage elements 300 from becoming electrically conductive with other conductive members.

[0080] The effects achieved by recess 311a of first energy storage element 301 can be similarly applied to recess 311a of second energy storage element 302. The same applies to other energy storage elements 300.

[0081] [5. Explanation of Variations] (Variation 1) A first modification of the above embodiment will be described. Fig. 8 is a front view showing a configuration in which a spacer 601 and a first adhesive body 711 are arranged on an energy storage device 300 according to the first modification of the present embodiment. Fig. 8 is a view corresponding to Fig. 5.

[0082] 8, in this modification, a spacer 601 and a first adhesive body 711 are arranged instead of the spacer 600 and the first adhesive body 710 in the above embodiment. The other configurations are the same as those in the above embodiment, and therefore detailed description thereof will be omitted.

[0083] The spacer 601 is arranged in a ring shape on the outer periphery of the long side surface portion 311 of the energy storage element 300 so as to surround the periphery of the first adhesive body 711. Like the spacer 600 in the above embodiment, the spacer 601 is a double-sided tape and has electrical insulation properties. The first adhesive body 711 is arranged inside the spacer 601, specifically, in the center of the long side surface portion 311 of the energy storage element 300. In other words, the first adhesive body 711 is arranged in a recess 311a formed in the center of the long side surface portion 311. Like the first adhesive body 710 in the above embodiment, the first adhesive body 711 is an adhesive and has electrical insulation properties. In this way, the spacer 601 and the first adhesive body 711 are arranged in positions where they do not overlap when viewed from the X-axis direction.

[0084] The energy storage device according to this modification can achieve the same effects as the above embodiment. In this modification, the spacer 601 does not have to be annular, but may be linear extending in the Y-axis direction or the Z-axis direction, or may have another shape. The first adhesive body 711 may also have any shape as long as it corresponds to the shape of the spacer 601. The shapes of the spacer and first adhesive body disposed between two adjacent energy storage elements 300 are not particularly limited, and any shape is applicable.

[0085] (Variations 2 and 3) Modifications 2 and 3 of the above embodiment will be described. Fig. 9 is a cross-sectional view showing the configuration of first adhesive body 712 according to modification 2 of the present embodiment, and Fig. 10 is a cross-sectional view showing the configuration of first adhesive body 713 according to modification 3 of the present embodiment. Specifically, Figs. 9 and 10 are views corresponding to the upper parts of first energy storage element 301 and second energy storage element 302 shown in Fig. 6.

[0086] As shown in Fig. 9, in Modification 2, a first adhesive body 712 is arranged instead of the first adhesive body 710 in the above embodiment. As shown in Fig. 10, in Modification 3, a first adhesive body 713 is arranged instead of the first adhesive body 710 in the above embodiment. In Modifications 2 or 3, the first adhesive body 712 or 713 is arranged instead of all of the first adhesive bodies 710 in the above embodiment, but it may also be arranged instead of some of the first adhesive bodies 710. The other configurations of Modifications 2 and 3 are the same as those in the above embodiment, so detailed description will be omitted.

[0087] 9, the first adhesive body 712 has a plate-shaped insulating material 712a on its inside. The insulating material 712a is a flat (sheet-shaped) insulating material that extends parallel to the YZ plane and is disposed in the center of the first adhesive body 712 in the X-axis direction, across the entire first adhesive body 712 in the Y-axis and Z-axis directions. Examples of the insulating material include a heat conduction prevention sheet, a glass fiber sheet, or a ceramic plate. The insulating material 712a only needs to be disposed inside the first adhesive body 712, and the position, size, and shape of the insulating material 712a within the first adhesive body 712 are not particularly limited.

[0088] 10, the first adhesive body 713 has granular insulating material 713a inside. The insulating material 713a is granular (particulate) insulating material scattered throughout the first adhesive body 713. Examples of the insulating material include any of the insulating materials usable for the insulating material 712a described above that have been made into granular (particulate) form. The insulating material 713a may be disposed inside the first adhesive body 713, and the position, size (particle diameter), and shape (sphere, ellipsoid, cube, rectangular parallelepiped, etc.) of the insulating material 713a within the first adhesive body 713 are not particularly limited.

[0089] The energy storage devices according to Modifications 2 and 3 can achieve the same effects as the above-described embodiment. In particular, in Modifications 2 and 3, first adhesive body 712 or 713 has heat insulating material 712a or 713a inside, which allows heat insulating material 712a or 713a to be fixed together with first energy storage element 301 and second energy storage element 302. This makes it possible to improve the vibration resistance or impact resistance of the energy storage device even when heat insulating material 712a or 713a is disposed between first energy storage element 301 and second energy storage element 302.

[0090] By arranging the heat insulating material 712a or 713a inside the first adhesive body 712 or 713, the heat insulating material 712a or 713a can be easily arranged between the first energy storage element 301 and the second energy storage element 302. This makes it possible to insulate the first energy storage element 301 and the second energy storage element 302 with a simple configuration. Furthermore, by using the heat insulating material 712a or 713a with high creep resistance, the creep resistance of the first adhesive body 712 or 713 can be improved.

[0091] (Other variations) Although the power storage device according to the present embodiment (including its modified examples) has been described above, the present invention is not limited to the above-described embodiment. The disclosed embodiment is illustrative in all respects and is not restrictive, and the scope of the present invention includes all modifications within the meaning and scope of the claims.

[0092] In the above embodiment, the energy storage element 300 has the recess 311a on both of the pair of long side surface portions 311 of the container 310, but the recess 311a may be provided on only one of the pair of long side surface portions 311. Any of the energy storage elements 300 included in the energy storage unit 12 may not have the recess 311a on both of the pair of long side surface portions 311.

[0093] In the above embodiment, a spacer 600 or 601 (hereinafter referred to as spacer 600, etc.) and a first adhesive body 710, 711, 712 or 713 (hereinafter referred to as first adhesive body 710, etc.) are arranged between every two adjacent energy storage elements 300. However, it is also possible that both or one of the spacer 600, etc. and the first adhesive body 710, etc. are not arranged between any two energy storage elements 300.

[0094] In the above embodiment, the spacers 600, etc. and the first adhesive body 710, etc. are arranged over the entire surface of the long side surface portion 311. However, the spacers 600, etc. and the first adhesive body 710, etc. may not be arranged over a portion of the long side surface portion 311. Even in this case, the electrical insulation of the energy storage element 300 can be ensured by, for example, arranging an insulating film (such as a shrink tube) around the container 310 to cover the outer surface of the container 310.

[0095] In the above embodiment, the energy storage element 300 has the recess 311a in the center of the long side surface 311 of the container 310. However, the recess 311a may be formed at the end of the long side surface 311 instead of at the center of the long side surface 311. In other words, the first adhesive body 710 and the like may be arranged in the recess 311a at the end of the long side surface 311, and the spacer 600 and the like may be arranged in the center of the long side surface 311.

[0096] In the above embodiment, the spacer 600 and the like are electrically insulating double-sided tape having adhesive layers made of pressure-sensitive adhesive on both sides. However, the spacer 600 and the like may also have a hook-and-loop fastener structure that is detachably attached, such as Magic Tape (registered trademark) or Velcro (registered trademark) tape. Furthermore, the spacer 600 and the like may have an adhesive layer on only one side, or may have adhesive layers on both sides. The adhesive layer of the spacer 600 and the like may be made of an adhesive other than a pressure-sensitive adhesive. Furthermore, the spacer 600 and the like may be a conductive material that does not have electrical insulation properties.

[0097] In the above embodiment, the first adhesive body 710 and the like are electrically insulating adhesives. However, the first adhesive body 710 and the like may be conductive adhesives that do not have electrical insulating properties, or may be materials that are not so-called adhesives as long as they have an adhesive function, and the materials are not particularly limited. The same applies to the second adhesive body 720 and the fixing member 800 (810, 820, and 830). The fixing members 820 and 830 may be materials such as fillers that do not have an adhesive function.

[0098] In the above embodiment, a pair of second adhesive bodies 720 are arranged relative to a pair of end members 400, but one or both of the pair of second adhesive bodies 720 may not be arranged. For example, a configuration in which one or both of the pair of end members 400 are not arranged may be used, in which case the second adhesive body 720 may not be arranged on the side where the end member 400 is not arranged, and the fixing member 820 may fix (adhere) the exterior body 11 and the energy storage element 300.

[0099] In the above embodiment, the fixing member 810, the pair of fixing members 820, and the pair of fixing members 830 are arranged between the energy storage unit 12 and the exterior body 11 to fix the energy storage unit 12 and the exterior body 11. However, the energy storage unit 12 and the exterior body 11 may be fixed without any fixing member 800 among the fixing member 810, the pair of fixing members 820, and the pair of fixing members 830 being arranged between the energy storage unit 12 and the exterior body 11. In other words, at least one fixing member 800 among the fixing member 810, the pair of fixing members 820, and the pair of fixing members 830 may be arranged between the energy storage unit 12 and the exterior body 11. In other words, the fixing member 800 may fix the bottom surface portions 313 and short side surface portions 312 of the plurality of energy storage elements 300 (such as the first energy storage element 301 and the second energy storage element 302) and at least one of the pair of end members 400 to the exterior body 11. Alternatively, a configuration may be adopted in which no fixing member 800 is disposed between the power storage unit 12 and the exterior body 11, and the power storage unit 12 and the exterior body 11 are not fixed to each other.

[0100] Any combination of the components of the above-described embodiment and its modifications is also included within the scope of the present invention. [Industrial Applicability]

[0101] The present invention can be applied to an electricity storage device or the like that includes an electricity storage element such as a lithium ion secondary battery. [Explanation of symbols]

[0102] 10. Energy storage device 11 Exterior body 12 Energy storage unit 100 exterior body 110 Short side wall 120 Long side wall 130 Bottom wall 200 Exterior body lid 210 External terminal 300 Energy storage element 301 First storage element 302 Second storage element 310 Container 310a joint 311 Long side part 311a Recess 312 Short side part 313 Bottom part 320 Container body 330 Container lid 340 Electrode terminal 350 Electrode body 351 End 360 Current Collector 400 End member 500 busbar 600, 601 spacer 710, 711, 712, 713 First adhesive body 712a, 713a Insulation 720 Second adhesive body 800, 810, 820, 830 Fixing members

Claims

1. A power storage device including a power storage unit having a first power storage element and a second power storage element arranged in a first direction, the first storage element has a recessed surface facing the second storage element, The power storage unit further comprises: a first adhesive body disposed in the recess and adhering the first energy storage element and the second energy storage element; a spacer disposed between the first storage element and the second storage element, the spacer being disposed at a position different from the first adhesive body in a second direction intersecting the first direction; The recess is formed by recessing a central portion of the surface of the first storage element in the second direction. Energy storage device.

2. The spacer has an adhesive layer on both sides in the first direction, the adhesive layer being attached to the first storage element or the second storage element. The power storage device according to claim 1 .

3. The power storage unit further comprises: an end member disposed at a position where the first storage element is sandwiched between the end member and the second storage element in the first direction; a second adhesive body disposed between the end member and the first energy storage element and adhering the end member and the first energy storage element together; The electricity storage device according to claim 1 or 2.

4. moreover, an exterior body that houses the power storage unit; a fixing member that fixes the power storage unit and the exterior body, The electricity storage device according to any one of claims 1 to 3.

5. The first adhesive body has a heat insulating material therein. The electricity storage device according to any one of claims 1 to 4.

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