Power storage device

Abstract

This power storage device comprises a power storage element, a spacer, and an exterior body. The spacer includes: a spacer body opposing the power storage element in a first direction, which is the direction of alignment of the power storage element and the spacer; and a spacer projection part projecting from the spacer body on one side in a second direction, which is a direction intersecting the first direction. The exterior body includes a bottom part on one side, in the second direction, of the power storage element and the spacer. The bottom part includes a bottom wall that forms a space between the power storage element and the spacer. The spacer projection part includes a first wall section that is disposed in the space and that extends to one side in the first direction, which is the direction facing the power storage element.

Description

Power storage device

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

[0002] Patent document 1 discloses an energy storage device module that includes a cell holder that holds batteries, the cell holder having a plurality of first ribs on the back wall that define a first air flow path, and a plurality of protruding portions on the bottom wall that define a second air flow path.

[0003] JP 2016-207534 A

[0004] In the conventional energy storage device module disclosed in Patent Document 1, air flow paths (first air flow path and second air flow path) are formed in the cell holder to improve the heat dissipation (cooling performance) of the battery. However, if air does not flow easily through these air flow paths, there is a risk that the cooling performance of the battery will not be improved.

[0005] The present invention was made by the inventors of the present application by focusing on the above-mentioned problem, and has an object to provide an electricity storage device that can improve the cooling performance of electricity storage elements.

[0006] An energy storage device according to one embodiment of the present invention comprises an energy storage element, a spacer, and an outer casing, wherein the spacer comprises a spacer main body facing the energy storage element in a first direction in which the energy storage element and the spacer are aligned, and a spacer protrusion protruding from the spacer main body to one side in a second direction that intersects the first direction, wherein the outer casing comprises a bottom portion on the one side of the second direction relative to the energy storage element and the spacer, the bottom portion comprising a bottom wall that forms a space between the energy storage element and the spacer, and the spacer protrusion portion is arranged in the space and comprises a first wall portion extending to one side of the first direction that is the direction toward the energy storage element.

[0007] According to the electricity storage device of the present invention, the cooling performance of the electricity storage elements can be improved.

[0008] FIG. 1 is a perspective view showing a configuration of an energy storage device according to an embodiment. FIG. 2 is an exploded perspective view showing energy storage elements and a spacer of an energy storage unit included in the energy storage device according to an embodiment. FIG. 3 is a perspective view showing a configuration of an energy storage element according to an embodiment. FIG. 4 is a perspective view showing a configuration of a spacer according to an embodiment. FIG. 5 is a perspective view showing a configuration of a spacer according to an embodiment. FIG. 6 is a cross-sectional view showing a configuration of a spacer protrusion of a spacer according to an embodiment. FIG. 7 is a perspective view showing a configuration of an exterior body main body according to an embodiment. FIG. 8 is a cross-sectional view showing a positional relationship between an exterior body main body, an energy storage element, and a spacer according to an embodiment. FIG. 9 is a cross-sectional view showing a state in which a refrigerant flows within a space in an exterior body main body according to an embodiment. FIG. 10 is a cross-sectional view showing a configuration of a spacer protrusion of a spacer according to a first modification of the embodiment. FIG. 11 is a cross-sectional view showing a configuration of a spacer protrusion of a spacer according to a second modification of the embodiment.

[0009] (1) An energy storage device according to one aspect of the present invention comprises an energy storage element, a spacer, and an outer casing, wherein the spacer comprises a spacer main body facing the energy storage element in a first direction in which the energy storage element and the spacer are aligned, and a spacer protrusion protruding from the spacer main body to one side in a second direction that intersects the first direction, wherein the outer casing comprises a bottom on the one side of the second direction relative to the energy storage element and the spacer, the bottom comprising a bottom wall that forms a space between the energy storage element and the spacer, and the spacer protrusion is arranged in the space and comprises a first wall portion extending to one side of the first direction that is the direction toward the energy storage element.

[0010] In an energy storage device according to one aspect of the present invention, the spacer protrusion protruding to one side in the second direction is disposed in a space between the bottom wall of the bottom of the exterior body and the energy storage element and the spacer, and includes a first wall extending to one side in the first direction, which is the direction toward the energy storage element. By providing the first wall within the space, when a refrigerant such as air flows through the space, the refrigerant flowing toward the spacer protrusion is facilitated by the first wall toward the spacer body (energy storage element). This improves the cooling performance of the energy storage element according to the energy storage device.

[0011] (2) In the energy storage device described in (1) above, the spacer protrusion may further include a second wall portion extending from the first wall portion toward one side in the second direction or in a direction inclined from the one side in the second direction.

[0012] According to the energy storage device described in (2) above, the spacer protrusion of the spacer includes a second wall extending from the first wall toward one side in the second direction or in a direction inclined from that direction, whereby the second wall gradually narrows the flow path of the refrigerant flowing toward the first wall, making it easier for the refrigerant to flow toward the spacer body (energy storage element).

[0013] (3) In the storage device described in (1) or (2) above, the bottom may be arranged between the bottom wall and the first wall portion when viewed from the first direction, and may further include an extension portion extending to one side of the first direction.

[0014] According to the energy storage device described in (3) above, the bottom of the exterior body has an extension extending to one side in the first direction between the bottom wall and the first wall. The extension on the bottom may make it difficult for a refrigerant, such as air, to flow toward the spacer body (energy storage element). In such cases, providing the first wall on the spacer protrusion is highly effective in facilitating the flow of the refrigerant toward the spacer body (energy storage element).

[0015] (4) In the energy storage device described above in (3), the extension portion may protrude further toward the one side in the first direction than the first wall portion.

[0016] According to the energy storage device described in (4) above, the extension of the bottom of the exterior body protrudes further in the first direction than the first wall, making it more difficult for the refrigerant to flow toward the spacer main body (energy storage element). Therefore, providing the first wall on the spacer protruding portion further enhances the effect of facilitating the refrigerant to flow toward the spacer main body (energy storage element).

[0017] (5) In the energy storage device described in any one of (1) to (4) above, the spacer may be an end spacer located furthest to the other side in the first direction among a plurality of spacers provided in the energy storage device.

[0018] According to the energy storage device described in (5) above, when the spacer is an end spacer, the refrigerant does not easily flow toward the spacer body (energy storage element). Therefore, providing the first wall portion on the spacer protrusion is highly effective in facilitating the refrigerant to flow toward the spacer body (energy storage element).

[0019] 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 modifications thereof). 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 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.

[0020] In the following description and drawings, the X-axis direction is defined as the short-side direction of the exterior body, the arrangement direction of a pair of terminals of the energy storage element, or the opposing direction of a pair of short side surfaces of the container for the energy storage element. The Y-axis direction is defined as the long-side direction of the exterior body, the arrangement direction of multiple energy storage elements or multiple spacers, the arrangement direction of the energy storage element and spacers, the thickness direction (flattening direction) of the energy storage element or spacer, or the opposing direction of a pair of long side surfaces of the container for the energy storage element. The Z-axis direction is defined as the protruding direction of the terminals of the energy storage element, the arrangement direction of the container body and the container lid of the energy storage element, the arrangement direction of the exterior body body and the lid of the exterior body, the opposing direction of the opening and bottom wall of the exterior body, 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.

[0021] 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. When simply referring to the X-axis direction, this refers to both or either of the positive X-axis direction and the negative X-axis direction. When referring to one side and the other side of the X-axis direction, this refers to one or the other of the positive X-axis direction and the negative X-axis direction. The same applies to the Y-axis and Z-axis directions. Hereinafter, the Y-axis direction will also be referred to as the first direction, the positive Y-axis direction will also be referred to as one side of the first direction, and the negative Y-axis direction will also be referred to as the other side of the first direction. The Z-axis direction will also be referred to as the second direction, the negative Z-axis direction will also be referred to as one side of the second direction, and the positive Z-axis direction will also be referred to as the other side of the second direction. The X-axis direction will also be referred to as the third direction. Expressions indicating relative directions or orientations, such as "parallel" and "orthogonal," may also include cases where the directions or orientations are not strictly those. Two directions being parallel (or perpendicular) does not only mean that the two directions are completely parallel (or perpendicular), but also that the two directions are substantially parallel (or perpendicular), i.e., that there is a difference of, for example, about a few percent. In the following description, the term "insulating" means "electrically insulating." An insulating material has a volume resistivity of 1×10 １０ It is preferable that the material be made of a material with a resistance of Ωm or more.

[0022] (Embodiment) [1 Description of Energy Storage Device 1] First, a schematic configuration of an energy storage device 1 according to this embodiment will be described. FIG. 1 is a perspective view showing the configuration of the energy storage device 1 according to this embodiment. FIG. 1 shows the energy storage device 1 in a state where a lid 320 is removed from an exterior body main body 310 of an exterior body 300. As a result, FIG. 1 illustrates the energy storage unit 10 disposed inside the exterior body 300. FIG. 2 is an exploded perspective view showing the energy storage elements 100 and spacers 200 of the energy storage unit 10 provided in the energy storage device 1 according to this embodiment. FIG. 2 disassembles the components provided in the energy storage unit 10 and illustrates two energy storage elements 100 and three spacers 200 (two spacers 200a and one spacer 200b) located at the end of the energy storage unit 10 in the negative Y-axis direction.

[0023] The power storage device 1 is a device that can charge electricity from an external source and discharge electricity to an external source. The power storage device 1 is used for power storage purposes, power supply purposes, etc. The power storage device 1 is used as a battery for driving or starting the engine of a mobile object such as an automobile, a motorcycle, a personal watercraft, a ship, a snowmobile, an agricultural machine, a construction machine, an automatic guided vehicle (AGV), 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 fossil fuel (gasoline, diesel, liquefied natural gas, etc.) 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 1 can also be used as a stationary battery for home or business use.

[0024] 1 , the energy storage device 1 includes an energy storage unit 10 and an exterior body 300 that houses the energy storage unit 10. The energy storage device 1 also includes external terminals (a positive electrode external terminal and a negative electrode external terminal) for electrically connecting to an external device, but these are not shown or described here. In addition to the above components, the energy storage device 1 may also include electrical devices such as a circuit board and a relay that monitor or control the charge state and discharge state of the energy storage unit 10.

[0025] The energy storage unit 10 is a battery module (battery assembly) including a plurality of energy storage elements 100. The energy storage unit 10 has a generally rectangular parallelepiped shape that is elongated in the Y-axis direction (first direction) by arranging the plurality of energy storage elements 100 and spacers 200 alternately in the Y-axis direction (first direction). The energy storage unit 10 includes a plurality of energy storage elements 100 and a plurality of spacers 200 (200a, 200b). The energy storage unit 10 also includes bus bars that connect the energy storage elements 100 in series or in parallel, a bus bar frame that holds the bus bars, and bus bars that connect the energy storage elements 100 to external terminals, but these are not shown in the drawings. The bus bars may connect all of the energy storage elements 100 in series, or may connect some of the energy storage elements 100 in parallel and then connect them in series, or may connect all of the energy storage elements 100 in parallel. The energy storage unit 10 is a non-constrained type module that does not include any restraining members (end plates, side plates, etc.) that restrain the plurality of energy storage elements 100 and spacers 200 in the Y-axis direction.

[0026] The energy storage element 100 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 100 has a rectangular parallelepiped shape (square or rectangular) that is flattened in the Y-axis direction. In this embodiment, a plurality of energy storage elements 100 are arranged side by side in the Y-axis direction. However, the number of arranged energy storage elements 100 is not particularly limited and may be one, several tens of energy storage elements 100, or more. The size and shape of the energy storage element 100 are also not particularly limited and may be an elongated cylinder, an elliptical cylinder, a cylindrical shape, a polygonal prism shape other than a rectangular parallelepiped, or the like. The energy storage element 100 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, or may be a capacitor. The energy storage element 100 may be a primary battery instead of a secondary battery. The energy storage element 100 may be a battery using a solid electrolyte. The energy storage element 100 may be a pouch-type energy storage element.

[0027] The spacer 200 is a flat member in the Y-axis direction that is arranged alongside the energy storage element 100 in the Y-axis direction and provides insulation and / or thermal insulation between the energy storage element 100 and other components. The spacer 200 is an insulating or thermal insulating plate that is arranged in the positive or negative Y-axis direction of the energy storage element 100 and provides insulation and / or thermal insulation between the energy storage elements 100 and each other or between the energy storage element 100 and the exterior body 300. The spacer 200 has wall portions on both sides of the energy storage element 100 in the X-axis direction and on both sides of the energy storage element 100 in the Z-axis direction, thereby functioning as a holder that holds the energy storage element 100 and positions the energy storage element 100. The spacer 200 has flow paths formed therein through which a refrigerant (a fluid such as air) flows, and also functions to cool the energy storage element 100.

[0028] The spacer 200 is formed from an insulating material 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), polyethersulfone (PES), polyamide (PA), ABS resin, or a composite material thereof, or a material having heat insulating properties such as mica.

[0029] Hereinafter, the spacers 200 arranged between the two energy storage elements 100 (spacers 200 other than those at both ends of the energy storage unit 10 in the Y-axis direction) will also be referred to as spacers 200a. The spacers 200 arranged at both ends of the energy storage unit 10 in the Y-axis direction (between the energy storage elements 100 at the ends and the exterior body 300) will also be referred to as spacers 200b. The spacers 200 (spacers 200a, 200b) are arranged alternately with the energy storage elements 100. While FIG. 2 shows a configuration in which two energy storage elements 100, two spacers 200a, and one spacer 200b are arranged alternately, the other spacers 200a and 200b are also arranged alternately with the energy storage elements 100.

[0030] Specifically, as shown in FIG. 2 , the spacer 200a is an intermediate spacer (intermediate holder, middle holder) that has wall portions on both sides in the X-axis direction and on both sides in the Z-axis direction of two energy storage elements 100 arranged on both sides of the spacer 200a in the Y-axis direction and that holds the two energy storage elements 100. The spacer 200b is an end spacer (end holder) that has wall portions on both sides in the X-axis direction and on both sides in the Z-axis direction of one energy storage element 100 arranged on one side of the spacer 200b in the Y-axis direction and that holds the one energy storage element 100. In other words, the energy storage element 100 located at the end of the energy storage unit 10 in the Y-axis direction is held by the spacer 200a and the spacer 200b. The other energy storage elements 100 are held by the two spacers 200a. In this way, the spacer 200a has a double-sided support configuration that supports two energy storage elements 100 on both sides in the Y-axis direction, while the spacer 200b has a single-sided support configuration that supports one energy storage element 100 on only one side in the Y-axis direction. The spacer 200a may hold one energy storage element 100 on each half of the spacer 200a in the Y-axis direction, or may hold one energy storage element 100 on only one side of the spacer 200a in the Y-axis direction. All the spacers 200 (spacers 200a, 200b) may be made of the same material, or any of the spacers 200 may be made of a different material.

[0031] The exterior body 300 is a container (case) having a substantially rectangular parallelepiped (box-shaped) shape that constitutes the exterior body (housing, outer shell) of the energy storage device 1. The exterior body 300 is disposed outside the energy storage unit 10, fixes the energy storage unit 10 in a predetermined position, and protects it from impacts and the like. The exterior body 300 is a metal case formed from a metal member such as aluminum, aluminum alloy, stainless steel, iron, or plated steel sheet. In this embodiment, the exterior body 300 is formed by aluminum die-casting (aluminum die-casting). The exterior body 300 may be formed from an insulating member such as any resin material that can be used for the spacer 200 included in the energy storage unit 10.

[0032] As shown in FIG. 1 , the exterior body 300 includes an exterior body main body 310 that constitutes the main body of the exterior body 300, and a lid body 320 that constitutes the lid body of the exterior body 300. The exterior body main body 310 is a housing (chassis) with a first opening 310a formed in the positive direction of the Z axis, and accommodates the energy storage unit 10 (the energy storage element 100 and the spacer 200 (spacers 200a and 200b)). The lid body 320 is a flat, rectangular member that closes the first opening 310a of the exterior body main body 310. The rectangular first opening 310a is formed in the exterior body main body 310, and after the energy storage unit 10 is inserted through the first opening 310a, the exterior body main body 310 and the lid body 320 are joined by screwing with bolts or the like, welding, adhesive, or the like. This results in the exterior body 300 having a structure in which the interior is sealed (sealed). A terminal block for external terminals (positive external terminal and negative external terminal) may be attached to the exterior body 310 or the lid 320, and the external terminals may be arranged on the terminal block.

[0033] Next, the configurations of the energy storage device 100, the spacer 200 (particularly, the spacer 200b), and the exterior body 300 (particularly, the exterior body main body 310) will be described in detail.

[0034] [1.1 Description of Energy Storage Element 100] Fig. 3 is a perspective view showing the configuration of the energy storage element 100 according to this embodiment. Fig. 3 shows an enlarged view of the energy storage element 100 shown in Fig. 2. Since the multiple energy storage elements 100 included in the energy storage unit 10 all have the same configuration, Fig. 3 shows one energy storage element 100, and the configuration of one energy storage element 100 will be described in detail below.

[0035] As shown in FIG. 3 , the energy storage element 100 includes a container 110 and a pair of terminals 140 (positive and negative electrodes). The container 110 contains an electrode assembly, a pair of current collectors (positive and negative electrodes), and an electrolyte (non-aqueous electrolyte). Gaskets are disposed between the terminals 140 and current collectors and the container 110, but these are not shown. The electrolyte may be of any type, as long as it does not impair the performance of the energy storage element 100, and various types can be selected. The gasket may be made of any insulating material. In addition to the above components, the energy storage element 100 may also include spacers disposed on the sides of the electrode assembly, an insulating film encasing the electrode assembly, and an insulating film (such as a shrink tube) covering the outer surface of the container 110.

[0036] The container 110 is a rectangular parallelepiped (square or box-shaped) case including a container body 120 with an opening formed therein and a container lid 130 that closes the opening of the container body 120. The container body 120 is a rectangular cylindrical member with a bottom that constitutes the main body of the container 110, and has an opening formed on the positive side of the Z axis. The container lid 130 is a rectangular plate-like member that is elongated in the X axis direction and constitutes the lid of the container 110, and is disposed in the positive direction of the Z axis of the container body 120. The container lid 130 is provided with a gas exhaust valve 131 that releases pressure inside the container 110 if the pressure inside the container 110 increases excessively, a liquid injection portion (not shown) for injecting electrolyte into the container 110, and other components. The material of the container 110 (the container body 120 and the container lid 130) is not particularly limited and can be a weldable (joinable) metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel sheet, but resin can also be used.

[0037] After the electrode assembly and the like are housed inside the container body 120, the container body 120 and the container lid 130 are joined by welding or the like, thereby sealing the interior of the container 110. The container 110 has a pair of long sides 111 on both sides in the Y-axis direction, a pair of short sides 112 on both sides in the X-axis direction, and a bottom surface 113 on the negative Z-axis side. The long sides 111 are rectangular flat portions that form the long sides of the container 110 and are arranged opposite adjacent spacers 200 in the Y-axis direction. The long sides 111 are adjacent to the short sides 112 and the bottom surface 113 and have a larger area than the short sides 112. The short sides 112 are rectangular flat portions that form the short sides of the container 110 and are arranged opposite the walls of the spacers 200 and the exterior body 300 in the X-axis direction. The short sides 112 are adjacent to the long sides 111 and the bottom surface 113 and have a smaller area than the long sides 111. The bottom surface 113 is a rectangular flat surface that forms the bottom surface of the container 110, and is arranged opposite the wall portion of the spacer 200 and the bottom wall of the exterior body 300 in the Z-axis direction. The bottom surface 113 is arranged adjacent to the long side surface 111 and the short side surface 112.

[0038] The terminals 140 are electrode terminals (positive and negative terminals) of the energy storage element 100 that are disposed on the container lid 130. Specifically, the terminals 140 are disposed in a state where they protrude from the upper surface (terminal arrangement surface) of the container lid 130 in the positive direction of the Z axis. The terminals 140 are electrically connected to the positive and negative electrode plates of the electrode assembly via current collectors. In other words, the terminals 140 are metal members that conduct electricity stored in the electrode assembly to the external space of the energy storage element 100 and introduce electricity into the internal space of the energy storage element 100 to store electricity in the electrode assembly. The terminals 140 are formed of aluminum, an aluminum alloy, copper, a copper alloy, or the like.

[0039] The electrode assembly is an electricity storage element (power generating element) formed by stacking a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate is a positive electrode current collector foil, which is a metal foil made of a metal such as aluminum or an aluminum alloy, on which a positive electrode active material layer is formed. The negative electrode plate is a negative electrode current collector foil, which is a metal foil made of a metal such as copper or a copper alloy, on which a negative electrode active material layer is formed. Any known material capable of absorbing and releasing charge-transporting ions can be used as the active material for the positive electrode active material layer and the negative electrode active material layer. The separator can be a microporous resin sheet or nonwoven fabric. In this embodiment, the electrode assembly is formed by stacking electrode plates (positive electrode plates and negative electrode plates) in the Y-axis direction. The electrode assembly may be of any shape, such as a wound electrode assembly formed by winding electrode plates (positive electrode plates and negative electrode plates), a stacked electrode assembly formed by stacking multiple flat electrode plates, or a bellows-shaped electrode assembly formed by folding electrode plates in an accordion-like shape.

[0040] The current collectors are conductive current collecting members (positive and negative current collectors) electrically and mechanically connected to the terminal 140 and the electrode body. The positive current collector is made of aluminum, an aluminum alloy, or the like, similar to the positive current collector foil of the positive electrode plate of the electrode body, and the negative current collector is made of copper, a copper alloy, or the like, similar to the negative current collector foil of the negative electrode plate of the electrode body.

[0041] [1.2 Description of Spacer 200b] Next, the configuration of spacer 200b of spacer 200 will be described in detail. FIGS. 4 and 5 are perspective views showing the configuration of spacer 200 (spacer 200b) according to this embodiment. FIG. 4 is an enlarged view of spacer 200b shown in FIG. 2, viewed obliquely from below. FIG. 5 shows the configuration of spacer 200b shown in FIG. 2 rotated 90° about a line passing through the center of spacer 200b and parallel to the Z axis. FIG. 6 is a cross-sectional view showing the configuration of spacer protrusion 220 of spacer 200 (spacer 200b) according to this embodiment. FIG. 6 shows a cross-section of the end of spacer 200b shown in FIG. 5 in the negative Z-axis direction, taken along a plane passing through line VI-VI and parallel to the YZ plane.

[0042] The spacer 200b is the spacer 200 located at the end of the energy storage unit 10 in the negative Y-axis direction. In other words, the spacer 200b is the end spacer located furthest in the negative Y-axis direction (the other side in the first direction) among the multiple spacers 200 included in the energy storage device 1. The spacer 200b faces a first exterior body wall portion 312 (described later) included in the exterior body main body 310 of the exterior body 300, and is positioned adjacent to the first exterior body wall portion 312 (see FIG. 8 , etc.). As shown in FIGS. 4 and 5 , the positive and negative X-axis halves of the spacer 200b have the same shape. In other words, the spacer 200b has a shape that is symmetrical with respect to a plane that passes through the center position and is parallel to the YZ plane. The spacer 200b includes a spacer main body 210, a spacer protrusion 220, a spacer wall portion 230, and a pair of legs 240.

[0043] The spacer body 210 is a flat, rectangular portion that constitutes the main body of the spacer 200b and is disposed parallel to the XZ plane. The spacer body 210 faces the energy storage device 100 in the Y-axis direction (first direction), which is the alignment direction of the energy storage device 100 and the spacer 200b. Specifically, the spacer body 210 is disposed in the negative Y-axis direction of the energy storage device 100 located at the end of the energy storage unit 10 in the negative Y-axis direction. The spacer body 210 is disposed opposite the long side surface 111 of the container 110 of the energy storage device 100 that faces the spacer body 210 in the Y-axis direction, so as to cover the entire surface of the long side surface 111 that faces the spacer body 210, and is disposed in contact with the long side surface 111.

[0044] As shown in FIG. 5 , a plurality of protrusions 211 are provided on the surface of the spacer main body 210 in the positive direction of the Y axis. The plurality of protrusions 211 are a plurality of ribs (L-shaped curved ribs) that extend in the positive direction of the Z axis from the negative end of the spacer main body 210, curve toward both sides in the X axis direction (the positive or negative X axis direction), and extend to both sides in the X axis direction (the positive or negative X axis direction). The plurality of protrusions 211 form a plurality of L-shaped curved spaces 212. The plurality of spaces 212 extend in the positive direction of the Z axis from the negative end of the spacer main body 210, curve toward both sides in the X axis direction, and extend to both sides in the X axis direction. The plurality of spaces 212 are spaces that are disposed between the spacer main body 210 and the energy storage device 100 when the spacer 200b and the energy storage device 100 are assembled. The spaces 212 are flow paths for a coolant that flows between the spacer main body 210 and the energy storage device 100. The refrigerant flowing through the space 212 is a fluid, such as a gas such as air or a liquid, for cooling the energy storage element 100. The space 212 can also be used as a space into which a jig is inserted when holding the energy storage element 100 during manufacturing (assembly).

[0045] The spacer walls 230 are walls arranged at both ends in the Z-axis direction and both ends in the X-axis direction of the spacer body 210. The spacer walls 230 are arranged on both sides in the Z-axis direction and both ends in the X-axis direction of the energy storage element 100, and cover the four corners of the energy storage element 100 located at both ends in the Z-axis direction and both ends in the X-axis direction of the energy storage element 100. This allows the spacer 200b to hold the energy storage element 100. Specifically, the spacer walls 230 include a pair of first spacer walls 231, a pair of second spacer walls 232, a pair of third spacer walls 233, and a pair of fourth spacer walls 234.

[0046] The pair of first spacer wall portions 231 are flat plate-shaped portions that protrude in the positive Y-axis direction from both X-axis direction ends of the spacer main body 210 at the positive Z-axis direction, and are arranged parallel to the XY plane. The pair of first spacer wall portions 231 are arranged opposite the container lid portion 130 of the container 110 of the energy storage device 100 in the Z-axis direction, at both X-axis direction ends of the energy storage device 100 in the positive Z-axis direction. The pair of second spacer wall portions 232 are flat plate-shaped portions that protrude in the positive Y-axis direction from both X-axis direction ends of the spacer main body 210 at the negative Z-axis direction, and extend in the X-axis direction, and are arranged parallel to the XY plane. The pair of second spacer wall portions 232 are arranged opposite the bottom surface 113 of the container 110 of the energy storage device 100 in the Z-axis direction, at both X-axis direction ends of the energy storage device 100 in the negative Z-axis direction.

[0047] The pair of third spacer wall portions 233 are flat plate-shaped portions that protrude in the positive Y-axis direction from the positive Z-axis end portions of both X-axis direction ends of the spacer main body 210 and are arranged parallel to the YZ plane. The pair of third spacer wall portions 233 are arranged opposite the short side surfaces 112 of the container 110 of the energy storage device 100 in the X-axis direction, on both sides of the positive Z-axis end portion of the energy storage device 100 in the X-axis direction. The pair of fourth spacer wall portions 234 are flat plate-shaped portions that protrude in the positive Y-axis direction from the negative Z-axis end portions of both X-axis direction ends of the spacer main body 210 and are arranged parallel to the YZ plane. The pair of fourth spacer wall portions 234 are arranged opposite the short side surfaces 112 of the container 110 of the energy storage device 100 in the X-axis direction, on both sides of the negative Z-axis end portion of the energy storage device 100 in the X-axis direction.

[0048] The spacer protrusion 220 is a portion that protrudes from the spacer main body 210 in the negative Z-axis direction (one side in the second direction, which is a direction intersecting the first direction). In this embodiment, in the spacer 200b, the portion that is further in the positive Z-axis direction than the second spacer wall portion 232 in the Z-axis direction is the spacer main body 210, and the portion that is further in the negative Z-axis direction than the second spacer wall portion 232 is the spacer protrusion 220 (see FIG. 6). In other words, the spacer protrusion 220 is a portion that protrudes in the negative Z-axis direction beyond the spacer main body 210 and the second spacer wall portion 232. As shown in FIGS. 4 to 6, the spacer protrusion 220 includes a first wall portion 221, a second wall portion 222, and a pair of third wall portions 223.

[0049] The first wall portion 221 is disposed at the end of the spacer protrusion 220 in the negative Z-axis direction and extends in the positive Y-axis direction (one side in the first direction). In this embodiment, the first wall portion 221 is a plate-shaped portion facing the Z-axis direction. Specifically, the first wall portion 221 is a flat, rectangular portion that protrudes in the positive Y-axis direction from the center of the end of the spacer protrusion 220 in the negative Z-axis direction and is parallel to the XY plane extending in the X-axis direction. The first wall portion 221 is a long wall that is long in the X-axis direction.

[0050] The second wall portion 222 is a portion that extends from the first wall portion 221 in the negative Z-axis direction (one side in the second direction). In this embodiment, the second wall portion 222 is a plate-shaped portion that faces the Y-axis direction. Specifically, the second wall portion 222 is a flat, rectangular portion that protrudes in the negative Z-axis direction from the end of the first wall portion 221 in the positive Y-axis direction and is parallel to the XZ plane that extends in the X-axis direction. The second wall portion 222 is a long wall that is long in the X-axis direction.

[0051] The pair of third wall portions 223 are disposed at both ends in the X-axis direction of the first wall portion 221 and the second wall portion 222, and are plate-like portions facing the X-axis direction. Specifically, the third wall portion 223 is a flat, rectangular portion parallel to the YZ plane that protrudes in the negative Z-axis direction from the X-axis direction end of the first wall portion 221 and protrudes in the negative Y-axis direction from the X-axis direction end of the second wall portion 222. If the first wall portion 221 is an upper wall and the second wall portion 222 is a front wall, the third wall portion 223 is a side wall.

[0052] In this embodiment, the spacer protrusion 220 is integrally formed (integrally molded) with the spacer main body 210, but may be configured as a separate body from the spacer main body 210. The first wall 221, the second wall 222, and the third wall 223 are integrally formed (integrally molded) with other portions of the spacer protrusion 220, but may be configured as a separate body from other portions of the spacer protrusion 220.

[0053] The pair of legs 240 are legs of the spacer 200b that are located at both ends of the spacer 200b in the negative Z-axis direction. The pair of legs 240 protrude in the negative Z-axis direction from both ends of the spacer protrusion 220 in the X-axis direction. It can also be said that the legs 240 protrude in the negative Z-axis direction from both ends of the spacer main body 210 in the X-axis direction or from both ends of the pair of second spacer wall portions 232 in the X-axis direction. The legs 240 also protrude in the negative Z-axis direction from the spacer protrusion 220 (spacer main body 210). The legs 240 are placed on a step portion 311a of the bottom 311 of the exterior body 300 (described later) to support the spacer 200b relative to the exterior body 300. In this embodiment, the legs 240 protrude in the negative Z-axis direction beyond the spacer protrusion 220 (first wall portion 221, second wall portion 222, and third wall portion 223) (see FIG. 6 ). The shape and size of the leg portion 240 are not particularly limited as long as it is configured to support the spacer 200b.

[0054] The spacer 200b located at the end of the energy storage unit 10 in the negative direction on the Y axis has been described above, but the spacer 200b located at the end of the energy storage unit 10 in the positive direction on the Y axis also has a similar configuration. However, the spacer 200b located at the end of the energy storage unit 10 in the positive direction on the Y axis does not have the above-mentioned multiple convex portions 211 and spacer protrusion 220 (first wall portion 221, second wall portion 222, and third wall portion 223).

[0055] [1.3 Description of the Exterior Body Main Body 310 and Positional Relationships with Other Components] Next, the configuration of the exterior body main body 310 included in the exterior body 300 and the positional relationships between the exterior body main body 310, the energy storage elements 100, and the spacers 200 will be described in detail. FIG. 7 is a perspective view showing the configuration of the exterior body main body 310 according to the present embodiment. FIG. 8 is a cross-sectional view showing the positional relationships between the exterior body main body 310, the energy storage elements 100, and the spacers 200 according to the present embodiment. FIG. 8 shows a cross-section of the energy storage device 1 shown in FIG. 1 , with the lid 320 removed, taken at the end in the negative Y-axis direction, along a plane passing through line VIII-VIII and parallel to the YZ plane. In order to illustrate the space 212, FIG. 8 shows a cross-section of the configuration shown in FIG. 1 , taken at a position slightly shifted in the negative X-axis direction from the center position in the X-axis direction, where the protrusion 211 extends in the X-axis direction.

[0056] 7 , the exterior body main body 310 includes a bottom 311, a first exterior body wall 312, a second exterior body wall 313, and a pair of third exterior body walls 314. That is, the exterior body main body 310 includes the bottom 311 on the bottom surface facing the negative Z-axis direction, the first exterior body wall 312 on the front surface facing the negative Y-axis direction, the second exterior body wall 313 on the rear surface facing the positive Y-axis direction, and a pair of third exterior body walls 314 on both side surfaces in the X-axis direction. In the present embodiment, the exterior body main body 310 is a single member in which the bottom 311, the first exterior body wall 312, the second exterior body wall 313, and the pair of third exterior body walls 314 are integrated. That is, the exterior body main body 310 is integrally molded by aluminum die casting or the like and formed as a single member (one component).

[0057] The bottom 311 is a generally rectangular parallelepiped portion elongated in the Y-axis direction and located at the end of the exterior body main body 310 in the negative Z-axis direction. The bottom 311 is disposed in the negative Z-axis direction of the energy storage unit 10 so as to cover the entire surface of the energy storage unit 10 in the negative Z-axis direction, thereby supporting the energy storage unit 10 from the negative Z-axis direction. That is, as shown in FIG. 8 , the bottom 311 is disposed further in the negative Z-axis direction (on one side in the second direction) than the energy storage elements 100 and the spacers 200 (200a and 200b). The bottom 311 is disposed adjacent to the first exterior body wall 312, the second exterior body wall 313, and a pair of third exterior body wall portions 314. The bottom 311 includes a pair of step portions 311a, a bottom wall 311b, a second opening 311c, and an extension portion 311d.

[0058] The pair of step portions 311a are disposed at both ends of the bottom portion 311 in the X-axis direction and are stepped portions extending in the Y-axis direction. The pair of legs 240 of the spacer 200b are placed on the pair of step portions 311a, thereby supporting the spacer 200b. Similarly, the pair of step portions 311a of the spacer 200a are placed on the pair of legs (not shown) of the spacer 200a, thereby supporting the spacer 200a.

[0059] The bottom wall 311b is a wall disposed at the end of the bottom 311 in the negative Z-axis direction. In other words, the bottom wall 311b is the bottom wall of the exterior body main body 310 (the bottom wall of the exterior body 300). The bottom wall 311b is disposed with its main surface (the surface with the largest area) facing the Z-axis direction, forming the bottom surface of the exterior body main body 310. It is a flat, rectangular wall portion parallel to the XY plane and elongated in the Y-axis direction. As shown in FIG. 8 , the bottom wall 311b is disposed opposite the energy storage unit 10 (the energy storage elements 100 and the spacers 200 (200a and 200b)) in the Z-axis direction. The bottom wall 311b forms a space S between itself and the energy storage elements 100 and the spacers 200 (200a and 200b). The space S is a space located in the negative Z-axis direction within the internal space of the exterior body main body 310. That is, the space S is a space surrounded by the energy storage element 100, the spacer 200 (200a and 200b), the pair of step portions 311a, and the bottom wall 311b.

[0060] The second opening 311c is a rectangular through-hole that penetrates the wall of the bottom 311 in the negative Y-axis direction. The second opening 311c is an opening that connects the external space of the exterior body main body 310 with the space S inside the exterior body main body 310. The second opening 311c is an opening that allows a refrigerant to flow into the space S, for example, by being connected to a duct (not shown) that is connected to a blower (not shown) outside the exterior body main body 310. The refrigerant is a fluid such as a gas (air) that cools the energy storage element 100.

[0061] The extension portion 311d is a portion extending in the Y-axis direction (first direction) or the X-axis direction (third direction intersecting the first and second directions). That is, the extension portion 311d is a portion extending in the Y-axis direction (first direction) from an end portion of the bottom portion 311 in the Y-axis direction (first direction), or extending in the X-axis direction (third direction) from an end portion of the bottom portion 311 in the X-axis direction (third direction). In the present embodiment, the extension portion 311d is a plate-like portion extending in the Y-axis direction from an end portion of the bottom portion 311 in the Y-axis direction and extending in the X-axis direction from an end portion of the bottom portion 311 in the X-axis direction. Specifically, the extension portion 311d is a flat, rectangular wall portion that is parallel to the XY plane and elongated in the X-axis direction, extending in the Y-axis positive direction (one side in the first direction) from an end portion of the second opening 311c in the Z-axis positive direction and extending in the X-axis direction along the end portion of the second opening 311c in the Z-axis positive direction. That is, both ends of the extension portion 311d in the X-axis direction are connected to the pair of step portions 311a, the extension portion 311d protrudes from the second opening 311c parallel to the bottom wall 311b, and is disposed opposite the bottom wall 311b. As a result, the extension portion 311d, together with the pair of step portions 311a and the bottom wall 311b, forms a flow path (a flow path at the inlet of the exterior body 310) for the refrigerant flowing in from the second opening 311c. The extension portion 311d may be configured to support the spacer 200b by having the spacer 200b placed on it.

[0062] 8 , the spacer protrusion 220 (first wall 221, second wall 222, and third wall 223) of the spacer 200b is disposed within the space S. The first wall 221 of the spacer protrusion 220 extends in the positive Y-axis direction (one side of the first direction) that faces the energy storage device 100. The second wall 222 extends in the negative Z-axis direction that faces away from the energy storage device 100. In this configuration, the extension 311d is disposed between the bottom wall 311b and the spacer protrusion 220 when viewed from the Y-axis direction (first direction). That is, the extension 311d is disposed between the bottom wall 311b and the first wall 221, the second wall 222, and the third wall 223 when viewed from the Y-axis direction (first direction). Specifically, the extension portion 311d is disposed in the negative Z-axis direction of the spacer protrusion 220 (the first wall portion 221, the second wall portion 222, and the third wall portion 223). Furthermore, the extension portion 311d is disposed to protrude in the positive Y-axis direction further than the spacer protrusion 220. In other words, the extension portion 311d protrudes in the positive Y-axis direction (one side in the first direction) further than the first wall portion 221, the second wall portion 222, and the third wall portion 223.

[0063] The first exterior body wall 312 and the second exterior body wall 313 are short side walls of the exterior body main body 310 (short side walls of the exterior body 300). The first exterior body wall 312 and the second exterior body wall 313 are arranged with their main surfaces (the surfaces with the largest areas) facing the Y axis direction, and are flat, rectangular wall portions (short side walls) parallel to the XZ plane that form side surfaces (short side surfaces) in the Y axis direction of the exterior body main body 310. The first exterior body wall 312 and the second exterior body wall 313 are wall portions that rise in the positive direction of the Z axis from both ends of the bottom 311 in the Y axis direction, and are arranged opposite the energy storage unit 10 (spacer 200b) in the Y axis direction. The first exterior body wall 312 is adjacent to the bottom 311 and the pair of third exterior body walls 314.

[0064] The pair of third exterior body walls 314 are the long side walls of the exterior body main body 310 (the long side walls of the exterior body 300). The pair of third exterior body walls 314 are arranged with their main surfaces (the surfaces with the largest areas) facing the X axis direction, and are flat, rectangular wall portions (long side walls) that are parallel to the YZ plane and elongated in the Y axis direction, forming the side surfaces (long sides) of the exterior body main body 310 in the X axis direction. The pair of third exterior body walls 314 are wall portions that rise in the positive direction of the Z axis from both ends of the bottom 311 in the X axis direction, and are arranged opposite the energy storage unit 10 (the energy storage elements 100 and the spacers 200 (200a and 200b)) in the X axis direction. The pair of third exterior body walls 314 are adjacent to the bottom 311, the first exterior body wall portion 312, and the second exterior body wall portion 313.

[0065] With the above configuration, the exterior body main body 310 has a first opening 310a that opens in the positive direction of the Z axis. That is, the first opening 310a is formed by the first exterior body wall 312, the second exterior body wall 313, and the pair of third exterior body wall portions 314. The first opening 310a is a rectangular opening that is long in the Y axis direction when viewed from the Z axis direction, and is located at a position opposite the bottom 311 of the exterior body main body 310. The first opening 310a is formed to a size that allows the energy storage unit 10 to pass through in the Z axis direction. That is, the first opening 310a is an opening that is open on the surface of the exterior body main body 310 that is in the positive direction of the Z axis.

[0066] [2 Description of Effects] As described above, in the energy storage device 1 according to the present embodiment, the spacer protrusion 220 of the spacer 200b protruding in the negative Z-axis direction (one side in the second direction) includes the first wall 221. The first wall 221 is disposed in the space S between the bottom wall 311b of the bottom 311 of the exterior body 300 and the energy storage device 100 and the spacer 200b, and extends in the positive Y-axis direction (one side in the first direction), which is the direction toward the energy storage device 100. In this case, a gap is formed between the energy storage device 100 and the first wall 221. Since the spacer protrusion 220 includes the first wall 221 in the space S, when a refrigerant such as air flows through the space S, the refrigerant heading toward the spacer protrusion 220 is more likely to flow toward the spacer main body 210 (the energy storage device 100) due to the first wall 221. This point will be described in detail below. 9 is a cross-sectional view showing a state in which the refrigerant F flows within the space S of the exterior body 310 according to this embodiment. FIG. 9 illustrates the flow of the refrigerant F in FIG.

[0067] As shown in FIG. 9 , the refrigerant F that flows into the exterior body main body 310 from the second opening 311c flows in the space S along the extension portion 311d in the positive direction of the Y axis. Thereafter, as shown in FIG. 9 , the refrigerant F flows in the positive direction of the Y axis, sequentially cooling the energy storage elements 100. When the refrigerant F1 reaches the end of the exterior body main body 310 in the positive direction of the Y axis, it turns toward the negative direction of the Y axis at the second exterior body wall portion 313 and becomes refrigerant F2, which flows in the negative direction of the Y axis. While flowing in the negative direction of the Y axis, the refrigerant F2 flows into the space between the spacer 200a and the energy storage elements 100, cooling the energy storage elements 100. The refrigerant F2 then reaches the spacer 200b at the end in the negative direction of the Y axis. As a result, the refrigerant F1 cools the energy storage elements 100 at the end in the negative direction of the Y axis, and the refrigerant F2 cools the energy storage elements 100 at the end in the negative direction of the Y axis. In this case, if the spacer 200b did not have the first wall portion 221, the refrigerant F2 would hit the lower part of the spacer main body 210 or the upper part of the spacer protrusion 220, and then flow in the negative direction of the Z axis. In contrast, by providing the spacer 200b with the first wall portion 221, the branch point where the refrigerant F2 hits the spacer 200b can be lowered to the position of the first wall portion 221, making it easier for the refrigerant F2 to flow in the positive direction of the Z axis. As a result, the refrigerant F2 flows into the space 212 between the spacer main body 210 of the spacer 200b and the energy storage element 100, and cools the energy storage element 100. As a result, the energy storage device 1 can improve the cooling performance of the energy storage element 100.

[0068] In a configuration in which the spacer protrusion 220 and the spacer main body 210 are integrally molded, the positional accuracy of the spacer main body 210 relative to the spacer protrusion 220 is higher than in a configuration in which the spacer protrusion 220 and the spacer main body 210 are assembled as separate bodies. That is, the positional accuracy of the spacer main body 210 relative to the first wall portion 221 is higher. As a result, the refrigerant F2 efficiently flows from the first wall portion 221 into the space 212 between the spacer main body 210 of the spacer 200b and the energy storage elements 100, and efficiently cools the energy storage elements 100. As a result, the energy storage device 1 can further improve the cooling performance of the energy storage elements 100.

[0069] The spacer protrusion 220 of the spacer 200b includes a second wall 222 extending in the negative Z-axis direction (one side in the second direction) from the first wall 221. This allows the second wall 222 to gradually narrow the flow path of the refrigerant flowing toward the first wall 221, making it easier for the refrigerant to flow toward the spacer main body 210 (energy storage element 100).

[0070] The bottom 311 of the exterior body 300 has an extension 311d extending in the positive direction of the Y axis (one side of the first direction) between the bottom wall 311b and the first wall 221. When the bottom 311 has the extension 311d in this way, it may be difficult for the refrigerant, such as air, to flow toward the spacer main body 210 (energy storage device 100). In such cases, it is highly effective to provide the first wall 221 on the spacer protrusion 220 to make it easier for the refrigerant to flow toward the spacer main body 210 (energy storage device 100).

[0071] The extension 311d of the bottom 311 of the exterior body 300 protrudes in the positive Y-axis direction (one side in the first direction) beyond the first wall 221, making it even more difficult for the refrigerant to flow toward the spacer main body 210 (energy storage elements 100). Therefore, providing the first wall 221 on the spacer protruding portion 220 further enhances the effect of making it easier for the refrigerant to flow toward the spacer main body 210 (energy storage elements 100).

[0072] Since the spacer 200b is an end spacer, the refrigerant does not easily flow toward the spacer main body 210 (energy storage device 100). Therefore, providing the first wall portion 221 on the spacer protrusion 220 is highly effective in making it easier for the refrigerant to flow toward the spacer main body 210 (energy storage device 100).

[0073] [3 Description of Modifications] While the energy storage device 1 according to the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. The embodiment disclosed herein is an example in all respects, and the scope of the present invention includes all modifications within the meaning and scope of the claims.

[0074] (Variations 1 and 2) In the above embodiment, the spacer protrusion 220 (first wall portion 221, second wall portion 222, and third wall portion 223) of the spacer 200b may have various shapes. The first wall portion 221 may be curved rather than flat, and its length in the X-axis direction, width in the Y-axis direction, and thickness in the Z-axis direction are not limited. The second wall portion 222 may be curved rather than flat, and its length in the X-axis direction, width in the Z-axis direction, and thickness in the Y-axis direction are not limited. One or both of the pair of third wall portions 223 may not be provided. Other possible configurations include the following. FIG. 10 is a cross-sectional view showing the configuration of the spacer protrusion 220a of the spacer 200 (spacer 200c) according to Variation 1 of this embodiment. FIG. 11 is a cross-sectional view showing the configuration of the spacer protrusion 220b of the spacer 200 (spacer 200d) according to Variation 2 of this embodiment. FIGS. 10 and 11 correspond to FIG. 6.

[0075] As shown in FIG. 10 , the spacer 200c of the first modification includes a spacer protrusion 220a instead of the spacer protrusion 220 of the spacer 200b of the above embodiment. The spacer protrusion 220a includes a second wall 222a instead of the second wall 222 of the spacer protrusion 220. The second wall 222a is a portion extending from the first wall 221 in a direction inclined from the negative Z-axis direction (one side of the second direction). Specifically, the second wall 222a is a plate-shaped portion extending from the end of the first wall 221 in the positive Y-axis direction in a direction inclined from the negative Z-axis direction to the positive Y-axis direction. The remaining configuration of this modification is similar to that of the above embodiment, and therefore will not be described again.

[0076] This modification can achieve the same effects as the above-described embodiment. In particular, in this modification, the spacer protrusion 220a of the spacer 200c includes a second wall portion 222a extending from the first wall portion 221 in a direction inclined from the negative Z-axis direction (one side of the second direction). This allows the second wall portion 222a to gradually narrow the flow path of the refrigerant flowing toward the first wall portion 221, making it easier for the refrigerant to flow toward the spacer main body 210 (energy storage device 100). The second wall portion 222a can guide the refrigerant toward the spacer main body 210 (energy storage device 100), making it easier to guide the refrigerant into the space between the spacer main body 210 and the energy storage device 100. This further improves the cooling performance of the energy storage device 100.

[0077] As shown in FIG. 11 , a spacer 200d in Modification 2 includes a spacer protrusion 220b instead of the spacer protrusion 220 of the spacer 200b in the above embodiment. The spacer protrusion 220b does not include the second wall 222 and the third wall 223 of the spacer protrusion 220. The other configurations of this modification are similar to those of the above embodiment, and therefore description thereof will be omitted. Since this modification also includes the spacer protrusion 220b and the first wall 221, it is possible to achieve the same effects as the above embodiment. In particular, since the spacer 200d in this modification does not include the second wall 222 and the third wall 223 of the above embodiment, the configuration can be simplified.

[0078] (Other Modifications) In the above embodiment, the spacer 200b located at the end in the positive direction of the Y axis of the energy storage unit 10 does not include the plurality of convex portions 211 and the spacer protruding portion 220 (the first wall portion 221, the second wall portion 222, and the third wall portion 223), but may include some or all of these. Similarly, the exterior body 300 does not include the second opening 311c and the extension portion 311d at the end in the positive direction of the Y axis, but may include at least one of the second opening 311c and the extension portion 311d at the end in the positive direction of the Y axis.

[0079] In the above embodiment, the extension 311d of the bottom 311 of the exterior body 300 protrudes in the positive direction of the Y axis beyond the first wall 221 of the spacer protrusion 220, but it does not have to protrude from the first wall 221. Alternatively, the bottom 311 does not have to have the extension 311d.

[0080] In the above embodiment, the spacer 200b is an end spacer, but it does not have to be an end spacer. That is, the spacer 200a may have a configuration similar to that of the spacer protrusion 220 of the spacer 200b.

[0081] In the above embodiment, the spacer wall portion 230 of the spacer 200b includes a pair of first spacer wall portions 231, a pair of second spacer wall portions 232, a pair of third spacer wall portions 233, and a pair of fourth spacer wall portions 234. However, the spacer 200b is not limited to including all of these wall portions. The spacer 200b may be a holder that holds the energy storage elements 100 by including at least one of these wall portions, or may be a plate-shaped spacer that does not have all of the wall portions (does not hold the energy storage elements 100).

[0082] In the above embodiment, the spacer body 210 of the spacer 200b has the plurality of protrusions 211 shown in Fig. 5, but there are no particular limitations on the number, size, or shape of the protrusions 211. The spacer body 210 does not have to have the protrusions 211. This also makes it possible to cool the energy storage elements 100 by flowing a refrigerant through the space between the spacer 200b and the energy storage elements 100.

[0083] In the above embodiment, the spacers 200 (200a and 200b) are arranged alternately with the energy storage elements 100 in the Y-axis direction, but a configuration in which none of the spacers 200 is arranged may be used. A configuration in which only one spacer 200b is arranged may also be used.

[0084] In the above embodiment, the height of the exterior body main body 310 in the Z-axis direction is not particularly limited. That is, the exterior body main body 310 may be configured to have a sufficient height in the Z-axis direction to accommodate the power storage unit 10, so that the power storage unit 10 does not protrude from the exterior body main body 310 in the positive direction of the Z-axis. The exterior body main body 310 may have a height of about two-thirds or half of the power storage unit 10 in the Z-axis direction, to accommodate a portion of the power storage unit 10 in the negative direction of the Z-axis, and to expose a portion of the power storage unit 10 in the positive direction of the Z-axis. In this case, the lid 320 may have a height of about one-third or half of the power storage unit 10 in the Z-axis direction, so as to accommodate a portion of the power storage unit 10 in the positive direction of the Z-axis.

[0085] In the above embodiment, a plurality of power storage units 10 aligned in the X-axis direction may be housed inside the exterior body 300. A plurality of power storage units 10 aligned in the Y-axis direction may be housed inside the exterior body 300. When a plurality of power storage units 10 are housed in the exterior body 300, the above-described configuration may be provided for each of the plurality of power storage units 10, or the above-described configuration may not be provided for any of the power storage units 10.

[0086] In the above embodiment, the exterior body 300 includes the exterior body main body 310 and the lid body 320, but the lid body 320 may not be included.

[0087] In the above embodiment, the energy storage unit 10 may include restraining members (end plates, side plates, etc.) that restrain the plurality of energy storage elements 100 and the spacers 200 .

[0088] Any combination of the components of the above-described embodiment and its modifications is also included within the scope of the present invention.

[0089] 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.

[0090] REFERENCE SIGNS LIST 1 Energy storage device 10 Energy storage unit 100 Energy storage element 110 Container 140 Terminal 200, 200a, 200b, 200c, 200d Spacer 210 Spacer main body 211 Convex portion 220, 220a, 220b Spacer protrusion 221 First wall portion 222, 222a Second wall portion 223 Third wall portion 230 Spacer wall portion 240 Leg portion 300 Exterior body 310 Exterior body main body 310a First opening 311 Bottom portion 311a Step portion 311b Bottom wall 311c Second opening 311d Extension portion 312 First exterior body wall portion 313 Second exterior body wall portion 314 Third exterior body wall portion 320 Lid

Claims

1. An energy storage device comprising: an energy storage element; a spacer; and an exterior body, wherein the spacer comprises: a spacer main body facing the energy storage element in a first direction which is the alignment direction of the energy storage element and the spacer; and a spacer protrusion protruding from the spacer main body to one side in a second direction which is a direction intersecting the first direction, wherein the exterior body comprises a bottom portion on the one side in the second direction of the energy storage element and the spacer, wherein the bottom portion comprises a bottom wall which forms a space between the energy storage element and the spacer, and wherein the spacer protrusion is disposed in the space and comprises a first wall portion extending to one side in the first direction which is the direction facing the energy storage element.

2. The energy storage device according to claim 1, wherein the spacer protrusion further comprises a second wall portion extending from the first wall portion toward the one side in the second direction or in a direction inclined from the one side in the second direction.

3. The energy storage device according to claim 1 or 2, wherein the bottom portion is disposed between the bottom wall and the first wall portion when viewed from the first direction, and further comprises an extension portion extending to the one side in the first direction.

4. The energy storage device according to claim 3, wherein the extension portion protrudes further to the one side in the first direction than the first wall portion.

5. The energy storage device according to claim 1 or 2, wherein the spacer is an end spacer located furthest to the other side in the first direction among a plurality of spacers included in the energy storage device.

Images