Power storage device

Abstract

This power storage device comprises: a power storage element; a spacer; and a bus bar arranged side by side with the power storage element in a direction intersecting the arrangement direction of the power storage element and the spacer.

Description

Power storage device

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

[0002] Patent Document 1 discloses a power supply device that includes a plurality of battery cells, conductive bus bars that connect the electrode terminals of adjacent battery cells, and an insulating bus bar holder that is fixed to the upper surface of a battery stack in which the plurality of battery cells are stacked and that positions the bus bars.

[0003] JP 2015-207340 A

[0004] In the power supply device disclosed in the above-mentioned Patent Document 1, a bus bar holder is used to position the bus bar, and spacers are also placed between multiple battery cells, but it is preferable that the power supply device can be configured simply.

[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 a power storage device with a simple configuration.

[0006] An energy storage device according to one embodiment of the present invention comprises an energy storage element, a spacer, and a bus bar arranged alongside the energy storage element in a direction intersecting the arrangement direction of the energy storage element and the spacer, one of the spacer and the bus bar having a protrusion, and the other of the spacer and the bus bar having an opening into which the protrusion is inserted.

[0007] Another aspect of the present invention provides an energy storage device comprising an energy storage element, a spacer, a bus bar arranged alongside the energy storage element in a direction intersecting the arrangement direction of the energy storage element and the spacer, and a bus bar cover covering the bus bar, wherein the spacer holds the bus bar cover.

[0008] According to the electricity storage device of the present invention, the electricity storage device can have a simple configuration.

[0009] 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 a configuration of an energy storage unit according to an embodiment. FIG. 3 is an exploded perspective view showing configurations of energy storage elements and a spacer 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 bus bar according to an embodiment. FIG. 6 is a perspective view showing a configuration in which a spacer according to an embodiment positions a bus bar and holds a bus bar cover. FIG. 7 is a plan view showing a configuration in which a spacer according to an embodiment positions a bus bar. FIG. 8 is a plan view showing a configuration in which a spacer according to a first modification of the embodiment positions a bus bar. FIG. 9 is a plan view showing a configuration in which a spacer according to a second modification of the embodiment positions a bus bar.

[0010] (1) An energy storage device according to one aspect of the present invention comprises an energy storage element, a spacer, and a bus bar arranged alongside the energy storage element in a direction intersecting the arrangement direction of the energy storage element and the spacer, wherein one of the spacer and the bus bar has a protrusion, and the other of the spacer and the bus bar has an opening into which the protrusion is inserted.

[0011] In the energy storage device according to one aspect of the present invention, one of the spacer and the busbar has a protrusion, and the other of the spacer and the busbar has an opening, so that the busbar can be positioned by the spacer by inserting the protrusion into the opening. This allows the spacer to be used to position the busbar in the energy storage device, thereby simplifying the configuration of the energy storage device.

[0012] (2) In the energy storage device described in (1) above, the protrusion may protrude in a direction intersecting an arrangement direction of the energy storage elements and the bus bars.

[0013] According to the energy storage device described in (2) above, the protrusions protrude in a direction intersecting the arrangement direction of the energy storage elements and the bus bars. As a result, the protrusions are inserted into the openings in the intersecting direction, allowing the bus bars to be positioned by the spacers.

[0014] (3) In the energy storage device described in (1) or (2) above, the spacer may include a first spacer and a second spacer that sandwich the energy storage element, one of the first spacer and the bus bar having a first protrusion, the other of the first spacer and the bus bar having a first opening into which the first protrusion is inserted, one of the second spacer and the bus bar having a second protrusion, and the other of the second spacer and the bus bar having a second opening into which the second protrusion is inserted.

[0015] According to the energy storage device described in (3) above, one of the first spacer and the bus bar includes a first protrusion, and the other of the first spacer and the bus bar includes a first opening, and one of the second spacer and the bus bar includes a second protrusion, and the other of the second spacer and the bus bar includes a second opening. Thus, by inserting the first protrusion into the first opening and the second protrusion into the second opening, the bus bar can be positioned by the first spacer and the second spacer. Therefore, in the energy storage device, the bus bar can be positioned using two spacers (the first spacer and the second spacer), and the bus bar can be stably positioned with a simple configuration.

[0016] (4) The energy storage device according to any one of (1) to (3) above may further include a bus bar cover that covers the bus bar, and the spacer may hold the bus bar cover.

[0017] According to the energy storage device described in (4) above, the spacer holds the bus bar cover. This allows the spacer to be used to hold the bus bar cover in the energy storage device, further simplifying the configuration of the energy storage device.

[0018] (5) In the energy storage device described in (4) above, the spacer may include a third spacer and a fourth spacer that sandwich the energy storage element, and the third spacer and the fourth spacer may hold the bus bar cover.

[0019] According to the energy storage device described in (5) above, the third spacer and the fourth spacer hold the bus bar cover, so that the bus bar cover can be held using two spacers (the third spacer and the fourth spacer), and therefore the bus bar cover can be stably held with a simple configuration.

[0020] (6) Another aspect of the present invention provides an energy storage device comprising an energy storage element, a spacer, a bus bar arranged alongside the energy storage element in a direction intersecting the arrangement direction of the energy storage element and the spacer, and a bus bar cover covering the bus bar, wherein the spacer holds the bus bar cover.

[0021] In the energy storage device according to another aspect of the present invention, the spacer holds the bus bar cover. This allows the spacer to be used to hold the bus bar cover in the energy storage device, thereby simplifying the configuration of the energy storage device.

[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 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.

[0023] In the following description and drawings, the X-axis direction is defined as the arrangement direction of a pair of terminals (positive and negative electrodes) of an energy storage element, or the direction in which a pair of short side surfaces of a container for one energy storage element face each other. The Y-axis direction is defined as the arrangement direction of multiple energy storage elements, the arrangement direction of multiple spacers, the arrangement direction of an energy storage element and a spacer, the thickness (narrowest width) direction of an energy storage element, the thickness (narrowest width) direction of a spacer, or the direction in which a pair of long side surfaces of a container for one energy storage element face each other. The Z-axis direction is defined as the arrangement direction of an energy storage element and a bus bar, the arrangement direction of a bus bar and a bus bar cover, the protruding direction of terminals of the energy storage element, the arrangement direction of a container body and a container lid for the energy storage element, the arrangement direction of a container body and a lid for 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.

[0024] In the following description, the positive X-axis direction refers to the direction of the arrow on the X-axis, 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, it refers to both or either of the positive X-axis direction and the negative X-axis direction. The same applies to the Y-axis direction and the Z-axis direction. Expressions indicating relative directions or attitudes, such as parallel and orthogonal, also include cases where the directions or attitudes are not strictly those. When two directions are parallel (or orthogonal), it does not only mean that the two directions are completely parallel (or orthogonal), but also means that the directions are substantially parallel (or orthogonal), that is, there is a difference of, for example, about several percent. In the following description, when the term "insulation" is used, it means "electrical insulation". An insulating material has a volume resistivity of 1×10 ６ Ωm or more, more preferably 1×10 ７ Ωm or more, more preferably 1×10 １０ It is preferable that the material be made of a material with a resistance of Ωm or more.

[0025] (Embodiment) [1. Outline of Energy Storage Device 1] First, a schematic configuration of an energy storage device 1 according to the present embodiment will be described. FIG. 1 is a perspective view showing the configuration of the energy storage device 1 according to the present embodiment. FIG. 1 shows a state in which the cover 520 is removed from the exterior body main body 510 of the exterior body 500 in the energy storage device 1, and the energy storage unit 10 is taken out. Thus, FIG. 1 shows the energy storage unit 10 arranged inside the exterior body 500. FIG. 2 is an exploded perspective view showing the configuration of the energy storage unit 10 according to the present embodiment. FIG. 2 shows a state in which the bus bar 300 and the bus bar cover 400 are removed from the energy storage elements 100 and the spacer 200 included in the energy storage unit 10. FIG. 3 is an exploded perspective view showing the configuration of the energy storage elements 100 and the spacer 200 according to the present embodiment. FIG. 3 illustrates four energy storage elements 100 and two spacers 210, two spacers 220, and one spacer 230 included in the spacer 200, as the energy storage elements 100 and spacers 200 included in the energy storage unit 10.

[0026] The power storage device 1 is a device capable of charging with electricity from an external source and discharging electricity to an external source. In this embodiment, the power storage device 1 has a rectangular parallelepiped shape. A rectangular parallelepiped is a hexahedron with all faces formed as rectangles or squares. The power storage device 1 is used for power storage, power supply, or other purposes. Specifically, 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 an electric railway include an electric train, a monorail, a linear motor car, and a hybrid electric 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.

[0027] 1 , the energy storage device 1 includes an energy storage unit 10 and an exterior body 500 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, as well as an exhaust unit that exhausts gas from inside the exterior body 500.

[0028] The exterior body 500 is a rectangular parallelepiped (box-shaped) container (module case) that constitutes the exterior body (housing, outer shell) of the energy storage device 1. The exterior body 500 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 500 is formed of 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. The exterior body 500 thereby prevents the energy storage unit 10 from coming into contact with external metal members and the like. As long as the insulation properties of the power storage unit 10 can be ensured, the exterior body 500 may be a metal case made of a metal member such as aluminum, an aluminum alloy, stainless steel, iron, or plated steel sheet.

[0029] The exterior body 500 includes an exterior body main body 510 that constitutes the main body of the exterior body 500, and a lid body 520 that constitutes the lid body of the exterior body 500. The exterior body main body 510 is a housing (chassis) with an opening 511 that opens in the positive direction of the Z axis, and houses the energy storage unit 10. The lid body 520 is a flat, rectangular member that closes the opening 511 of the exterior body main body 510. The rectangular opening 511 is formed in the exterior body main body 510, and after the energy storage unit 10 is inserted through the opening 511, the exterior body main body 510 and the lid body 520 are joined by screwing with bolts or the like, welding, adhesive, or the like. This results in the exterior body 500 having a structure in which the interior is sealed (sealed). The exterior body main body 510 and the lid body 520 may be formed of members of the same material or members of different materials.

[0030] The energy storage unit 10 is a battery module (battery assembly) including a plurality of energy storage elements. As shown in Figures 2 and 3 , the energy storage unit 10 includes a plurality of energy storage elements 100, a spacer 200, a bus bar 300, and a bus bar cover 400. The energy storage unit 10 also includes bus bars and the like that connect the energy storage elements 100 to external terminals, but these are not shown. The energy storage unit 10 may also include restraining members (end plates, side plates, etc.) that restrain the plurality of energy storage elements 100 and the spacer 200 in the Y-axis direction.

[0031] 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 (rectangular) shape that is flattened in the Y-axis direction. In this embodiment, four energy storage elements 100 are arranged side by side in the Y-axis direction, but the number of energy storage elements 100 arranged is not particularly limited and may be one. 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 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. The configuration of the energy storage element 100 will be described in detail later.

[0032] 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 heat between the energy storage element 100 and other components. The spacer 200 is an insulating or heat-insulating plate that is arranged in the positive or negative Y-axis direction of the energy storage element 100 and provides insulation and / or heat between the energy storage elements 100 and each other or between the energy storage element 100 and the exterior body 500. 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 holding the energy storage element 100 and also functioning as a holder that positions the energy storage element 100. The spacer 200 is formed from an insulating member such as any resin material that can be used for the exterior body 500, or a heat-insulating member such as mica.

[0033] The spacer 200 includes two spacers 210, two spacers 220, and one spacer 230. The two spacers 210 are spacers among the spacers 200 that are 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 500). The spacer 230 is a spacer among the spacers 200 that is arranged at a central position of the energy storage unit 10 in the Y-axis direction (between the two energy storage elements 100 at the central positions). The two spacers 220 are spacers among the spacers 200 that are arranged between the two spacers 210 and the spacer 230. In other words, in the Y-axis direction, two spacers 220 are arranged between two spacers 210, and one spacer 230 is arranged between two spacers 220. These spacers 210, spacers 220, and spacers 230 are arranged alternately with the energy storage elements 100 in the Y-axis direction.

[0034] Specifically, spacer 210 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 that is arranged on one side of spacer 210 in the Y-axis direction, and that holds the one energy storage element 100. Spacer 220 is an intermediate spacer (intermediate 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 that are arranged on both sides of spacer 220 in the Y-axis direction, and that holds the two energy storage elements 100. Similarly, spacer 230 is an intermediate spacer (intermediate 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 that are arranged on both sides of spacer 230 in the Y-axis direction, and that holds the two energy storage elements 100.

[0035] That is, the two energy storage elements 100 located in the center of the energy storage unit 10 in the Y-axis direction are held by the spacers 220 and 230. The two energy storage elements 100 located at the ends of the energy storage unit 10 in the Y-axis direction are held by the spacers 210 and 220. The energy storage elements 100 may be configured to be held by only one spacer 210, only one spacer 220, or only one spacer 230. The spacers 210, 220, and 230 may all be formed of the same material, or any of them may be formed of different materials. A detailed description of the configuration of the spacers 200 (spacers 210, 220, and 230) will be given later.

[0036] The bus bar 300 is a plate-like, substantially rectangular member that is disposed on the plurality of energy storage elements 100 and electrically connects the terminals 120 of the plurality of energy storage elements 100 to one another. The bus bar 300 is disposed alongside the energy storage elements 100 in a direction (Z-axis direction) that intersects with the arrangement direction (Y-axis direction) of the energy storage elements 100 and the spacers 200. In the present embodiment, the bus bar 300 is joined to the terminals 120 of the energy storage elements 100 by welding, but may also be joined to the terminals 120 by a method other than welding, such as bolt fastening. The bus bar 300 is formed from a conductive member made of a metal such as aluminum, an aluminum alloy, copper, a copper alloy, or nickel, or a combination thereof, or a conductive member other than a metal.

[0037] The bus bar 300 includes a bus bar 310, a bus bar 320, and a bus bar 330. The bus bar 310 is connected to the terminals 120 of the two energy storage elements 100 arranged at the ends in the positive direction of the Y axis, facing in the negative direction of the X axis. The bus bar 320 is connected to the terminals 120 of the two energy storage elements 100 arranged at the ends in the negative direction of the Y axis, facing in the negative direction of the X axis. The bus bar 330 is connected to the terminals 120 of the two energy storage elements 100 arranged in the center in the Y axis direction, facing in the positive direction of the X axis. In this embodiment, the bus bars 310, 320, and 330 connect the terminals 120 of opposite polarities to each other, thereby connecting the four energy storage elements 100 in series. The bus bar 300 may connect some of the energy storage elements 100 in parallel and then connect them in series, or it may connect all of the energy storage elements 100 in parallel. A detailed description of the configuration of the bus bar 300 will be given later.

[0038] The bus bar cover 400 is a plate-like, substantially rectangular member that covers the bus bar 300. The bus bar cover 400 is formed from any insulating or heat-insulating material that can be used for the spacer 200. In the present embodiment, the bus bar cover 400 is disposed in the positive Z-axis direction of all bus bars 300 (310, 320, and 330) included in the energy storage unit 10, and covers all of these bus bars 300 in the positive Z-axis direction. Specifically, the bus bar cover 400 is disposed on top of the energy storage unit 10, and covers the upper sides of all of the energy storage elements 100 included in the energy storage unit 10 (see FIG. 1 ). In this way, the bus bar cover 400 insulates the bus bar 300 and the energy storage elements 100 (terminals 120) from components (such as a substrate) above the bus bar cover 400. The busbar cover 400 also has the function of preventing gas generated from the energy storage element 100 from directly hitting components (substrates, etc.) above the busbar cover 400, and of preventing heat from the busbar 300 and the energy storage element 100 from being transferred to those components.

[0039] The bus bar cover 400 includes a cover body 410 and cover protrusions 420. The cover body 410 is the main body of the bus bar cover 400 and is a flat, rectangular portion. The cover protrusions 420 are convex portions protruding from the cover body 410. In this embodiment, two cover protrusions 420 protruding in the positive X-axis direction are arranged side by side in the Y-axis direction at the end of the cover body 410 facing the positive X-axis direction, and two cover protrusions 420 protruding in the negative X-axis direction are arranged side by side in the Y-axis direction at the end of the cover body 410 facing the negative X-axis direction. These four cover protrusions 420 are inserted into openings formed in the spacer 200, thereby attaching and holding the bus bar cover 400 to the spacer 200. A detailed description of the configuration in which the bus bar cover 400 is held by the spacer 200 will be provided later.

[0040] [2 Description of Energy Storage Element 100] Next, a detailed description will be given of the configuration of the energy storage element 100. Since the multiple energy storage elements 100 included in the energy storage unit 10 all have the same configuration, the following will describe in detail the configuration of one energy storage element 100.

[0041] As shown in FIG. 3 , the energy storage element 100 includes a container 110 and a pair of terminals 120 (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 120 and current collectors and the container 110, but these are not shown (the gaskets are only partially illustrated). The type of electrolyte is not particularly limited 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.

[0042] The container 110 is a rectangular parallelepiped (square or box-shaped) case including a container body 111 with an opening formed therein and a container lid 112 that closes the opening of the container body 111. The container body 111 is a rectangular cylindrical member with a bottom that constitutes the main body of the container 110. The container lid 112 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 111. The container lid 112 is provided with a gas exhaust valve 113 that releases pressure inside the container 110 if the pressure inside the container 110 increases excessively, a liquid injection part 114 that injects electrolyte into the container 110, and the like. The material of the container 110 (the container body 111 and the container lid 112) is not particularly limited and can be a weldable (joinable) metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel plate, but resin can also be used.

[0043] After the electrode assembly and the like are housed inside the container body 111, the container body 111 and the container lid 112 are joined by welding or the like, thereby sealing the interior of the container 110. The container 110 has a pair of long sides on both sides in the Y-axis direction, a pair of short sides on both sides in the X-axis direction, and a bottom surface in the negative Z-axis direction. The long sides are rectangular flat portions and are arranged opposite adjacent spacers 200 in the Y-axis direction. The short sides are rectangular flat portions and are arranged opposite the wall portions of the spacers 200 and the exterior body 500 in the X-axis direction. The bottom surface is a rectangular flat portion and is arranged opposite the wall portions of the spacers 200 and the bottom wall of the exterior body 500 in the Z-axis direction.

[0044] The terminals 120 are electrode terminals (positive and negative terminals) of the energy storage element 100 that are disposed on the container lid 112. The terminals 120 are disposed in a state that protrudes from the upper surface (terminal arrangement surface) of the container lid 112 in the positive direction of the Z axis. The terminals 120 are electrically connected to the positive and negative electrode plates of the electrode assembly via current collectors. In other words, the terminals 120 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 120 are formed of aluminum, an aluminum alloy, copper, a copper alloy, or the like.

[0045] 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.

[0046] The current collectors are conductive current collecting members (positive and negative current collectors) electrically and mechanically connected to the terminal 120 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.

[0047] [3 Description of Spacer 200] Next, the configuration of the spacer 200 (spacer 210, spacer 220, and spacer 230) will be described in detail. The two spacers 210 provided in the energy storage unit 10 are rotated 180° about the Z axis and have the same configuration. The two spacers 220 provided in the energy storage unit 10 have the same configuration. Therefore, one spacer 210, one spacer 220, and one spacer 230 will be illustrated below, and their configurations will be described in detail. FIG. 4 is a perspective view showing the configurations of the spacers 210, 220, and 230 according to this embodiment. FIG. 4 illustrates an enlarged view of the spacer 210 in the positive direction of the Y axis, the spacer 220 in the positive direction of the Y axis, and the spacer 230 shown in FIG. 3, and further enlarged views of portions thereof.

[0048] 4, the spacer 210 has a shape in which the positive half of the spacer 210 in the X-axis direction and the negative half of the spacer 210 in the X-axis direction have the same shape. In other words, the spacer 210 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 210 includes a spacer main body 211, a spacer wall portion 211a, and spacer protrusions 212 and 213.

[0049] The spacer main body 211 is a flat, rectangular portion that constitutes the main body of the spacer 210 and is disposed parallel to the XZ plane. The spacer main body 211 is a portion that faces the energy storage element 100 in the Y-axis direction. Specifically, the spacer main body 211 faces the container 110 of the energy storage unit 10 in the Y-axis direction. The spacer main body 211 is disposed in a state that faces the long side surface of the container 110 of the energy storage element 100 in the Y-axis direction and is in contact with the long side surface so as to cover the entire long side surface of the container 110 of the energy storage element 100.

[0050] The spacer wall portions 211a are annular walls that are arranged at both ends of the spacer body 211 in the Z-axis direction and both ends of the spacer body 211 in the X-axis direction, protrude in the Y-axis direction from both ends of the spacer body 211 in the Z-axis direction and both ends of the spacer body 211 in the X-axis direction, and surround the spacer body 211. The spacer wall portions 211a are arranged on both sides of the container 110 of the energy storage element 100 in the Z-axis direction and both sides of the container 110 in the X-axis direction, and hold the energy storage element 100. The spacer wall portions 211a are open at positions facing the terminals 120, gas discharge valve 113, and liquid injection portion 114 of the energy storage element 100, and hold the energy storage element 100 with these exposed (see FIGS. 6 and 7 , etc.).

[0051] The spacer protrusions 212 are walls disposed at both ends of the spacer body 211 in the X-axis direction at the ends in the Z-axis positive direction, and protrude in the Z-axis positive direction. The spacer protrusions 212 are L-shaped portions when viewed from the Z-axis direction, and include a flat, rectangular wall parallel to the XZ plane and extending in the X-axis direction, and a flat, rectangular wall parallel to the YZ plane and extending in the Y-axis direction. The spacer protrusions 212 include spacer protrusions 212a on the walls parallel to the XZ plane. The spacer protrusions 212a protrude in a direction intersecting the arrangement direction (Z-axis direction) of the energy storage elements 100 and the bus bars 300. In this embodiment, the spacer protrusions 212a protrude in the Y-axis direction, which is the arrangement direction of the energy storage elements 100 and the spacers 200. In the spacer 210 shown in FIG. 4 , the spacer protrusion 212 a protrudes in the negative Y-axis direction, while in the spacer 210 provided in the energy storage unit 10 in the negative Y-axis direction, the spacer protrusion 212 a protrudes in the positive Y-axis direction. The spacer protrusion 212 a is a columnar (rectangular) convex portion with a rectangular portion extending in the Z-axis direction when viewed from the Z-axis direction, but the shape of the spacer protrusion 212 a is not limited to this. When viewed from the Z-axis direction, the spacer protrusion 212 a may be a circular, elliptical, oval, semicircular, semi-elliptical, semi-oval, or polygonal shape other than a rectangle. The spacer protrusion 212 has two spacer protrusions 212 a aligned in the X-axis direction.

[0052] The spacer protrusions 213 are disposed at both ends in the X-axis direction at the ends of the spacer body 211 in the positive Z-axis direction, and are flat, rectangular walls parallel to the YZ plane that protrude in the positive Z-axis direction. The spacer protrusions 213 are disposed outside the spacer protrusions 212 in the X-axis direction. In other words, the two spacer protrusions 212 are disposed between the two spacer protrusions 213. The spacer protrusions 213 protrude further in the positive Z-axis direction than the spacer protrusions 212. The spacer protrusions 212 and 213 are part of walls that surround the periphery of the bus bar 300 in the X-axis direction and the periphery in the Y-axis direction.

[0053] 3.2 Description of Spacer 220 The spacer 220 has the same shape in its half in the positive direction of the X-axis and its half in the negative direction of the X-axis, except for the configuration of the spacer protrusions 222 and 223. The spacer 220 includes a spacer body 221, a spacer wall 221 a, and spacer protrusions 222, 223, and 224.

[0054] The spacer main body 221 is a flat, rectangular portion that constitutes the main body of the spacer 220, and is disposed parallel to the XZ plane. The spacer main body 221 is a portion that faces the energy storage elements 100 in the Y-axis direction. Specifically, the spacer main body 221 is disposed between the containers 110 of the two energy storage units 10 in the Y-axis direction. The spacer main body 221 is disposed facing the long side surfaces of the containers 110 of the energy storage elements 100 in the Y-axis direction and in contact with the long side surfaces so as to cover the entire long side surfaces of the containers 110 of the energy storage elements 100.

[0055] The spacer wall portions 221a are annular walls that are arranged at both ends of the spacer body 221 in the Z-axis direction and both ends in the X-axis direction, protrude from both ends of the spacer body 221 in the Z-axis direction and both ends in the X-axis direction to both sides in the Y-axis direction, and surround the spacer body 221. The spacer wall portions 221a are arranged at both sides in the Z-axis direction and both sides in the X-axis direction of the container 110 of the energy storage element 100, and hold the energy storage element 100. The spacer wall portions 221a are open at positions facing the terminals 120, gas discharge valves 113, and liquid injection portions 114 of the energy storage element 100, and hold the energy storage element 100 with these exposed (see FIGS. 6 and 7, etc.).

[0056] The spacer protrusion 222 is a plate-like wall that is disposed at the end of the spacer body 221 in the negative X-axis direction at the end of the spacer body 221 in the positive Z-axis direction, protrudes in the positive Z-axis direction, and extends in the X-axis direction parallel to the XZ plane. The spacer protrusion 222 is a portion that is inserted into a recess in a curved portion 301 a of a bus bar 300 (described later) (see FIG. 7 ).

[0057] The spacer protrusion 223 is disposed at the end of the spacer body 221 in the positive X-axis direction at the end of the spacer body 221 in the positive Z-axis direction. The spacer protrusion 223 is a flat, rectangular wall extending in the X-axis direction parallel to the XZ plane and protruding in the positive Z-axis direction. The spacer protrusion 223 includes a spacer protrusion 223a. The spacer protrusion 223a protrudes in a direction intersecting the arrangement direction (Z-axis direction) of the energy storage elements 100 and the bus bar 300. In this embodiment, the spacer protrusion 223a protrudes on both sides in the Y-axis direction. The spacer protrusion 223a is a columnar (rectangular) convex portion having a rectangular portion extending in the Z-axis direction as viewed in the Z-axis direction, but the shape of the spacer protrusion 223a is not limited thereto. The spacer protrusion 223a may be a circular, elliptical, oval, semicircular, semi-oval, semi-elliptical, or polygonal shape other than a rectangle as viewed in the Z-axis direction. Two spacer protrusions 223a are provided on each side of the spacer protrusion 223 in the Y-axis direction, and are aligned in the X-axis direction.

[0058] The spacer protrusions 224 are disposed at both ends in the X-axis direction at the ends of the spacer body 221 in the positive Z-axis direction, and are flat, rectangular walls that protrude in the positive Z-axis direction and are parallel to the YZ plane. The spacer protrusions 224 are disposed outside the spacer protrusions 222 and 223 in the X-axis direction. In other words, the spacer protrusions 222 and 223 are disposed between the two spacer protrusions 224. The spacer protrusions 224 protrude in the positive Z-axis direction further than the spacer protrusions 222 and 223. The spacer protrusions 223 and 224 are part of the walls that surround the periphery of the bus bar 300 in the X-axis direction and the periphery in the Y-axis direction.

[0059] The spacer protrusion 224 includes a spacer opening 224a. The spacer opening 224a is a recess (notch) formed by recessing the end surface of the spacer protrusion 224 in the Y-axis direction and penetrating the end of the spacer protrusion 224 in the Y-axis direction in the X-axis direction. A spacer opening 224a is formed at each of both ends of the spacer protrusion 224 in the Y-axis direction. While the spacer opening 224a has a rectangular shape when viewed in the X-axis direction, the shape of the spacer opening 224a is not limited thereto. When viewed in the X-axis direction, the spacer opening 224a may be semicircular, semi-elliptical, semi-oval, or a polygonal shape other than a rectangle. The spacer opening 224a is formed in a portion of the spacer protrusion 224 that is more positive in the Z-axis direction than the spacer protrusions 222 and 223. Specifically, when the bus bar 300 is disposed in the energy storage unit 10, the spacer opening 224a is positioned more positive in the Z-axis direction than the bus bar 300 (see FIG. 6 ). The spacer opening 224a is formed at each of both ends of the spacer protrusion 224 in the Y-axis direction, but may be formed at one end.

[0060] 3.3 Description of Spacer 230 The spacer 230 has the same shape in its half in the positive direction of the X-axis and its half in the negative direction of the X-axis, except for the configuration of the spacer protrusions 232 and 233. The spacer 230 includes a spacer body 231, a spacer wall 231 a, and spacer protrusions 232, 233, and 234.

[0061] The spacer main body 231 is a flat, rectangular portion that constitutes the main body of the spacer 230, and is disposed parallel to the XZ plane. The spacer main body 231 is a portion that faces the energy storage elements 100 in the Y-axis direction. Specifically, the spacer main body 231 is disposed between the containers 110 of the two energy storage units 10 in the Y-axis direction. The spacer main body 231 is disposed facing the long side surfaces of the containers 110 of the energy storage elements 100 in the Y-axis direction and in contact with the long side surfaces so as to cover the entire long side surfaces of the containers 110 of the energy storage elements 100.

[0062] The spacer wall portions 231a are annular walls that are arranged at both ends of the spacer body 231 in the Z-axis direction and both ends in the X-axis direction, protrude from both ends of the spacer body 231 in the Z-axis direction and both ends in the X-axis direction to both sides in the Y-axis direction, and surround the spacer body 231. The spacer wall portions 231a are arranged at both sides in the Z-axis direction and both sides in the X-axis direction of the container 110 of the energy storage element 100, and hold the energy storage element 100. The spacer wall portions 231a are open at positions facing the terminals 120, gas discharge valve 113, and liquid injection portion 114 of the energy storage element 100, and hold the energy storage element 100 with these exposed (see FIGS. 6 and 7, etc.).

[0063] The spacer protrusion 232 is disposed at the end of the spacer body 231 in the positive Z-axis direction, at the end in the negative X-axis direction, and is a wall that protrudes in the positive Z-axis direction. The spacer protrusion 232 is a T-shaped portion when viewed from the Z-axis direction, and includes a flat, rectangular wall that is parallel to the XZ plane and extends in the X-axis direction, and a flat, rectangular wall that is parallel to the YZ plane and extends in the Y-axis direction. The spacer protrusion 232 includes a spacer protrusion 232a on the wall parallel to the XZ plane. The spacer protrusion 232a protrudes in a direction intersecting the arrangement direction (Z-axis direction) of the energy storage elements 100 and the bus bars 300. In this embodiment, the spacer protrusion 232a protrudes on both sides in the Y-axis direction. The spacer protrusion 232a is a columnar (rectangular) convex portion having a rectangular portion that extends in the Z-axis direction when viewed from the Z-axis direction, but the shape of the spacer protrusion 232a is not limited to this. When viewed from the Z-axis direction, the spacer protrusion 232a may be a portion having a circular shape, an elliptical shape, an oval shape, a semicircular shape, a semi-elliptical shape, a semi-oval shape, or a polygonal shape other than a rectangle, etc. Two spacer protrusions 232a aligned in the X-axis direction are provided on both sides in the Y-axis direction of a wall of the spacer protrusion 232 that is parallel to the XZ plane.

[0064] The spacer protrusion 233 is a plate-like wall that is disposed at the end of the spacer body 231 in the positive X-axis direction at the end of the spacer body 231 in the positive Z-axis direction, protrudes in the positive Z-axis direction, and extends in the X-axis direction parallel to the XZ plane. The spacer protrusion 233 is a portion that is inserted into a recess in a curved portion 301 a of a bus bar 300 (described later) (see FIG. 7 ).

[0065] The spacer protrusions 234 are disposed at both ends in the X-axis direction at the ends of the spacer body 231 in the positive Z-axis direction, and are flat, rectangular walls that protrude in the positive Z-axis direction and are parallel to the YZ plane. The spacer protrusions 234 are disposed outside the spacer protrusions 232 and 233 in the X-axis direction. In other words, the spacer protrusions 232 and 233 are disposed between the two spacer protrusions 234. The spacer protrusions 234 protrude in the positive Z-axis direction further than the spacer protrusions 232 and 233. The spacer protrusions 232 and 234 are part of the walls that surround the periphery of the bus bar 300 in the X-axis direction and the periphery in the Y-axis direction.

[0066] The spacer protrusion 234 includes a spacer opening 234a. The spacer opening 234a is a recess (notch) formed by recessing the end surface of the spacer protrusion 234 in the Y-axis direction and penetrating the end of the spacer protrusion 234 in the Y-axis direction in the X-axis direction. A spacer opening 234a is formed at each of both ends of the spacer protrusion 234 in the Y-axis direction. Although the spacer opening 234a has a rectangular shape when viewed in the X-axis direction, the shape of the spacer opening 234a is not limited thereto. When viewed in the X-axis direction, the spacer opening 234a may be semicircular, semi-elliptical, semi-oval, or a polygonal shape other than a rectangle. The spacer opening 234a is formed in a portion of the spacer protrusion 234 that is more positive in the Z-axis direction than the spacer protrusions 232 and 233. Specifically, when the bus bar 300 is disposed in the energy storage unit 10, the spacer opening 234a is positioned more positive in the Z-axis direction than the bus bar 300 (see FIG. 6 ).

[0067] [4 Description of bus bar 300] Next, the configuration of bus bar 300 (bus bar 310, bus bar 320, and bus bar 330) will be described in detail. Because bus bars 310, bus bar 320, and bus bar 330 included in energy storage unit 10 all have the same configuration, they will be illustrated as bus bar 300 below as a representative, and this configuration will be described in detail. Fig. 5 is a perspective view showing the configuration of bus bar 300 according to this embodiment. Fig. 5 illustrates an enlarged view of bus bar 300 shown in Fig. 2.

[0068] As shown in FIG. 5 , busbar 300 includes busbar main body 301, busbar opening 302, and busbar opening 303. Busbar main body 301 is a plate-like, rectangular portion that constitutes the main body of busbar 300 and is disposed parallel to the XY plane. Busbar main body 301 includes curved portion 301a at its center in the Y-axis direction. Curved portion 301a is a portion that curves to protrude in the positive direction of the Z-axis, with the surface of busbar main body 301 facing the positive Z-axis protruding and the surface of busbar main body 301 facing the negative Z-axis recessed. Spacer protrusion 222 of spacer 220 or spacer protrusion 233 of spacer 230 is inserted into the recess formed on the surface of curved portion 301a facing the negative Z-axis (see FIG. 7 ).

[0069] The busbar openings 302 are recesses (notches) formed by recessing the end face of the busbar body 301 in the positive Y-axis direction, penetrating the end of the busbar body 301 in the positive Y-axis direction in the Z-axis direction. Two busbar openings 302 are formed side by side in the X-axis direction at the end of the busbar body 301 in the positive Y-axis direction. Although the busbar openings 302 have a rectangular shape when viewed in the Z-axis direction, the shape of the busbar openings 302 is not limited thereto. When viewed in the Z-axis direction, the busbar openings 302 may have a semicircular shape, a semi-elliptical shape, a semi-oval shape, or a polygonal shape other than a rectangle. Hereinafter, the busbar openings 302 of the busbar 310 will also be referred to as busbar openings 312, the busbar openings 302 of the busbar 320 will also be referred to as busbar openings 322, and the busbar openings 302 of the busbar 330 will also be referred to as busbar openings 332.

[0070] The busbar openings 303 are recesses (notches) formed by recessing the end face of the busbar body 301 in the negative Y-axis direction, penetrating the end of the busbar body 301 in the negative Y-axis direction in the Z-axis direction. Two busbar openings 303 are formed side by side in the X-axis direction at the end of the busbar body 301 in the negative Y-axis direction. Although the busbar openings 303 have a rectangular shape when viewed in the Z-axis direction, the shape of the busbar openings 303 is not limited thereto. When viewed in the Z-axis direction, the busbar openings 303 may be semicircular, semi-elliptical, semi-oval, or polygonal shapes other than rectangular. Hereinafter, the busbar openings 303 of the busbar 310 will also be referred to as busbar openings 313, the busbar openings 303 of the busbar 320 will also be referred to as busbar openings 323, and the busbar openings 303 of the busbar 330 will also be referred to as busbar openings 333.

[0071] [5. Description of Relationship Between Spacer 200, Bus Bar 300, and Bus Bar Cover 400] Next, the relationship between spacer 200, bus bar 300, and bus bar cover 400 will be described in detail. In particular, the configuration in which spacer 200 positions bus bar 300 and the configuration in which spacer 200 holds bus bar cover 400 will be described in detail. FIG. 6 is a perspective view showing the configuration in which spacer 200 positions bus bar 300 and holds bus bar cover 400 according to this embodiment. FIG. 6 shows the configuration in a state in which bus bar cover 400 is removed from spacer 200 in the energy storage unit 10 shown in FIG. 1. FIG. 7 is a plan view showing the configuration in which spacer 200 positions bus bar 300 according to this embodiment. FIG. 7 shows the configuration in which bus bar cover 400 is removed from energy storage unit 10 shown in FIG. 6, viewed from the positive direction of the Z axis.

[0072] As described above, the spacer protrusion 212 of the spacer 210 in the positive direction of the Y axis has the spacer protrusion 212a. Similarly, the spacer protrusion 212 of the spacer 210 in the negative direction of the Y axis has the spacer protrusion 212a. The spacer protrusion 223 of the spacer 220 in the positive direction of the Y axis has the spacer protrusion 223a. Similarly, the spacer protrusion 223 of the spacer 220 in the negative direction of the Y axis has the spacer protrusion 223a. The spacer protrusion 232 of the spacer 230 has the spacer protrusion 232a. The bus bar 300 has a bus bar opening 302 and a bus bar opening 303. That is, to explain the bus bars 310, 320, and 330, the bus bar 310 has a bus bar opening 312 and a bus bar opening 313. The bus bar 320 has a bus bar opening 322 and a bus bar opening 323. The bus bar 330 includes a bus bar opening 332 and a bus bar opening 333 .

[0073] 6 and 7 , spacer protrusions 212a of spacer 210 extending in the positive direction of the Y axis are inserted into busbar openings 312 of busbar 310. Spacer protrusions 232a of spacer 230 extending in the positive direction of the Y axis are inserted into busbar openings 313 of busbar 310. That is, two spacer protrusions 212a are inserted into two busbar openings 312, and two spacer protrusions 232a are inserted into two busbar openings 313. In this embodiment, spacer protrusions 212a are arranged with a gap between them and do not contact busbar openings 312, but may also come into contact with busbar openings 312. Spacer protrusions 232a are arranged with a gap between them and do not contact busbar openings 313, but may also come into contact with busbar openings 313.

[0074] Similarly, spacer protrusions 232a of spacer 230 protruding in the negative Y-axis direction are inserted into busbar openings 322 of busbar 320. Spacer protrusions 212a of spacer 210 extending in the negative Y-axis direction are inserted into busbar openings 323 of busbar 320. That is, two spacer protrusions 232a are inserted into two busbar openings 322, and two spacer protrusions 212a are inserted into two busbar openings 323. In this embodiment, spacer protrusions 232a are arranged with a gap between them and do not contact busbar openings 322, but they may also come into contact with busbar openings 322. Spacer protrusions 212a are arranged with a gap between them and do not contact busbar openings 323, but they may also come into contact with busbar openings 323.

[0075] Similarly, the spacer protrusions 223a that protrude in the negative Y-axis direction and that are provided on the spacer 220 that is oriented in the positive Y-axis direction are inserted into the busbar openings 332 of the busbar 330. The spacer protrusions 223a that protrude in the positive Y-axis direction and that are provided on the spacer 220 that is oriented in the negative Y-axis direction are inserted into the busbar openings 333 of the busbar 330. That is, two spacer protrusions 223a are inserted into two busbar openings 332, and two spacer protrusions 223a are inserted into two busbar openings 333. In this embodiment, the spacer protrusions 223a are arranged with a gap between them and do not contact the busbar openings 332, but they may also come into contact with the busbar openings 332. The spacer protrusions 223a are arranged with a gap between them and do not contact the busbar openings 333, but they may also come into contact with the busbar openings 333.

[0076] As described above, one of spacer 200 and busbar 300 (spacer 200 in this embodiment) has protrusions (spacer protrusions 212a, 223a, 232a in this embodiment), and the other of spacer 200 and busbar 300 (busbar 300 in this embodiment) has openings into which the protrusions are inserted (busbar openings 312, 313, 322, 323, 332, 333 in this embodiment).

[0077] The spacer 200 includes a spacer 210 and a spacer 230 in the positive direction of the Y axis as a first spacer and a second spacer sandwiching the energy storage device 100. One of the spacer 210 (first spacer) and the bus bar 310 (spacer 210 in this embodiment) includes a spacer protrusion 212a as a first protrusion. The other of the spacer 210 (first spacer) and the bus bar 310 (bus bar 310 in this embodiment) includes a bus bar opening 312 as a first opening into which the spacer protrusion 212a (first protrusion) is inserted. The spacer 230 (second spacer) and one of the bus bars 310 (spacer 230 in this embodiment) include a spacer protrusion 232a as a second protrusion. The other of the spacer 230 (second spacer) and the bus bar 310 (bus bar 310 in this embodiment) includes a bus bar opening 313 as a second opening into which the spacer protrusion 232a (second protrusion) is inserted. The same applies when the spacer 230 and the spacer 210 in the negative Y-axis direction are defined as the first spacer and the second spacer, and the same applies when the spacer 220 in the positive Y-axis direction and the spacer 220 in the negative Y-axis direction are defined as the first spacer and the second spacer.

[0078] As described above, the spacer protrusion 224 of the spacer 220 in the positive direction of the Y axis has the spacer opening 224 a. Similarly, the spacer protrusion 224 of the spacer 220 in the negative direction of the Y axis has the spacer opening 224 a. The spacer protrusion 234 of the spacer 230 has the spacer opening 234 a. The bus bar cover 400 has the cover protrusion 420.

[0079] In this configuration, as shown in FIG. 6 , the spacer opening 224 a of the spacer 220 and the spacer opening 234 a of the spacer 230 are disposed at the same position (same height) in the Z-axis direction. Therefore, the spacer opening 224 a and the spacer opening 234 a are connected to form a single opening. The cover protrusion 420 of the bus bar cover 400 is inserted into the opening formed by the spacer opening 224 a and the spacer opening 234 a. In this embodiment, the spacer openings 224 a on both sides in the X-axis direction of the two spacers 220 are connected to the spacer openings 234 a on both sides in the X-axis direction of the spacer 230, forming four openings. The four cover protrusions 420 of the bus bar cover 400 are inserted into these four openings. In this manner, the bus bar cover 400 is attached to the spacer 200, resulting in the state shown in FIG. 1 .

[0080] In this manner, the spacer 200 holds the bus bar cover 400. The spacer 200 includes a spacer 220 and a spacer 230 in the positive direction of the Y axis as third and fourth spacers that sandwich the energy storage device 100. The spacer 220 as the third spacer and the spacer 230 as the fourth spacer hold the bus bar cover 400. The same applies when the spacer 220 and the spacer 230 in the negative direction of the Y axis are defined as the third and fourth spacers. The same applies when the spacer 220 in the positive direction of the Y axis and the spacer 220 in the negative direction of the Y axis are defined as the third and fourth spacers. In other words, the spacer 220 in the positive direction of the Y axis and the spacer 220 in the negative direction of the Y axis also hold the bus bar cover 400. In this manner, the bus bar cover 400 is held by at least two spacers (the third spacer and the fourth spacer). The third spacer or the fourth spacer may be a spacer different from the first spacer or the second spacer described above, or may be the same spacer.

[0081] [6. Description of Effects] As described above, in the energy storage device 1 according to this embodiment, one of the spacer 200 and the bus bar 300 (the spacer 200) has protrusions (spacer protrusions 212a, 232a, etc.), and the other of the spacer 200 and the bus bar 300 (the bus bar 300) has openings (bus bar openings 312, 313, etc.). Therefore, by inserting the protrusions into the openings, the spacer 200 can position the bus bar 300. This allows the spacer 200 to be used to position the bus bar 300 in the energy storage device 1, simplifying the configuration of the energy storage device 1. Since the bus bar 300 can be positioned even without providing other components such as a bus bar holder, the number of parts can be reduced. Positioning the bus bar 300 using the spacer 200 that holds the energy storage elements 100 can improve the positioning accuracy of the bus bar 300 relative to the energy storage elements 100.

[0082] The protrusions (spacer protrusions 212a, 232a, etc.) protrude in a direction intersecting the arrangement direction of the energy storage elements 100 and the bus bar 300. As a result, the protrusions are inserted into openings (bus bar openings 312, 313, etc.) in the intersecting direction, allowing the spacer 200 to position the bus bar 300.

[0083] One of the first spacer (e.g., spacer 210) and busbar 300 has a first protrusion (e.g., spacer protrusion 212a), and the other of the first spacer (e.g., spacer 210) and busbar 300 has a first opening (e.g., busbar opening 312). One of the second spacer (e.g., spacer 230) and busbar 300 has a second protrusion (e.g., spacer protrusion 232a), and the other of the second spacer (e.g., spacer 230) and busbar 300 has a second opening (e.g., busbar opening 313). As a result, by inserting the first protrusion into the first opening and the second protrusion into the second opening, the busbar 300 can be positioned by the first spacer and the second spacer. Therefore, in the energy storage device 1, the busbar 300 can be positioned using two spacers (the first spacer and the second spacer), and therefore the busbar 300 can be stably positioned with a simple configuration.

[0084] The spacer 200 holds the bus bar cover 400. This allows the spacer 200 to be used to hold the bus bar cover 400 in the energy storage device 1, further simplifying the configuration of the energy storage device 1. Even if a separate member for holding the bus bar cover 400 is not provided, the bus bar cover 400 can be held, thereby reducing the number of parts. By holding the bus bar cover 400 with the spacer 200 that positions the bus bar 300, the positioning accuracy of the bus bar cover 400 relative to the bus bar 300 can be improved.

[0085] The third spacer (spacer 220, etc.) and the fourth spacer (spacer 230, etc.) hold the bus bar cover 400, so that two spacers (the third spacer and the fourth spacer) can be used to hold the bus bar cover 400. This allows the bus bar cover 400 to be stably held with a simple configuration.

[0086] By configuring the bus bar cover 400 to be held by the two spacers 220 and 230 (third spacer and fourth spacer), the two spacers 220 and 230 can be formed with notched spacer openings 224a and 234a, which makes it easy to make the shape of the spacer 200 using a mold. This makes it easy to form the shape of the spacer 200 to hold the bus bar cover 400. When the two spacers 220 are the third spacer and the fourth spacer, it is only necessary to prepare two identical spacers 220 with the spacer openings 224a formed therein as the third spacer and the fourth spacer, and therefore it is only necessary to manufacture one type of spacer 220.

[0087] The effects described above regarding the positioning of bus bar 310 can also be applied to the positioning of bus bar 320 and bus bar 330 in the same manner.

[0088] [7 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.

[0089] (Variation 1) In the above embodiment, spacer 200 has a protrusion, and bus bar 300 has an opening into which the protrusion is inserted. However, bus bar 300 may have a protrusion, and spacer 200 may have an opening into which the protrusion is inserted. Figure 8 is a plan view showing a configuration in which spacers 210A and 230A position bus bar 310A according to Variation 1 of this embodiment. Figure 8 corresponds to the bus bar 310 and its surrounding configuration in Figure 7.

[0090] 8 , the spacer protrusion 212 of the spacer 210A in this modification has two spacer openings 212b instead of the two spacer protrusions 212a provided on the spacer protrusion 212 of the spacer 210 in the above embodiment. The spacer protrusion 232 of the spacer 230A in this modification has two spacer openings 232b instead of the two spacer protrusions 232a provided on the spacer protrusion 232 of the spacer 230 in the above embodiment. The bus bar 310A in this modification has two bus bar protrusions 314 and two bus bar protrusions 315 instead of the two bus bar openings 312 and two bus bar openings 313 provided on the bus bar 310 in the above embodiment.

[0091] The spacer opening 212b is a recess formed on the surface of the spacer protrusion 212 facing the negative Y-axis direction. The spacer opening 232b is a recess formed on the surface of the spacer protrusion 232 facing the positive Y-axis direction. The busbar protrusion 314 is a protrusion that protrudes from the busbar main body 301 in the positive Y-axis direction. The busbar protrusion 315 is a protrusion that protrudes from the busbar main body 301 in the negative Y-axis direction. The shapes of the spacer openings 212b, 232b and the busbar protrusions 314, 315 are not particularly limited. Two busbar protrusions 314 are inserted into the two spacer openings 212b, and two busbar protrusions 315 are inserted into the two spacer openings 232b. In this modification, the busbar protrusions 314 are arranged with a gap between them and do not contact the spacer openings 212b, but may also contact the spacer openings 212b. The bus bar projections 315 are arranged with a gap therebetween and do not contact the spacer openings 232b, but may contact the spacer openings 232b.

[0092] As described above, one of the spacer 200 and the bus bar 300 (bus bar 310A in this modification) has protrusions (bus bar protrusions 314 and 315 in this modification). The other of the spacer 200 and the bus bar 300 (spacers 210A and 230A in this modification) has openings into which the protrusions are inserted (spacer openings 212b and 232b in this modification). The spacer 210A and the spacer 230A are examples of a first spacer and a second spacer. The bus bar protrusions 314 and 315 are examples of a first protrusion and a second protrusion. The spacer openings 212b and 232b are examples of a first opening and a second opening. The other configuration of this modification is the same as that of the above-described embodiment, and therefore a description thereof will be omitted. This modification can also achieve the same effects as those of the above-described embodiment.

[0093] In this modification, spacer 210A may have a configuration in which only one of two spacer protrusions 212a provided on spacer 210 in the above embodiment is changed to one spacer opening 212b. In this case, bus bar 310A has a configuration in which only one of two bus bar openings 312 provided on bus bar 310 in the above embodiment is changed to one bus bar protrusion 314. The same applies to spacer 230A.

[0094] (Modification 2) In the above embodiment, the protrusions of spacer 200 protrude in the Y-axis direction and are inserted into the openings of bus bar 300, but they may protrude in a direction other than the Y-axis direction. Fig. 9 is a plan view showing a configuration in which spacers 210B and 230B according to Modification 2 of this embodiment position bus bar 310B. Fig. 9 corresponds to the bus bar 310 and its surrounding configuration in Fig. 7.

[0095] 9 , a spacer 210B in this modification includes spacer protrusions 212c and 213a instead of the two spacer protrusions 212a included in the spacer 210 in the above embodiment. A spacer 230B in this modification includes spacer protrusions 232c and 234b instead of the two spacer protrusions 232a included in the spacer 230 in the above embodiment. A busbar 310B in this modification includes two busbar openings 316 and two busbar openings 317 instead of the two busbar openings 312 and two busbar openings 313 included in the busbar 310 in the above embodiment.

[0096] Spacer protrusion 212c is a protrusion (convex portion) that protrudes in the negative X-axis direction from a wall of spacer protrusion 212 that is parallel to the YZ plane. Spacer protrusion 213a is a protrusion (convex portion) that protrudes in the positive X-axis direction from spacer protrusion 213. Spacer protrusion 232c is a protrusion (convex portion) that protrudes in the negative X-axis direction from a wall of spacer protrusion 232 that is parallel to the YZ plane. Spacer protrusion 234b is a protrusion (convex portion) that protrudes in the positive X-axis direction from spacer protrusion 234. The two busbar openings 316 are recesses formed by recessing both surfaces in the X-axis direction at the end of busbar body 301 that is located in the positive Y-axis direction. The two busbar openings 317 are recesses formed by recessing both surfaces in the X-axis direction at the end of busbar body 301 that is located in the negative Y-axis direction. The shapes of the spacer protrusions 212c, 213a, 232c, and 234b and the busbar openings 316 and 317 are not particularly limited. The spacer protrusions 212c and 213a are inserted into the two busbar openings 316, and the spacer protrusions 232c and 234b are inserted into the two busbar openings 317. In this modification, the spacer protrusions 212c and 213a are arranged with a gap therebetween and not in contact with the busbar opening 316, but they may also be in contact with the busbar opening 316. The spacer protrusions 232c and 234b are arranged with a gap therebetween and not in contact with the busbar opening 317, but they may also be in contact with the busbar opening 317.

[0097] In this manner, spacer protrusions 212c, 213a, 232c, and 234b protrude in the X-axis direction, which is a direction intersecting the arrangement direction (Z-axis direction) of energy storage devices 100 and bus bar 300. One of spacer 200 and bus bar 300 (spacers 210B and 230B in this modification) has protrusions (spacer protrusions 212c, 213a, 232c, and 234b in this modification). The other of spacer 200 and bus bar 300 (bus bar 310B in this modification) has openings into which the protrusions are inserted (bus bar openings 316 and 317 in this modification). Spacer 210B and spacer 230B are examples of a first spacer and a second spacer. The other configuration of this modification is the same as that of the above-described embodiment, and therefore description thereof will be omitted. This modification can also achieve the same effects as those of the above-described embodiment.

[0098] In this modification, the positions and number of spacer protrusions formed on spacers 210B and 230B are not particularly limited. In this modification, spacer 220 may also have spacer protrusions. In this modification, similar to the above modification 1, bus bar 310B may have protrusions that protrude in the X-axis direction, and the protrusions may be inserted into openings in spacers 210B and 230B.

[0099] (Other Modifications) In the above embodiment, the spacer protrusions of spacer 200 may be inserted into the bus bar openings of bus bar 300 by snap fitting, or may be inserted into the bus bar openings in any other manner. The arrangement positions and numbers of the spacer protrusions and bus bar openings are not particularly limited.

[0100] In the above embodiment and variant example 2, the spacer protrusions of the spacer 200 protrude in the Y-axis direction or the X-axis direction, but they may protrude in a direction inclined from the Y-axis direction or the X-axis direction, or may protrude in the Z-axis direction. In other words, the spacer protrusions are not limited to protruding in a direction intersecting the arrangement direction of the energy storage elements 100 and the bus bars 300.

[0101] In the above embodiment, the busbar opening of the busbar 300 is a notch (recess) formed in the busbar 300, but it may have any shape, such as a through-hole formed in the busbar 300, as long as the spacer protrusion of the spacer 220 can be inserted therein.

[0102] In the above embodiment, the spacer protrusions of two spacers (first spacer and second spacer) are inserted into the bus bar opening of bus bar 300, but it is also possible that only the spacer protrusion of one spacer is inserted.

[0103] In the above embodiment, the cover protrusions 420 of the bus bar cover 400 may be inserted into the spacer openings of the spacer 200 by snap fitting, or may be inserted into the spacer openings in any other form. The cover protrusions 420 may have any shape. When viewed in the Z-axis direction, the cover protrusions 420 may have a semicircular, semi-elliptical, semi-oval, or polygonal shape other than a rectangle. When viewed in the X-axis direction, the cover protrusions 420 may have a circular, elliptical, oval, or polygonal shape other than a rectangle. The corners of the cover protrusions 420 may be chamfered. The spacer openings of the spacer 200 may be through-holes instead of notches, or may be recesses recessed in the X-axis direction instead of penetrating in the X-axis direction. The bus bar cover 400 may be held to the spacer 200 by being fixed to the spacer 200 by bolting, screwing, adhesive, cohesive, welding, or the like.

[0104] In the above embodiment, the cover protrusions 420 of the bus bar cover 400 are inserted into the spacer openings 224a of the spacer 220 and the spacer openings 234a of the spacer 230, but this is not limited to this. The cover protrusions 420 may be inserted into only one of the spacer openings 224a and the spacer openings 234a. The cover protrusions 420 may be inserted into the spacer openings 224a of two spacers 220, but not into the spacer openings 234a of the spacer 230. In this case, the spacer 230 may not have a spacer opening 234a, and the spacer 230 itself may not be disposed. Since two identical spacers 220 each having a spacer opening 224a formed therein are prepared, only one type of spacer 220 needs to be manufactured, which facilitates the manufacture of the energy storage device 1. Similarly, the spacer 220 may not have a spacer opening 224a, and the spacer 220 itself may not be disposed.

[0105] In the above embodiment, the spacers 220 and 230 hold the bus bar cover 400 , but the spacer 210 may hold the bus bar cover 400 .

[0106] In the above embodiment, the bus bar cover 400 is held by at least two spacers (the third spacer and the fourth spacer), but it may be held by only one spacer.

[0107] In the above embodiment, the bus bar cover 400 covers the top of all of the energy storage elements 100 included in the energy storage unit 10, but it may be configured to cover only a portion of them.

[0108] In the above embodiment, the spacer 200 holds the bus bar cover 400, but the spacer 200 may not hold the bus bar cover 400. In this case, the energy storage device 1 does not need to include the bus bar cover 400.

[0109] In the above embodiment, one of the spacer 200 and the bus bar 300 has a protrusion, and the other of the spacer 200 and the bus bar 300 has an opening into which the protrusion is inserted, but both the spacer 200 and the bus bar 300 do not necessarily have a protrusion or an opening.

[0110] In the above embodiment, two spacers 210, two spacers 220, and one spacer 230 are arranged alternately in the Y-axis direction with the energy storage element 100, but it is also possible for any of the spacers to not be arranged.

[0111] Any combination of the components of the above-described embodiment and its modifications is also included within the scope of the present invention.

[0112] The present invention can be applied to an electricity storage device including an electricity storage element such as a lithium ion secondary battery.

[0113] REFERENCE SIGNS LIST 1 Energy storage device 10 Energy storage unit 100 Energy storage element 110 Container 113 Gas discharge valve 114 Liquid injection part 120 Terminal 200, 210, 210A, 210B, 220, 230, 230A, 230B Spacer 211, 221, 231 Spacer body 211a, 221a, 231a Spacer wall part 212, 213, 222, 223, 224, 232, 233, 234 Spacer protrusion part 212a, 212c, 213a, 223a, 232a, 232c, 234b Spacer protrusion 212b, 224a, 232b, 234a Spacer opening part 300, 310, 310A, 310B, 320, 330 Bus bar 301 busbar body 301a curved portion 302, 303, 312, 313, 316, 317, 322, 323, 332, 333 busbar opening 314, 315 busbar projection 400 busbar cover 410 cover body 420 cover projection 500 exterior body

Claims

1. An energy storage device comprising: an energy storage element; a spacer; and a bus bar arranged alongside the energy storage element in a direction intersecting the arrangement direction of the energy storage element and the spacer, wherein one of the spacer and the bus bar has a protrusion, and the other of the spacer and the bus bar has an opening into which the protrusion is inserted.

2. The energy storage device according to claim 1, wherein the protrusions protrude in a direction intersecting the direction in which the energy storage elements and the bus bars are arranged.

3. The energy storage device according to claim 1 or 2, wherein the spacer comprises a first spacer and a second spacer that sandwich the energy storage element, one of the first spacer and the bus bar having a first protrusion, the other of the first spacer and the bus bar having a first opening into which the first protrusion is inserted, one of the second spacer and the bus bar having a second protrusion, and the other of the second spacer and the bus bar having a second opening into which the second protrusion is inserted.

4. The energy storage device according to claim 1 or 2, further comprising a bus bar cover that covers the bus bar, wherein the spacer holds the bus bar cover.

5. The energy storage device according to claim 4, wherein the spacer includes a third spacer and a fourth spacer that sandwich the energy storage element, and the third spacer and the fourth spacer hold the bus bar cover.

6. An energy storage device comprising: an energy storage element; a spacer; a bus bar arranged alongside the energy storage element in a direction intersecting an arrangement direction of the energy storage element and the spacer; and a bus bar cover covering the bus bar, wherein the spacer holds the bus bar cover.

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