Power storage device

Abstract

To provide a power storage device capable of suppressing positional deviation of a shim.SOLUTION: The energy storage apparatus includes the energy storage unit 10 including the energy storage devices 100, and the shim 300 disposed adjacently to the energy storage unit 10, the shim 300 includes the projecting portion 312 projecting toward the energy storage unit 10, and the energy storage unit 10 includes the recessed portion 237 into which the projecting portion 312 is inserted. By inserting the projecting portion 312 of the shim 300 into the recessed portion 237 of the energy storage unit 10, the shim 300 can be positioned with respect to the energy storage unit 10 and hence, the positional displacement of the shim 300 can be suppressed.SELECTED DRAWING: Figure 7A

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a battery module in which a shim is placed between a battery stack and a housing case, and the shim is used to pressurize the battery stack with a predetermined pressure, thereby making it possible to suppress variations in the pressure even if manufacturing errors occur in the battery stack and the housing case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-44183 Summary of the Invention [Problem to be solved by the invention]

[0004] In the battery module disclosed in Patent Document 1, if the shim is misaligned when it is placed between the battery stack and the housing case, problems such as the battery stack not being able to be compressed with an appropriate pressure may occur. If the bottom of the housing case has a rounded portion (rounded corner), and the shim is placed in a tilted state in contact with the rounded portion, the shim may cause wear on the housing case or a deterioration in vibration resistance.

[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 suppress misalignment of a shim. [Means for solving the problem]

[0006] An energy storage device according to one aspect of the present invention comprises an energy storage unit having an energy storage element, and a shim arranged adjacent to the energy storage unit, the shim having a convex portion protruding toward the energy storage unit, and the energy storage unit having a concave portion into which the convex portion is inserted. [Effects of the Invention]

[0007] According to the electricity storage device of the present invention, it is possible to suppress misalignment of the shim. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing the configuration of an electricity storage device according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view showing the energy storage elements, spacers, and shims of the energy storage unit included in the energy storage device according to the embodiment. [Figure 3] FIG. 3 is a perspective view showing the configuration of the energy storage element according to the embodiment. [Figure 4] FIG. 4 is a perspective view showing the configuration of a spacer according to the embodiment. [Figure 5] FIG. 5 is a perspective view showing the configuration of a shim according to the embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing the configuration of a shim and a spacer according to the embodiment. [Figure 7A] FIG. 7A is a cross-sectional view showing the positional relationship between a shim, an electricity storage unit (spacer), and a case (case main body) according to the embodiment. [Figure 7B] FIG. 7B is a cross-sectional view showing the configuration around the end of the shim according to the embodiment. [Figure 8] FIG. 8 is a perspective view showing a configuration of a shim according to the first modification of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] (1) An energy storage device according to one aspect of the present invention comprises an energy storage unit having an energy storage element, and a shim arranged adjacent to the energy storage unit, the shim having a convex portion protruding toward the energy storage unit, and the energy storage unit having a concave portion into which the convex portion is inserted.

[0010] In an energy storage device according to one aspect of the present invention, the shim includes a protrusion that protrudes toward the energy storage unit, and the energy storage unit includes a recess into which the protrusion is inserted. As a result, the shim can be positioned relative to the energy storage unit by inserting the protrusion of the shim into the recess of the energy storage unit, thereby suppressing positional deviation of the shim.

[0011] (2) In the energy storage device described in (1) above, the energy storage unit may further include an insulating spacer disposed between the shim and the energy storage element, and the recess may be formed in the spacer.

[0012] According to the energy storage device described in (2) above, recesses can be easily formed in the energy storage unit by forming recesses in the insulating spacer disposed between the shim and the energy storage element. The insulating spacer can insulate between the energy storage element and the shim, and by inserting the protrusions of the shim into the recesses of the spacer, the recesses of the spacer can actively insulate the protrusions of the shim.

[0013] (3) In the energy storage device described in (1) or (2) above, the shim may have a through hole penetrating in a first direction, which is the arrangement direction of the energy storage unit and the shim, and the convex portion may protrude from an end of the through hole toward the energy storage unit.

[0014] According to the energy storage device described in (3) above, the protrusions of the shim protrude from the ends of the through holes of the shim toward the energy storage unit, which makes it possible to check the positions of the recesses of the energy storage unit from the through holes of the shim and to check whether the protrusions of the shim are inserted into the recesses of the energy storage unit.

[0015] (4) In the energy storage device described in (3) above, the convex portion may protrude from the end of the through hole in a second direction that intersects with the first direction, and the area of ​​the surface of the convex portion facing the second direction may be less than or equal to the opening area of ​​the through hole.

[0016] According to the energy storage device described in (4) above, the convex portion of the shim protrudes from the end of the through hole in the second direction, and the area of ​​the surface of the convex portion facing the second direction is equal to or less than the opening area of ​​the through hole in the shim. Because the area of ​​the surface of the convex portion of the shim is equal to or less than the opening area of ​​the through hole, the convex portion can be easily formed in the shim by cutting and raising the shim. By forming the convex portion in the shim by cutting and raising, material usage can be reduced compared to forming the convex portion by protruding the end of the shim and bending the protruding portion.

[0017] (5) In the energy storage device according to any one of (1) to (4) above, the energy storage unit may include a protrusion that protrudes toward the shim, and the recess may be formed in the protrusion.

[0018] According to the energy storage device described in (5) above, the recess of the energy storage unit is formed in a protruding portion of the energy storage unit that protrudes toward the shim. By forming the recess in the protruding portion of the energy storage unit in this way, the protruding portion can be used to form the recess.

[0019] (6) In the electricity storage device according to any one of (1) to (5) above, the protrusion may be disposed in a central portion of the shim.

[0020] According to the electricity storage device described in (6) above, the convex portion of the shim is disposed in the center of the shim, so that the shim can be stably positioned relative to the electricity storage unit.

[0021] (7) The energy storage device according to any one of (1) to (6) above may further include a case that houses the energy storage unit and the shim, and the shim may be positioned away from the bottom of the case.

[0022] According to the storage device described in (7) above, the shim is positioned away from the bottom of the case, so that even if a curved portion is formed on the bottom of the case, the shim can be prevented from coming into contact with the curved portion.

[0023] Hereinafter, with reference to the drawings, a description will be given of an energy storage device according to an embodiment of the present invention (including its modified examples). The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, manufacturing processes, and the order of manufacturing processes shown in the following embodiments are examples only 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.

[0024] In the following description and drawings, the X-axis direction is defined as the short-side direction of the energy storage device, the opposing direction of a pair of long sides of the case for the energy storage device, the arranging direction of a pair of terminals of the energy storage element, or the opposing direction of a pair of short sides of the container for the energy storage element. The Y-axis direction is defined as the long-side direction of the energy storage device, the opposing direction of the pair of short sides of the case for the energy storage device, the arranging direction of the energy storage unit and the shim, the arranging direction of multiple energy storage elements or multiple spacers, the arranging direction of the energy storage element and spacers, the thickness direction of the shim, the thickness direction (flattening direction) of the energy storage element or spacer, or the opposing direction of the pair of long sides of the container for the energy storage element. The Z-axis direction is defined as the arranging direction of the case body and the lid of the case for the energy storage device, the arranging direction of the opening of the case body and the bottom, the arranging direction of the energy storage unit and the shim and the bottom of the case, the protruding direction of the terminals of the energy storage element, the arranging direction of the container body and the container lid for the energy storage element, or the up-and-down direction. The X-axis, Y-axis, and Z-axis directions intersect with each other (orthogonal in this embodiment). Depending on the mode of use, the Z-axis direction may not be the up-down direction, but for the sake of convenience, the following description will be given assuming that the Z-axis direction is the up-down direction.

[0025] In the following description, the positive X-axis direction refers to the direction of the X-axis arrow, and the negative X-axis direction refers to the direction opposite to the positive X-axis direction. The X-axis direction simply refers to both or either of the positive and negative X-axis directions. The terms one side and the other side of the X-axis direction refer to one and the other of the positive and negative X-axis directions. Unless otherwise specified, the center and end portions of a component in the X-axis direction refer to the central and end portions when the component is divided into thirds along the X-axis. 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 Z-axis direction as the second direction, and the X-axis direction as the third direction. Expressions indicating relative directions or orientations, such as "parallel" and "orthogonal," may also refer to cases where the directions are not strictly those directions or orientations. Two directions being parallel (or orthogonal) not only means that the two directions are completely parallel (or orthogonal) but also means that the two directions are substantially parallel (or orthogonal), i.e., there is a difference of, for example, a few percent. In the following explanation, the term "insulation" means "electrical insulation." The volume resistivity of an insulating material is 1×10 6 Ωm or more is preferable, and 1×10 7 Ωm or more is preferable, and 1×10 10 More preferably, it is Ωm or more.

[0026] (Embodiment) [1. Description of the 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 the energy storage device 1 in a state where a lid 420 is removed from a case body 410 of a case 400. As a result, FIG. 1 illustrates a portion of the energy storage unit 10 and the shim 300 disposed inside the case 400. 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 the present embodiment, as well as the shim 300. FIG. 2 disassembles the components provided in the energy storage unit 10, illustrating 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, as well as the shim 300.

[0027] The power storage device 1 is a device that can charge with 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 moving 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 rolling stock 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 rolling stock 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, etc.

[0028] 1, the energy storage device 1 includes an energy storage unit 10, a shim 300, and a case 400 that houses the energy storage unit 10 and the shim 300. The energy storage device 1 also includes external terminals (a positive external terminal and a negative 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.

[0029] 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 rectangular parallelepiped here refers to a hexahedron with all faces formed of rectangles or squares. The same applies below. 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-constraint type module that does not include any constraint members (end plates, side plates, etc.) that constrain the plurality of energy storage elements 100 and spacers 200 in the Y-axis direction.

[0030] 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, 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 elements, 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 pillar 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.

[0031] The spacer 200 is a member that is flat in the Y-axis direction and is arranged alongside the energy storage element 100 in the Y-axis direction, insulating and / or thermally insulating the energy storage element 100 from other components. The spacer 200 is an insulating or thermally insulating plate that is arranged in the positive or negative Y-axis direction of the energy storage element 100, and that insulates and / or thermally insulating the energy storage elements 100 from each other, or from the energy storage element 100 to the shim 300 or the case 400. 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 functioning as a holder that positions the energy storage element 100. The spacer 200 has flow paths through which a refrigerant (a fluid such as air) flows, and thus also functions to cool the energy storage element 100.

[0032] 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 heat-insulating material such as mica.

[0033] Hereinafter, the spacers 200 arranged between 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 200a are arranged opposite the two energy storage elements 100. 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 shim 300 or the case 400) will also be referred to as spacers 200b. The spacers 200b in the negative Y-axis direction are arranged opposite the energy storage elements 100 at the ends in the negative Y-axis direction and the shim 300. The spacers 200b in the positive Y-axis direction are arranged opposite the energy storage elements 100 at the ends in the positive Y-axis direction and the side wall of the case 400. The spacers 200 (spacers 200a, 200b) are arranged alternately with the energy storage elements 100. FIG. 2 shows a configuration in which two energy storage elements 100, two spacers 200a, and one spacer 200b are alternately arranged, but the other spacers 200a and 200b are also alternately arranged with the energy storage elements 100 in a similar manner.

[0034] 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, and 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 have a single-sided support structure. All of 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.

[0035] In this embodiment, all of the spacers 200 (spacers 200a, 200b) are connected or fixed to each other so that adjacent spacers 200 are connected or fixed to each other. The energy storage unit 10 is compressed by a constant pressure load by the shim 300 inside the case 400 (case body 410). As a result, the entire energy storage unit 10 is fixed to the case 400 (case body 410).

[0036] The shim 300 is a plate-like, substantially rectangular member disposed adjacent to the energy storage unit 10. The shim 300 is disposed alongside the energy storage unit 10 in the Y-axis direction (first direction). The shim 300 is disposed facing the energy storage unit 10 (the spacer 200b in the negative Y-axis direction) in the negative Y-axis direction of the energy storage unit 10, and is a member (shim) that compresses the energy storage unit 10 at a constant pressure in the Y-axis direction. The shim 300 is formed of a metal member such as iron, stainless steel, plated steel plate, aluminum, or aluminum alloy, but may also be formed of a non-metallic member with high strength (hardness), such as ceramics or high-hardness resin. In this embodiment, the shim 300 is formed of a single shim, but may also be formed of multiple shims. The thickness of one shim in the Y-axis direction is approximately 0.3 mm to 5 mm, preferably approximately 0.5 mm to 3.5 mm. The thickness and number of shims constituting the shim 300 are appropriately changed depending on the amount of compression of the electricity storage unit 10 in the Y-axis direction when the electricity storage unit 10 is compressed at a constant pressure in the Y-axis direction.

[0037] The case 400 is a substantially rectangular parallelepiped (box-shaped) container (module case) that constitutes the exterior body (housing, outer shell) of the energy storage device 1. The case 400 is arranged outside the energy storage unit 10 and the shim 300, fixes the energy storage unit 10 and the like in predetermined positions, and protects them from impacts and the like. The case 400 is a metal case made of a metal member such as aluminum, aluminum alloy, stainless steel, iron, or plated steel sheet. In this embodiment, the case 400 is formed (integrally molded) by die-casting aluminum (aluminum die-casting). The case 400 may be made of an insulating member such as any resin material that can be used for the spacer 200 included in the energy storage unit 10.

[0038] 1, case 400 includes case main body 410 constituting the main body of case 400, and lid body 420 constituting the lid of case 400. Case main body 410 is a housing (casing) with an opening 410a formed in the positive direction of the Z axis, and accommodates power storage unit 10 and shim 300. A bottom portion (bottom wall portion) of case main body 410 located at the end in the negative direction of the Z axis is referred to as bottom portion 411, and a side portion (side wall portion) of case main body 410 located at the end in the negative direction of the Y axis is referred to as side portion 412.

[0039] The bottom 411 is a portion of the case 400 (case main body 410) that is arranged on one side in the Z-axis direction (second direction) that intersects with the Y-axis direction (first direction) that is the arrangement direction of the power storage units 10 and the shim 300. The bottom 411 is a portion of the case 400 (case main body 410) that is arranged on one side in the Z-axis direction (second direction) that intersects with the Y-axis direction (first direction) that is the arrangement direction of the power storage units 10 and the shim 300. The bottom 411 is arranged in the Z-axis direction of the power storage unit 10 so as to cover the entire surface of the power storage unit 10 in the Z-axis direction, and supports the power storage unit 10 from the Z-axis direction. The bottom 411 is arranged adjacent to the side portion 412.

[0040] The side portion 412 is a portion of the case 400 (case main body 410) that is disposed in the negative Y-axis direction (one side in the first direction). The side portion 412 is a short side wall (short side wall of the case 400) of the case main body 410 in the negative Y-axis direction. The side portion 412 is disposed with its main surface (the surface with the largest area) facing the Y-axis direction, and is a flat, rectangular wall portion that is parallel to the XZ plane and forms a side surface (short side surface) of the case main body 410 in the negative Y-axis direction. The side portion 412 is a wall portion that rises in the positive Z-axis direction from the end of the bottom portion 411 in the negative Y-axis direction, and is disposed opposite the shim 300 in the Y-axis direction.

[0041] The lid 420 is a flat, rectangular member that closes the opening 410a of the case body 410. The opening 410a is a rectangular opening that is elongated in the Y-axis direction when viewed from the Z-axis direction and is disposed at a position opposite the bottom 411 of the case body 410. The opening 410a is large enough to allow the power storage unit 10 and the shim 300 to pass through in the Z-axis direction. After the power storage unit 10 and the shim 300 are inserted through the opening 410a of the case body 410, the case body 410 and the lid 420 are joined together by screwing with bolts or the like, welding, adhesive bonding, or the like. This results in the case 400 having a structure in which the interior is sealed (hermetically sealed). A terminal block for external terminals (positive external terminal and negative external terminal) may be attached to the case body 410, the lid 420, the spacer 200 (200b), or the like, and the external terminals may be disposed on the terminal block.

[0042] Next, the configurations of the energy storage devices 100, the spacers 200 (particularly the spacers 200b), and the shims 300 will be described in detail.

[0043] [1.1 Description of the energy storage element 100] Fig. 3 is a perspective view showing the configuration of an 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.

[0044] As shown in FIG. 3 , the energy storage device 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 the current collectors and the container 110, but these are not shown in the figure (the gaskets are only partially shown). The type of electrolyte is not particularly limited as long as it does not impair the performance of the energy storage device 100, and various types can be selected. The gasket may be made of any insulating material. In addition to the above-mentioned components, the energy storage device 100 may also include spacers disposed on the sides of the electrode assembly, insulating films encasing the electrode assembly, and insulating films (such as shrink tubes) covering the outer surface of the container 110.

[0045] 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 when the pressure inside the container 110 increases excessively, a liquid injection part (not shown) for injecting electrolyte into the container 110, and the like. 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.

[0046] 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 in the negative Z-axis direction. 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 wall portions of the spacers 200 and the case 400 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 portion that forms the bottom surface of the container 110, and is disposed opposite the wall portion of the spacer 200 and the bottom portion 411 of the case 400 in the Z-axis direction. The bottom surface 113 is disposed adjacent to the long side surface 111 and the short side surface 112.

[0047] The terminals 140 are electrode terminals (positive and negative terminals) of the energy storage element 100 and are arranged on the container lid 130. The terminals 140 are arranged protruding 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. 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 made of aluminum, an aluminum alloy, copper, a copper alloy, or the like.

[0048] 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. As the active material used in the positive electrode active material layer and the negative electrode active material layer, any known material capable of absorbing and releasing charge-transporting ions can be used. 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 in which electrode plates are folded in an accordion-like shape.

[0049] The current collectors are conductive current collecting members (positive and negative current collectors) that are electrically and mechanically connected to the terminal 140 and the electrode body. The positive current collector is made of aluminum or an aluminum alloy, etc., like the positive current collector foil of the positive electrode plate of the electrode body, and the negative current collector is made of copper or a copper alloy, etc., like the negative current collector foil of the negative electrode plate of the electrode body.

[0050] 1.2 Description of spacer 200b Next, the configuration of spacer 200b of spacer 200 will be described in detail. FIG. 4 is a perspective view showing the configuration of spacer 200 (spacer 200b) according to this embodiment. FIG. 4 shows an enlarged view of spacer 200b located at the end of energy storage unit 10 in the negative Y-axis direction, as shown in FIG. 2. Spacer 200b located at the end of energy storage unit 10 in the positive Y-axis direction may not include protruding wall portion 236, which will be described later, but otherwise has the same configuration as spacer 200b located at the end of energy storage unit 10 in the negative Y-axis direction. For this reason, hereinafter, spacer 200b located at the end of energy storage unit 10 in the negative Y-axis direction will be illustrated, and the configuration of spacer 200b will be described in detail.

[0051] 4, the spacer 200b has a shape in which the positive half of the spacer 200b in the X-axis direction and the negative half of the spacer 200b in the X-axis direction 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 wall 220, a spacer protrusion 230, and a pair of legs 240.

[0052] The spacer main 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 main body 210 is disposed in the negative Y-axis direction of the energy storage element 100 that is located at the end of the energy storage unit 10 in the negative Y-axis direction. The spacer main body 210 is disposed opposite the long side surface 111 in the Y-axis direction of the container 110 of the energy storage element 100, covering the entire surface of the long side surface 111 that faces the spacer main body 210, and in contact with the long side surface 111. The surface of the spacer main body 210 in the positive Y-axis direction is provided with a plurality of protrusions (not shown) that form flow paths for a refrigerant (gas such as air or liquid, etc.) that flows between the spacer main body 210 and the energy storage element 100.

[0053] The spacer wall portions 220 are walls arranged on both sides of the energy storage device 100 in the Z-axis direction and both sides of the energy storage device 100 in the X-axis direction. The spacer wall portions 220 include spacer wall portions 221 arranged on both sides of both ends of the energy storage device 100 in the Z-axis direction in the X-axis direction, and spacer wall portions 222 arranged on both ends of the energy storage device 100 in the X-axis direction in the X-axis direction (see FIG. 6). The spacer wall portions 221 are flat plate-shaped portions parallel to the XY plane protruding in the positive Y-axis direction from both Z-axis direction end edges at both ends of the spacer main body portion 210 in the X-axis direction, and are arranged opposite the container lid portion 130 and the bottom surface 113 of the container 110 of the energy storage device 100 in the Z-axis direction. The spacer wall portions 222 are flat plate-shaped portions parallel to the YZ plane protruding in the positive Y-axis direction from both X-axis direction end edges at both ends of the spacer main body portion 210 in the Z-axis direction, and are arranged opposite a pair of short side surfaces 112 of the container 110 of the energy storage device 100 in the X-axis direction. In this way, the spacer walls 220 (221 and 222) are arranged to cover the four corners located at both ends in the Z-axis direction and both ends in the X-axis direction of the energy storage device 100. In this way, the spacer 200b holds the energy storage device 100.

[0054] The spacer protrusion 230 is a protrusion that protrudes from the spacer main body 210 in the negative direction of the Y axis. The spacer protrusion 230 protrudes toward the shim 300. The spacer protrusion 230 is disposed facing the shim 300 in the Y axis direction and in contact with the shim 300. The spacer protrusion 230 is a portion of the energy storage unit 10 that receives a constant pressure load from the shim 300. In this embodiment, five spacer protrusions 230 that protrude from the spacer main body 210 in the negative direction of the Y axis are arranged side by side at intervals in the X axis direction. The five spacer protrusions 230 are also referred to as spacer protrusion 231, spacer protrusion 232, spacer protrusion 233, spacer protrusion 234, and spacer protrusion 235, in that order, from the spacer protrusion 230 at the end in the positive direction of the X axis to the spacer protrusion 230 at the end in the negative direction of the X axis.

[0055] The spacer protrusions 230 (231 to 235) are protrusions that protrude in the negative Y-axis direction from the surface of the spacer main body 210 facing the negative Y-axis direction and are long in the Z-axis direction. When manufacturing the energy storage device 1, a manufacturing device for the energy storage device 1 is inserted into the gaps between the spacer protrusions 230 (231 to 235) to hold the energy storage unit 10 and insert the energy storage unit 10 into the case 400 (case main body 410) in a state where the energy storage unit 10 is compressed in the Y-axis direction. The spacer protrusions 230 (231 to 235) have multiple recesses, each recessed in the surface facing the negative Y-axis direction, arranged side by side in the Z-axis direction (and the X-axis direction), but the arrangement position and number of the recesses are not limited.

[0056] In this embodiment, the spacer protrusion 233 includes a protrusion wall 233a, a protrusion wall 233b, and a pair of protrusion walls 233c, and includes a protrusion wall 236 within a recess surrounded by these walls. The protrusion wall 233a is disposed in the center of the spacer protrusion 233 in the Z-axis direction, and is a plate-like wall parallel to the XY plane and extending in the Y-axis direction. The protrusion wall 233b is disposed in the positive direction of the Z-axis from the protrusion wall 233a, and is a plate-like wall parallel to the XY plane and extending in the Y-axis direction. The pair of protrusion walls 233c are disposed on both sides of the protrusion wall 233a and the protrusion wall 233b in the X-axis direction, and are plate-like walls extending in the Y-axis direction. The protrusion wall 233c is inclined with respect to the YZ plane, but may be disposed parallel to the YZ plane. The protruding wall portion 233a, the protruding wall portion 233b and the pair of protruding wall portions 233c have the same length in the Y-axis direction.

[0057] The protrusion wall 236 is disposed between the protrusion wall 233a and the protrusion wall 233b, and is a plate-like wall that is parallel to the XY plane and extends in the Y-axis direction. The protrusion wall 236 is disposed closer to the protrusion wall 233a than the protrusion wall 233b. Both ends of the protrusion wall 236 in the X-axis direction are connected to the pair of protrusion walls 233c. The protrusion wall 236 is shorter in length in the Y-axis direction than the protrusion walls 233a, 233b, and 233c, and is disposed at a position recessed in the positive Y-axis direction than the protrusion walls 233a, 233b, and 233c. The protrusion wall 236 may be disposed closer to the protrusion wall 233b than the protrusion wall 233a. The end of the protrusion wall 236 in the X-axis direction may be spaced apart from the protrusion wall 233c. The protrusion wall 236 may have the same length in the Y-axis direction as the protrusion walls 233a, 233b, and 233c.

[0058] With this configuration, a recess 237 is formed in the spacer protrusion 233, surrounded by the protrusion wall 236, the protrusion wall 233a, and the pair of protrusion wall portions 233c. The recess 237 is a recess formed by recessing the surface of the spacer protrusion 233 facing the negative Y-axis direction in the positive Y-axis direction. In other words, the recess 237 is formed in the spacer 200b, which is a holder that holds the energy storage device 100. The recess 237 is formed in the spacer protrusion 230 (233) of the spacer 200b that protrudes toward the shim 300. A protrusion 312 of the shim 300, which will be described later, is inserted into the recess 237 (see FIGS. 6 and 7A).

[0059] The recess 237 is disposed at the center of the spacer protrusion 233 in the Z-axis direction. The recess 237 is preferably disposed at the center of the Z-axis direction when the entire length of the spacer 200b in the Z-axis direction is divided into thirds, and more preferably disposed at the center of the Z-axis direction when the entire length of the spacer 200b in the Z-axis direction is divided into fifths. Since the spacer protrusion 233 is located at the center of the spacer 200b in the X-axis direction, the recess 237 is disposed at the center of the spacer 200b in the X-axis direction. The recess 237 is preferably disposed at the center of the X-axis direction when the entire length of the spacer 200b in the X-axis direction is divided into thirds, and more preferably disposed at the center of the X-axis direction when the entire length of the spacer 200b in the X-axis direction is divided into fifths. As a result, the recess 237 is disposed at the center of the spacer 200b when viewed from the Y-axis direction. In other words, the recess 237 is a recess in which the surface of the spacer 200b in the negative Y-axis direction at the center is recessed in the positive Y-axis direction.

[0060] The pair of legs 240 are protrusions (convex portions) that protrude in the negative Z-axis direction from both ends in the X-axis direction at the negative Z-axis direction ends of the spacer main body 210 and extend in the Y-axis direction. The pair of legs 240 are legs of the spacer 200b, and are placed on the bottom 411 of the case 400 to support the spacer 200b relative to the case 400. The number, shape, size, etc. of the legs 240 are not particularly limited as long as they are configured to support the spacer 200b.

[0061] [1.3 Explanation of Sim 300] Next, the configuration of the shim 300 and the positional relationship between the shim 300, the energy storage unit 10 (spacer 200b), and the case 400 (case main body 410) will be described in detail. FIG. 5 is a perspective view showing the configuration of the shim 300 according to this embodiment. FIG. 5 shows an enlarged view of the shim 300 shown in FIG. 2. FIG. 6 is a cross-sectional view showing the configurations of the shim 300 and spacer 200b according to this embodiment. FIG. 6 shows a cross-section of the spacer 200b shown in FIG. 4 and the shim 300 shown in FIG. 5, taken along a plane that includes line VI-VI passing through the center position in the X-axis direction and is parallel to the YZ plane. FIG. 7A is a cross-sectional view showing the positional relationship between the shim 300 according to this embodiment, the energy storage unit 10 (spacer 200b), and the case 400 (case main body 410). Fig. 7A shows a cross section of the configuration in which the energy storage unit 10 and the shim 300 are arranged in the case main body 410 shown in Fig. 1, taken along a plane that includes line VIIA-VIIA passing through the center position in the X-axis direction and is parallel to the YZ plane. Fig. 7B is a cross section showing the configuration around the shim end portion 330 of the shim 300 according to this embodiment. Fig. 7B shows an enlarged view of the configuration around the shim end portion 330 of the shim 300 shown in Fig. 7A.

[0062] As shown in FIG. 5, the shim 300 includes a shim main body 310, a shim protruding portion 320, and a shim end portion 330.

[0063] [1.3.1 Description of the shim body 310] The shim main body 310 is a flat, rectangular portion constituting the main body of the shim 300 and is disposed parallel to the XZ plane. The shim main body 310 is a flat portion oriented in the Y-axis direction with a constant thickness in the Y-axis direction. As shown in FIG. 7A , the shim main body 310 is disposed in the negative Y-axis direction of the energy storage unit 10 and is in contact with the energy storage unit 10. Specifically, the shim main body 310 is disposed in the negative Y-axis direction of the spacer protrusion 230 of the spacer 200b included in the energy storage unit 10 so as to cover almost the entire surface of the spacer protrusion 230 when viewed from the Y-axis direction. The shim main body 310 is disposed opposite the spacer protrusion 230 in the Y-axis direction and in contact with the spacer protrusion 230. The shim main body 310 is disposed in the positive Y-axis direction of the side portion 412 of the case body 410 and is disposed opposite the side portion 412 in the Y-axis direction and in contact with the side portion 412. As a result, the shim main body 310 is disposed between the spacer protruding portion 230 of the spacer 200b and the side portion 412 of the case main body 410, in a state where it is sandwiched between the spacer protruding portion 230 and the side portion 412.

[0064] The shim main body 310 includes a through hole 311 and a protrusion 312. The through hole 311 is a rectangular through hole that penetrates the shim main body 310 in the Y-axis direction (first direction), which is the arrangement direction of the power storage unit 10 and the shim 300. The through hole 311 is disposed in the center (the center in the X-axis direction and the center in the Z-axis direction) of the shim 300 (shim main body 310) when viewed from the Y-axis direction. As shown in FIGS. 6 and 7A, the through hole 311 is disposed opposite the spacer protrusion 233 of the spacer 200b.

[0065] The protrusion 312 is a protrusion that protrudes in the positive direction of the Y axis from the end (edge) of the through hole 311. The protrusion 312 protrudes from the end of the through hole 311 in the Z axis direction (second direction), which is a direction intersecting the Y axis direction (first direction). In this embodiment, the protrusion 312 protrudes in the positive direction of the Y axis from the end (edge) of the through hole 311 in the positive direction of the Z axis. The protrusion 312 is disposed in the center (the center in the X axis direction and the center in the Z axis direction) of the shim 300 (shim main body 310) when viewed from the Y axis direction. The protrusion 312 is preferably disposed in a central portion in the Z axis direction when the entire length of the shim 300 in the Z axis direction is divided into thirds, and more preferably disposed in a central portion in the Z axis direction when the entire length of the shim 300 in the Z axis direction is divided into fifths. The protrusion 312 is preferably positioned at the center of the X-axis direction when the total length of the shim 300 in the X-axis direction is divided into thirds, and more preferably positioned at the center of the X-axis direction when the total length of the shim 300 in the X-axis direction is divided into fifths.

[0066] The protrusion 312 is a plate-like portion that is rectangular when viewed from the Z-axis direction and parallel to the XY plane. In this embodiment, the shape of the protrusion 312 when viewed from the Z-axis direction is the same as or smaller than the shape of the through-hole 311 when viewed from the Y-axis direction. In other words, the area of ​​the surface of the protrusion 312 facing the Z-axis direction (second direction) is equal to or smaller than the opening area of ​​the through-hole 311. The thickness of the protrusion 312 in the Z-axis direction is the same as the thickness of the portion of the shim main body 310 surrounding the through-hole 311 in the Y-axis direction. The protrusion 312 having such a configuration can be formed by cutting out the central portion of the shim main body 310. The protrusion 312 can be formed by making cuts in the periphery of a rectangular portion located in the central portion of the shim main body 310 except for the upper edge, and then bending the rectangular portion at the upper edge in the positive direction of the Y-axis.

[0067] As shown in FIGS. 6 and 7A, the protrusion 312 protrudes toward the energy storage unit 10 (spacer 200b). The protrusion 312 protrudes from the end of the through-hole 311 toward the energy storage unit 10 (spacer 200b). As described above, the energy storage unit 10 (spacer 200b) has a recess 237 into which the protrusion 312 is inserted. That is, the recess 237 is formed in the spacer protrusion 233 of the spacer 200b, and the protrusion 312 is inserted into the recess 237. In this embodiment, the width of the recess 237 in the Z-axis direction is the same as or slightly smaller than the thickness of the protrusion 312, or the width of the recess 237 in the X-axis direction is the same as or slightly smaller than the length of the protrusion 312. Therefore, the protrusion 312 is fitted (press-fit) into the recess 237. As a result, protrusion wall 233a is disposed in the negative Z-axis direction of protrusion 312, protrusion wall 236 is disposed in the positive Z-axis direction of protrusion 312, and a pair of protrusion wall portions 233c are disposed on both sides of protrusion 312 in the X-axis direction. Since protrusion 312 has a non-circular shape when viewed in the Y-axis direction, rotation of protrusion 312 with respect to recess 237 is suppressed.

[0068] [1.3.2 Explanation of shim protrusion 320] The shim protrusion 320 is a protrusion that protrudes from the shim main body 310 in the positive direction of the Z axis (the other side in the second direction). The shim protrusion 320 is a substantially rectangular, flat portion when viewed in the Y axis direction. Two shim protrusions 320 are disposed protruding in the positive direction of the Z axis from both ends of the shim main body 310 in the X axis direction. That is, the shim 300 includes two shim protrusions 320 aligned in the X axis direction (a third direction intersecting the first and second directions). As shown in FIG. 7A , the shim protrusion 320 protrudes in the positive direction of the Z axis further than the spacer protrusion 230 of the spacer 200b and further than the side portion 412 of the case main body 410. That is, the shim protrusion 320 protrudes in the positive direction of the Z axis from between the energy storage unit 10 (spacer 200b) and the case main body 410 (side portion 412). Shim protrusion 320 is used as a portion to be grasped by a manufacturing device for power storage device 1 when shim 300 is transported during the manufacture of power storage device 1.

[0069] 1.3.3 Shim End 330 The shim end 330 is a portion of the shim main body 310 that is located in the negative Z-axis direction (one side in the second direction). The shim end 330 is a portion of the shim 300 that extends in the X-axis direction and is located at the end of the shim 300 in the negative Z-axis direction. As shown in FIGS. 7A and 7B , the shim end 330 does not contact the energy storage unit 10. That is, the portion of the end of the shim 300 in the negative Z-axis direction that does not contact the energy storage unit 10 is referred to as the shim end 330. Specifically, the shim end 330 is located at a position that does not face the spacer protrusion 230 in the Y-axis direction, and is thereby located out of contact with the spacer protrusion 230. The shim end 330 is located so as to protrude from the spacer protrusion 230 in the negative Z-axis direction. The shim end 330 is located in the positive Y-axis direction of the side 412 of the case main body 410, faces the side 412 in the Y-axis direction, and is in contact with the side 412. The shim end 330 is disposed apart from the bottom 411 of the case body 410. This will be described in detail below.

[0070] As shown in FIGS. 7A and 7B , the bottom 411 includes a bottom wall 411a and a step portion 411b, and the step portion 411b includes a case end portion 411c. The bottom wall 411a is the bottom wall of the case main body 410 (case 400) and is disposed at the end of the bottom 411 in the negative Z-axis direction. The bottom wall 411a is a flat, rectangular wall portion that is parallel to the XY plane and elongated in the Y-axis direction, and is disposed with its main surface (the surface with the largest area) facing the Z-axis direction. The bottom wall 411a is disposed opposite the energy storage unit 10 in the Z-axis direction. The step portion 411b is disposed at the end of the bottom 411 in the negative Y-axis direction and is a stepped (step-like) portion that extends in the X-axis direction. The step portion 411b protrudes from the side portion 412 in the positive Y-axis direction and is disposed in the negative Z-axis direction of the shim 300. The bottom 411 may have a space that serves as a flow path for a refrigerant (gas such as air or liquid, etc.) that cools the storage element 100, and an opening (through hole) that connects the space to the outside of the case 400.

[0071] In this configuration, the step portion 411b is disposed at a distance from the shim end portion 330 of the shim 300. That is, the case end portion 411c located at the end portion of the step portion 411b in the positive Z-axis direction is disposed at a distance from the shim end portion 330. The case end portion 411c is a connecting portion of the bottom portion 411 with the side portion 412. The case end portion 411c is a corner portion of the inner surface of the bottom portion 411 of the case 400 (case main body 410). The case end portion 411c is an end portion (an end portion in the negative Z-axis direction) of the case 400 (case main body 410) on one side in the Z-axis direction (a second direction) that intersects with the Y-axis direction (a first direction) in which the power storage unit 10 and the shim 300 are arranged. The surface of the case end portion 411c in the positive Z-axis direction has an inclined surface that inclines in the positive Z-axis direction as it approaches the negative Y-axis direction (a curved surface that curves in the positive Z-axis direction). That is, a rounded portion (corner radius) is formed on case end portion 411c, which is the connecting portion of bottom portion 411 with side portion 412.

[0072] In this way, the shim end 330 faces the case end 411c in the Z-axis direction (second direction) and is disposed at a distance from the case end 411c. In other words, the shim 300 is disposed at a distance from the bottom 411 of the case 400. This prevents the shim 300 (shim end 330) from coming into contact with the rounded portion of the bottom 411 (case end 411c).

[0073] [2. Description of Manufacturing Method of Energy Storage Device 1] The energy storage device 1 configured as described above is manufactured by a manufacturing apparatus (not shown) for the energy storage device 1 as follows. First, the manufacturing apparatus stacks a plurality of energy storage elements 100 and a plurality of spacers 200 (200a and 200b) to form an energy storage unit 10. The manufacturing apparatus inserts a jig between the plurality of spacer protrusions 230 provided on the spacer 200b to sandwich and hold the energy storage unit 10 from both sides in the Y-axis direction, and compresses the energy storage unit 10 in the Y-axis direction. In the energy storage element 100, the container 110 may bulge in the Y-axis direction depending on the electrode assembly housed therein and the amount and composition of the electrolyte. The spacer 200 may have a material and shape that allows elastic deformation. The manufacturing apparatus compresses the bulging amounts of the plurality of energy storage elements 100 provided in the energy storage unit 10 and the elastically deformable amount of the spacer 200.

[0074] At this time, the manufacturing device transports the shim 300 by air suction or by gripping the shim protrusion 320, and inserts the convex portion 312 of the shim 300 into the concave portion 237 of the spacer 200b. As a result, the shim 300 is supported (held) by the electricity storage unit 10 (spacer 200b).

[0075] Next, the manufacturing equipment inserts the energy storage unit 10 and the shim 300 into the case body 410 while compressing the energy storage unit 10 in the Y-axis direction. As a result, the energy storage unit 10 and the shim 300 are disposed in the case body 410 with the shim 300 spaced apart from the side portion 412 of the case body 410. Next, the manufacturing equipment releases the compression of the energy storage unit 10. As a result, the bulging portions of the compressed energy storage elements 100 and the elastically deformable portion of the spacer 200 return to their original state, the energy storage unit 10 expands in the Y-axis direction, and the shim 300 comes into contact with the side portion 412 of the case body 410. Because the shim 300 is positioned and held by the spacer 200b, the shim end 330 is spaced apart from the case end 411c. Thereafter, the manufacturing equipment is removed, resulting in the state shown in FIG. 7A.

[0076] Before or after the energy storage unit 10 is inserted into the case body 410, bus bars, bus bar frames, and the like are arranged for the plurality of energy storage elements 100. Then, the case body 410 and the lid 420 are joined together to house the energy storage unit 10 in the case 400, and the energy storage device 1 is manufactured.

[0077] [3 Explanation of effects] As described above, according to the energy storage device 1 of this embodiment, the shim 300 has the convex portion 312 that protrudes toward the energy storage unit 10, and the energy storage unit 10 has the concave portion 237 into which the convex portion 312 is inserted. As a result, by inserting the convex portion 312 of the shim 300 into the concave portion 237 of the energy storage unit 10, the shim 300 can be positioned relative to the energy storage unit 10, and therefore, positional deviation of the shim 300 can be suppressed.

[0078] If misalignment of the shim 300 can be suppressed, even when a rounded portion (corner radius) is formed on the bottom 411 of the case 400, the shim 300 can be prevented from coming into contact with the rounded portion. This prevents the shim 300 from being disposed in an inclined state, thereby preventing problems such as scraping of the case 400 by the shim 300 or deterioration of vibration resistance. If the shim 300 is inserted into the case 400 without being positioned relative to the power storage unit 10, the shim 300 may move (fall) in the negative Z-axis direction relative to the power storage unit 10 and come into contact with the rounded portion on the bottom 411 of the case 400. By inserting the shim 300 into the case 400 together with the power storage unit 10 while positioning the shim 300 relative to the power storage unit 10, the shim 300 can be prevented from moving (falling) in the negative Z-axis direction relative to the power storage unit 10 and coming into contact with the rounded portion.

[0079] The shim body 310 of the shim 300 receives the load from the electricity storage unit 10 at a location different from the protrusion 312 that performs positioning. By separating the portion of the shim 300 that receives the load from the portion that performs positioning, it is possible to suppress the positioning of the shim 300 from affecting the load (constant pressure load) that the shim 300 receives.

[0080] The energy storage unit 10 includes an insulating spacer 200b disposed between the shim 300 and the energy storage element 100, and the recess 237 is formed in the spacer 200b. Thus, by forming the recess 237 in the insulating spacer 200b disposed between the shim 300 and the energy storage element 100, the recess 237 can be easily formed in the energy storage unit 10. The insulating spacer 200b can insulate between the energy storage element 100 and the shim 300, and by inserting the protrusion 312 of the shim 300 into the recess 237 of the spacer 200b, the recess 237 of the spacer 200b can actively insulate the protrusion 312 of the shim 300.

[0081] By forming the recesses 237 in the spacer 200b, which is a holder for holding the energy storage elements 100, the recesses 237 can be easily formed in the energy storage unit 10. The spacer 200b (holder) can position the energy storage elements 100 by holding them, and can also position the shim 300 by inserting the protrusions 312 of the shim 300 into the recesses 237. This allows the spacer 200b (holder) to position both the energy storage elements 100 and the shim 300.

[0082] The protrusion 312 of the shim 300 protrudes from the end of the through-hole 311 of the shim 300 toward the energy storage unit 10. This makes it possible to confirm (visually, by image processing, etc.) the position of the recess 237 of the energy storage unit 10 from the through-hole 311 of the shim 300, and to confirm (visually, by image processing, etc.) whether the protrusion 312 of the shim 300 has been inserted into the recess 237 of the energy storage unit 10.

[0083] The convex portion 312 of the shim 300 protrudes from the end of the through hole 311 in the Z-axis direction (second direction), and the area of ​​the face of the convex portion 312 facing in the Z-axis direction (second direction) is equal to or less than the opening area of ​​the through hole 311 of the shim 300. Because the area of ​​the face of the convex portion 312 of the shim 300 is equal to or less than the opening area of ​​the through hole 311 in this way, the convex portion 312 can be easily formed in the shim 300 by cutting and raising the shim 300. By forming the convex portion 312 in the shim 300 by cutting and raising, it is possible to reduce the amount of material used compared to forming the convex portion by protruding the end of the shim 300 and bending the protruding portion.

[0084] The recess 237 of the energy storage unit 10 is formed in the spacer protruding portion 230 that protrudes toward the shim 300 of the energy storage unit 10. By forming the recess 237 in the spacer protruding portion 230 of the energy storage unit 10 in this manner, the spacer protruding portion 230 can be used to form the recess 237.

[0085] By arranging the protrusion 312 of the shim 300 in the center of the shim 300, the shim 300 can be stably positioned relative to the electricity storage unit 10.

[0086] By arranging shim 300 at a distance from bottom 411 of case 400, even if bottom 411 of case 400 has a rounded portion formed thereon, shim 300 can be prevented from coming into contact with the rounded portion.

[0087] [4 Explanation of Variations] Although 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.

[0088] (Variation 1) In the above embodiment, the protrusion 312 of the shim 300 protrudes from the end of the through-hole 311 in the positive direction of the Z axis, but it may protrude from any position in the through-hole 311. Fig. 8 is a perspective view showing the configuration of a shim 301 according to a first modification of this embodiment. Fig. 8 is a view corresponding to Fig. 5.

[0089] As shown in FIG. 8, the shim 301 of this modification differs from the through hole 311 of the shim 300 of the above embodiment in that the through hole 311 is arranged in the positive direction of the Z axis of the protrusion 312. In other words, in this modification, the protrusion 312 protrudes from the end (edge) of the through hole 311 in the negative direction of the Z axis. The protrusion 312 of this modification can be formed by cutting and raising the center of the shim main body 310, as in the above embodiment. The other configurations of this modification are the same as those of the above embodiment, so a description thereof will be omitted. This modification can also achieve the same effects as the above embodiment.

[0090] In this modification, a protrusion 312 may protrude from the X-axis direction end (edge) of the through-hole 311. In this case, the protrusion 312 may have a shape that extends in the Z-axis direction, and the recess 237 of the spacer 200b is formed at a position, with a size and a shape that correspond to the protrusion 312.

[0091] (Other variations) In the above embodiment, the shim 300 has the through hole 311 and the protrusion 312 protrudes from the end of the through hole 311, but this is not limiting. The protrusion 312 may protrude from a position different from the through hole 311. In this case, the shim 300 does not need to have the through hole 311.

[0092] In the above embodiment, in shim 300, the area of ​​the surface of convex portion 312 facing the Z-axis direction is equal to or smaller than the opening area of ​​through hole 311, but it may be larger than the opening area of ​​through hole 311. The area of ​​the surface of convex portion 312 facing the Z-axis direction may be increased by forming convex portion 312 by cutting and then compressing it in the Z-axis direction, or convex portion 312 does not have to be formed by cutting. The shape of convex portion 312 is not particularly limited, and may be a curved plate rather than a flat plate, or may be a rod shape such as a cylindrical, elliptical cylinder, or long cylindrical cylinder.

[0093] In the above embodiment, the protrusion 312 is disposed in the center of the shim 300, but it may be disposed at an end of the shim 300. The recess 237 (protrusion wall 236) may be disposed at the end of the spacer protrusion 233 in the Z axis direction. In this case, the protrusion 312 may be disposed at the end of the shim 300 in the Z axis direction. The recess 237 (protrusion wall 236) may be disposed in any of the spacer protrusions 231, 232, 234, and 235. In this case, the protrusion 312 may be disposed at the end of the shim 300 in the X axis direction. A plurality of recesses 237 (protrusion wall 236) may be formed in the spacer 200b, and the shim 300 may include a plurality of protrusions 312. In this way, the positions and number of the recesses 237 (protrusion wall 236) and the positions and number of the protrusions 312 are not limited.

[0094] In the above embodiment, the shim 300 is arranged at a distance from the bottom 411 of the case 400, but as long as the shim 300 can be positioned relative to the energy storage unit 10, the shim 300 may be arranged in contact with the bottom 411.

[0095] In the above embodiment, the spacer 200b includes the spacer protrusion 233, and the recess 237 is formed in the spacer protrusion 233; however, this is not limiting. The recess 237 may be formed in a position of the spacer 200b different from the spacer protrusion 233. In this case, the spacer 200b does not need to include the spacer protrusion 233. The recess 237 may be formed in a member (such as the energy storage element 100) of the energy storage unit 10 different from the spacer 200b. The protrusion 312 etc. of the shim 300 are arranged at positions corresponding to the positions of the recess 237.

[0096] In the above embodiment, the recess 237 of the spacer 200b may have any shape or size as long as the protrusion 312 of the shim 300 can be inserted therein. The protrusion wall 236 may be a curved plate-like portion or a rod-like portion instead of a flat portion. A recess formed by the protrusion wall 233a, the protrusion wall 233b, and a pair of protrusion wall portions 233c without the protrusion wall 236 may be referred to as the recess 237. Although the recess 237 is surrounded by walls on both sides in the X-axis direction and on both sides in the Z-axis direction, either wall may not be provided. The protrusion 312 of the shim 300 may be inserted into the recess 237 of the spacer 200b without being fitted (press-fitted) therein.

[0097] In the above embodiment, the spacer wall 220 of the spacer 200b has a plurality of walls, but this is not limiting. The spacer 200b may be a holder that holds the energy storage elements 100 by having at least one of the walls of the spacer wall 220, or may be a plate-shaped (sheet-shaped) spacer that does not hold the energy storage elements 100 by not having all of the walls.

[0098] In the above embodiment, the shim 300 is provided with two shim protrusions 320, but the number of shim protrusions 320 is not particularly limited.

[0099] In the above embodiment, bottom 411 of case 400 has step 411b, but it does not have to have step 411b. In this case, case end 411c may be the connection portion between bottom wall 411a and side portion 412.

[0100] In the above embodiment, the height of the case body 410 in the Z-axis direction is not particularly limited. That is, the case body 410 may be configured to have a sufficient height in the Z-axis direction to accommodate the power storage unit 10, and the power storage unit 10 may not protrude from the case body 410 in the positive direction of the Z-axis. The case body 410 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 420 may have a height of about one-third or half of the power storage unit 10 in the Z-axis direction, and to accommodate a portion of the power storage unit 10 in the positive direction of the Z-axis.

[0101] In the above embodiment, a plurality of power storage units 10 arranged in the X-axis direction may be housed inside the case 400. A plurality of power storage units 10 arranged in the Y-axis direction may be housed inside the case 400. When a plurality of power storage units 10 are housed in the case 400, 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.

[0102] In the above embodiment, the case 400 is provided with the case body 410 and the lid 420, but the lid 420 may not be provided.

[0103] In the above embodiment, the energy storage unit 10 may not include the spacer 200a or the spacer 200b. When the energy storage unit 10 does not include the spacer 200b, it is sufficient that a member of the energy storage unit 10, such as the energy storage element 100, other than the spacer 200b, includes the recess 237.

[0104] Any combination of the components of the above-described embodiment and its modifications is also included within the scope of the present invention. [Industrial Applicability]

[0105] The present invention can be applied to an electricity storage device including an electricity storage element such as a lithium ion secondary battery. [Explanation of symbols]

[0106] 1. Energy storage device 10 Energy storage unit 100 Energy storage element 110 Container 140 terminals 200, 200a, 200b spacers 210 Spacer body 220, 221, 222 Spacer wall 230, 231, 232, 233, 234, 235 Spacer protrusions 233a, 233b, 233c, 236 Projection wall 237 Recess 300, 301 Sim 310 Shim body 311 Through hole 312 Convex part 320 Shim protrusion 330 Shim end 400 cases 410 Case body 411 Bottom 411a Bottom wall 411b Step 411c Case end 412 Side 420 Lid

Claims

1. a power storage unit including a power storage element; a shim disposed adjacent to the power storage unit, the shim includes a protrusion that protrudes toward the electricity storage unit, The power storage unit has a recess into which the protrusion is inserted. Energy storage device.

2. the power storage unit further includes an insulating spacer disposed between the shim and the power storage element; The recess is formed in the spacer. The power storage device according to claim 1 .

3. the shim includes a through-hole that penetrates in a first direction that is an arrangement direction of the power storage unit and the shim, The protrusion protrudes from an end of the through hole toward the electricity storage unit. The electricity storage device according to claim 1 or 2.

4. the protrusion protrudes from an end of the through hole in a second direction that is a direction intersecting the first direction, The area of ​​the surface of the protrusion facing the second direction is equal to or less than the opening area of ​​the through hole. The power storage device according to claim 3 .

5. the power storage unit includes a protrusion that protrudes toward the shim, The recess is formed in the protrusion. The electricity storage device according to claim 1 or 2.

6. The protrusion is disposed in the center of the shim. The electricity storage device according to claim 1 or 2.

7. a case that houses the power storage unit and the shim; The shim is spaced apart from the bottom of the case. The electricity storage device according to claim 1 or 2.

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