Power storage device

Abstract

This power storage device comprises: a power storage unit comprising a power storage element; a shim disposed adjacent to the power storage unit; and a case accommodating the power storage unit and the shim. The case comprises a case end section which is an end section thereof on one side in a second direction that is a direction crossing a first direction that is the direction in which the power storage unit and the shim are lined up. The shim comprises: a flat plate-shaped shim body section; and a shim end section that is arranged on one side of the shim body section in the second direction and that faces the case end section in the second direction. The case end section comprises: a first case end portion; and a second case end portion disposed on one side of the first case end portion in the first direction. The second case end portion is located to the other side of the first case end portion in the second direction. The shim end section comprises: a first shim end portion that faces the first case end portion in the second direction; and a second shim end portion that faces the second case end portion in the second direction. The first shim end portion is located to one side of the second shim end portion in the second direction.

Description

Power storage device

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

[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.

[0003] Japanese Patent Application Laid-Open No. 2021-44183

[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), if 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.

[0006] and a case that houses the power storage unit and the shim. The case has a case end that is an end on one side in a second direction that intersects with a first direction in which the power storage unit and the shim are arranged. The shim has a flat shim main body and a shim end that is arranged on the one side of the shim main body in the second direction and faces the case end in the second direction. The case end includes a first case end and a second case end that is arranged on the one side of the first case end in the first direction. The second case end is located on the other side of the first case end in the second direction. The shim end includes a first shim end that faces the first case end in the second direction and a second shim end that faces the second case end in the second direction. The first shim end is located on the one side of the second shim end in the second direction.

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

[0008] FIG. 1 is a perspective view showing a configuration of an energy storage device according to an embodiment. FIG. 2 is an exploded perspective view showing an energy storage element, a spacer, and a shim of an energy storage unit included in the energy storage device according to an embodiment. FIG. 3 is a perspective view showing a configuration of an energy storage element according to an embodiment. FIG. 4 is a perspective view showing a configuration of a spacer according to an embodiment. FIG. 5A is a perspective view showing a configuration of a shim according to an embodiment. FIG. 5B is a cross-sectional view showing a configuration of a shim end portion of a shim according to an embodiment. FIG. 6A is a cross-sectional view showing a positional relationship between a shim, an energy storage unit (spacer), and a case (case main body) according to an embodiment. FIG. 6B is a cross-sectional view showing a shim end portion and its surrounding configuration of a shim according to an embodiment. FIG. 7 is a cross-sectional view showing a shim end portion and its surrounding configuration of a shim according to a first modification of the embodiment. FIG. 8 is a cross-sectional view showing a shim end portion and its surrounding configuration of a shim according to a second modification of the embodiment. FIG. 9 is a cross-sectional view showing a shim end portion and its surrounding configuration of a shim according to a third modification of the embodiment. FIG. 10 is a cross-sectional view showing a shim end portion and its surrounding configuration of a shim according to a fourth modification of the embodiment. FIG. 11 is a front view showing the configuration of a shim according to the fifth modification of the embodiment.

[0009] (1) An energy storage device according to one aspect of the present invention comprises: an energy storage unit having an energy storage element; a shim arranged adjacent to the energy storage unit; and a case that houses the energy storage unit and the shim. The case has a case end that is an end on one side in a second direction that intersects a first direction in which the energy storage unit and the shim are arranged. The shim has a flat shim main body portion and a shim end that is arranged on one side of the shim main body portion in the second direction and faces the case end in the second direction. The case end comprises a first case end and a second case end that is arranged on one side of the first case end in the first direction. The second case end is located on the other side of the first case end in the second direction. The shim end comprises a first shim end that faces the first case end in the second direction and a second shim end that faces the second case end in the second direction. The first shim end is located on the one side of the second shim end in the second direction.

[0010] In one aspect of the present invention, in an energy storage device, the second case end of the case is located on the other side of the first case end in the second direction, and the first shim end facing the first case end of the shim is located on one side of the second shim end facing the second case end in the second direction. Thus, the positional relationship between the first shim end and the second shim end of the shim in the second direction corresponds to the positional relationship between the first case end and the second case end of the case. In other words, even if a portion of the case end is located further in the second direction than another portion, the shim end is shaped to correspond to the case end in the second direction. This prevents the shim from being tilted even when the shim end contacts the case end, thereby preventing the shim from being misaligned.

[0011] (2) In the energy storage device described in (1) above, the case end may have an inclined surface that slopes toward the other side of the second direction as it approaches one side of the first direction, thereby forming the first case end and the second case end, and the shim end may have an inclined surface that slopes toward the other side of the second direction as it approaches one side of the first direction, thereby forming the first shim end and the second shim end.

[0012] According to the energy storage device described in (2) above, the case end has an inclined surface that slopes toward one side in the first direction and toward the other side in the second direction, and the shim end has an inclined surface that slopes toward one side in the first direction and toward the other side in the second direction. In this way, even when an inclined surface is formed on the case end, the shim end has an inclined surface that slopes in the same direction as the inclined surface of the case end. This prevents the shim from being positioned in an inclined state even if the shim end comes into contact with the case end.

[0013] (3) In the energy storage device described in (1) or (2) above, the case may have a side portion arranged on one side of the first direction and a bottom portion arranged on one side of the second direction, and the case end portion may be a connection portion of the bottom portion with the side portion.

[0014] According to the energy storage device described in (3) above, the case end is a portion of the bottom of the case that connects to the side. That is, the case end has a rounded portion (corner radius) formed at the corner of the bottom of the case. In this way, even if the bottom of the case has a rounded portion, it is possible to prevent the shim end from contacting the rounded portion and being positioned in an inclined state.

[0015] (4) In the energy storage device described in (3) above, the bottom may be arranged on the other side of the shim end in the first direction and may have a convex portion that protrudes to the other side in the second direction.

[0016] According to the energy storage device described in (4) above, the bottom of the case has a protrusion on the other side of the shim end in the first direction, which restricts the shim end from moving to the other side in the first direction, thereby preventing the shim from being positioned in an inclined state.

[0017] (5) In the energy storage device according to any one of (1) to (4) above, the shim main body may be in contact with the energy storage unit, and the shim end portion may not be in contact with the energy storage unit.

[0018] According to the energy storage device described in (5) above, the shim main body contacts the energy storage unit, but the shim end does not contact the energy storage unit. In other words, by arranging the shim main body at a position on the shim that contacts the energy storage unit, the flat shim main body bears the load from the energy storage unit. Because the shim end may not be able to bear the load from the energy storage unit, the shim end is arranged at a position that does not contact the energy storage unit. In this way, by separating the portion of the shim that receives the load (the shim main body) from the portion that suppresses misalignment (the shim end), it is possible to suppress the influence on the load (constant pressure load) that the shim receives.

[0019] (6) In the energy storage device described in any one of (1) to (5) above, the shim may have two protrusions that protrude from the shim main body to the other side of the second direction and are aligned in a third direction that intersects the first direction and the second direction, and the shim end may be positioned between the two protrusions in the third direction.

[0020] According to the energy storage device described in (6) above, the shim end is disposed in the third direction between two protrusions of the shim that protrude toward the other side of the second direction. That is, the shim has two protrusions that protrude from the shim body toward the other side of the second direction and are aligned in the third direction for use during transportation, etc. Therefore, the shim end is disposed between the two protrusions in the third direction. With this configuration, when two shims are aligned in the second direction, the shim end of one shim located on the other side of the second direction can be disposed between the two protrusions of one shim located on one side of the second direction. This allows the shim end of one shim to be disposed between the two protrusions of the other shim when multiple shims are continuously manufactured in the second direction by punching or the like. Therefore, the material between the two protrusions of one shim can be used for the shim end of the other shim, thereby reducing material usage.

[0021] 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.

[0022] 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 the spacer, the thickness direction of the shim, the thickness direction (flattening direction) of the energy storage element or the 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 opposing 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-down direction. The X-axis direction, Y-axis direction, and Z-axis direction intersect 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.

[0023] 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 term "X-axis direction" simply refers to both or either of the positive X-axis direction and the negative X-axis direction. The terms "one side" and "the other side" refer to one and the other of the positive X-axis direction and the negative X-axis direction. 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 direction. The same applies to the Y-axis and Z-axis directions. Hereinafter, the Y-axis direction will also be referred to as the "first direction," the 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 or orientations are not strictly the same. 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 description, 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 more preferable, and 1×10 １０ More preferably, it is Ωm or more.

[0024] (Embodiment) [1 Description of Energy Storage Device 1] First, a schematic configuration of the energy storage device 1 according to this embodiment will be described. FIG. 1 is a perspective view showing the configuration of the energy storage device 1 according to this embodiment. FIG. 1 shows the energy storage device 1 in a state where a lid 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 this 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.

[0025] The power storage device 1 is a device that can charge electricity from an external source and discharge electricity to an external source. The power storage device 1 is used for power storage purposes, power supply purposes, etc. The power storage device 1 is used as a battery for driving or starting the engine of a mobile object such as an automobile, a motorcycle, a personal watercraft, a ship, a snowmobile, an agricultural machine, a construction machine, an automatic guided vehicle (AGV), or a railway vehicle for an electric railway. Examples of the automobile include an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a fossil fuel (gasoline, diesel, liquefied natural gas, etc.) vehicle. Examples of the railway vehicle for the electric railway include a train, a monorail, a linear motor car, and a hybrid train equipped with both a diesel engine and an electric motor. The power storage device 1 can also be used as a stationary battery for home or business use.

[0026] 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 (positive external terminal and 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.

[0027] 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 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-constrained type module that does not include any restraining members (end plates, side plates, etc.) that restrain the plurality of energy storage elements 100 and spacers 200 in the Y-axis direction.

[0028] The energy storage element 100 is a secondary battery (single cell) capable of charging and discharging electricity, and more specifically, a non-aqueous electrolyte secondary battery such as a lithium-ion secondary battery. The energy storage element 100 has a rectangular parallelepiped shape (square or rectangular) that is flattened in the Y-axis direction. In this embodiment, a plurality of energy storage elements 100 are arranged side by side in the Y-axis direction. However, the number of arranged energy storage elements 100 is not particularly limited and may be one, several tens of energy storage elements 100, or more. The size and shape of the energy storage element 100 are also not particularly limited and may be an elongated cylinder, an elliptical cylinder, a cylindrical shape, a polygonal prism shape other than a rectangular parallelepiped, or the like. The energy storage element 100 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, or may be a capacitor. The energy storage element 100 may be a primary battery instead of a secondary battery. The energy storage element 100 may be a battery using a solid electrolyte. The energy storage element 100 may be a pouch-type energy storage element.

[0029] The spacer 200 is a flat member in the Y-axis direction that is arranged alongside the energy storage element 100 in the Y-axis direction and provides insulation and / or thermal insulation between the energy storage element 100 and other components. The spacer 200 is an insulating or thermal insulating plate that is arranged in the positive or negative Y-axis direction of the energy storage element 100 and provides insulation and / or thermal insulation between the energy storage elements 100 and each other, or between the energy storage element 100 and the shim 300 or the case 400. The spacer 200 has walls on both sides of the energy storage element 100 in the X-axis direction and on both sides of the energy storage element 100 in the Z-axis direction, thereby functioning as a holder that holds the energy storage element 100 and positions the energy storage element 100. The spacer 200 has flow paths through which a refrigerant (a fluid such as air) flows, and also functions to cool the energy storage element 100.

[0030] The spacer 200 is formed from an insulating material such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyethersulfone (PES), polyamide (PA), ABS resin, or a composite material thereof, or a material having heat insulating properties such as mica.

[0031] 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. Figure 2 shows a configuration in which two storage elements 100, two spacers 200a, and one spacer 200b are arranged alternately, but the other spacers 200a and 200b are also arranged alternately with the storage elements 100 in a similar manner.

[0032] Specifically, as shown in FIG. 2 , the spacer 200a is an intermediate spacer (intermediate holder, middle holder) that has wall portions on both sides in the X-axis direction and on both sides in the Z-axis direction of two energy storage elements 100 arranged on both sides of the spacer 200a in the Y-axis direction and that holds the two energy storage elements 100. The spacer 200b is an end spacer (end holder) that has wall portions on both sides in the X-axis direction and on both sides in the Z-axis direction of one energy storage element 100 arranged on one side of the spacer 200b in the Y-axis direction and that holds the one energy storage element 100. In other words, the energy storage element 100 located at the end of the energy storage unit 10 in the Y-axis direction is held by the spacer 200a and the spacer 200b. The other energy storage elements 100 are held by the two spacers 200a. In this way, the spacer 200a has a double-sided support configuration that supports two energy storage elements 100 on both sides in the Y-axis direction, while the spacer 200b has a single-sided support configuration that supports one energy storage element 100 on only one side in the Y-axis direction. The spacer 200a may 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.

[0033] 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).

[0034] 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 (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 changed as appropriate depending on the amount of compression of the energy storage unit 10 in the Y-axis direction when the energy storage unit 10 is compressed at a constant pressure in the Y-axis direction.

[0035] 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 disposed 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 formed from 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 aluminum die-casting (aluminum die-casting). The case 400 may be formed from an insulating member such as any resin material that can be used for the spacer 200 included in the energy storage unit 10.

[0036] 1 , the case 400 includes a case main body 410 that forms the main body of the case 400, and a lid body 420 that forms the lid body of the case 400. The case main body 410 is a housing (enclosure) with an opening 410a formed in the positive direction of the Z axis, and houses the energy storage unit 10 and the shim 300. The bottom portion (bottom wall portion) of the case main body 410 located at the end in the negative direction of the Z axis is referred to as a bottom portion 411, and the side portion (side wall portion) of the case main body 410 located at the end in the negative direction of the Y axis is referred to as a side portion 412.

[0037] The bottom 411 is a portion of the case 400 (case body 410) that is arranged in the negative Z-axis direction (one side in the second direction). The bottom 411 is a portion of the case 400 (case body 410) that is arranged on one side in the Z-axis direction (second direction) that intersects with the Y-axis direction (first direction) in which the power storage units 10 and the shims 300 are arranged. The bottom 411 is a portion that is arranged in the negative Z-axis direction relative to the power storage units 10 and the shims 300 and has a substantially rectangular parallelepiped shape that is longer in the Y-axis direction. The bottom 411 is arranged in the negative Z-axis direction of the power storage unit 10 so as to cover the entire surface of the power storage unit 10 in the negative Z-axis direction, and supports the power storage unit 10 from the negative Z-axis direction. The bottom 411 is arranged adjacent to the side portion 412.

[0038] The side portion 412 is a portion of the case 400 (case main body 410) that is arranged 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 arranged with its main surface (the surface with the largest area) facing the Y-axis direction, and is a flat, rectangular wall portion parallel to the XZ plane that forms the 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 arranged opposite the shim 300 in the Y-axis direction.

[0039] 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 opposite the bottom 411 of the case body 410. The opening 410a is large enough to allow the energy storage unit 10 and the shim 300 to pass through in the Z-axis direction. After the energy 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 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 (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.

[0040] Next, the configurations of the energy storage device 100, the spacer 200 (particularly the spacer 200b), and the shim 300 will be described in detail.

[0041] [1.1 Description of Energy Storage Element 100] Fig. 3 is a perspective view showing the configuration of the energy storage element 100 according to this embodiment. Fig. 3 shows an enlarged view of the energy storage element 100 shown in Fig. 2. Since the multiple energy storage elements 100 included in the energy storage unit 10 all have the same configuration, Fig. 3 shows one energy storage element 100, and the configuration of one energy storage element 100 will be described in detail below.

[0042] As shown in FIG. 3 , the energy storage element 100 includes a container 110 and a pair of terminals 140 (positive and negative electrodes). The container 110 contains an electrode assembly, a pair of current collectors (positive and negative electrodes), and an electrolyte (non-aqueous electrolyte). Gaskets are disposed between the terminals 140 and current collectors and the container 110, but these are not shown (the 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.

[0043] The container 110 is a rectangular parallelepiped (square or box-shaped) case including a container body 120 with an opening formed therein and a container lid 130 that closes the opening of the container body 120. The container body 120 is a rectangular cylindrical member with a bottom that constitutes the main body of the container 110, and has an opening formed on the positive side of the Z axis. The container lid 130 is a rectangular plate-like member that is elongated in the X axis direction and constitutes the lid of the container 110, and is disposed in the positive direction of the Z axis of the container body 120. The container lid 130 is provided with a gas exhaust valve 131 that releases pressure inside the container 110 if the pressure inside the container 110 increases excessively, a liquid injection portion (not shown) for injecting electrolyte into the container 110, and other components. The material of the container 110 (the container body 120 and the container lid 130) is not particularly limited and can be a weldable (joinable) metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel sheet, but resin can also be used.

[0044] 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 walls 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 surface 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.

[0045] The terminals 140 are electrode terminals (positive and negative terminals) of the energy storage element 100 that are arranged on the container lid 130. The terminals 140 are arranged to protrude from the upper surface (terminal arrangement surface) of the container lid 130 in the positive direction of the Z axis. The terminals 140 are electrically connected to the positive and negative electrode plates of the electrode body via current collectors. The terminals 140 are metal members that conduct electricity stored in the electrode body 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 body. The terminals 140 are formed from aluminum, an aluminum alloy, copper, a copper alloy, or the like.

[0046] 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.

[0047] The current collectors are conductive current collecting members (positive and negative current collectors) electrically and mechanically connected to the terminal 140 and the electrode body. The positive current collector is made of aluminum, an aluminum alloy, or the like, similar to the positive current collector foil of the positive electrode plate of the electrode body, and the negative current collector is made of copper, a copper alloy, or the like, similar to the negative current collector foil of the negative electrode plate of the electrode body.

[0048] [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 in the negative Y-axis direction of energy storage unit 10 shown in Fig. 2. Since the two spacers 200b located at both ends in the Y-axis direction of energy storage unit 10 have the same configuration, only the spacer 200b located at the end in the negative Y-axis direction will be illustrated below, and the configuration of spacer 200b will be described in detail.

[0049] 4, the spacer 200b has a shape that is symmetrical with respect to a plane that passes through the center and is parallel to the YZ plane. The spacer 200b includes a spacer body 210, a spacer wall 220, a spacer protrusion 230, and a pair of legs 240. The spacer body 200b has a shape that is symmetrical with respect to a plane that passes through the center and is parallel to the YZ plane. The spacer 200b includes a spacer body 210, a spacer wall 220, a spacer protrusion 230, and a pair of legs 240.

[0050] 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, which 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 of the container 110 of the energy storage element 100 in the Y-axis direction, so as to cover the entire surface of the long side surface 111 that faces the spacer main body 210, and is disposed 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) that flows between the spacer main body 210 and the energy storage element 100.

[0051] The spacer wall portions 220 are walls arranged on both sides in the Z-axis direction and both sides in the X-axis direction of the energy storage device 100. The spacer wall portions 220 include spacer wall portions 221 (see FIG. 6A ) arranged on both sides in the Z-axis direction at both ends in the X-axis direction of the energy storage device 100, and spacer wall portions 222 arranged on both sides in the X-axis direction at both ends in the Z-axis direction of the energy storage device 100. The spacer wall portions 221 are flat plate-shaped portions parallel to the XY plane that protrude in the positive Y-axis direction from both Z-axis direction end edges at both ends in the X-axis direction of the spacer main body portion 210, 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 that protrude in the positive Y-axis direction from both X-axis direction end edges at both ends in the Z-axis direction of the spacer main body portion 210, 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 element 100. In this way, the spacer 200b holds the energy storage element 100.

[0052] The spacer protrusion 230 is a protrusion that protrudes from the spacer main body 210 in the negative Y-axis direction. 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 Y-axis direction 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 X-axis direction to the spacer protrusion 230 at the end in the negative X-axis direction.

[0053] 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 in the negative Y-axis direction and are long in the Z-axis direction. During manufacturing of 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 the energy storage unit 10 is inserted into the case 400 (case main body 410) in a state in which 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.

[0054] The pair of legs 240 are protrusions (convex portions) that protrude in the negative Z-axis direction from both ends of the spacer main body 210 in the negative Z-axis direction in the X-axis direction 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.

[0055] [1.3 Description of Shim 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. 5A is a perspective view showing the configuration of the shim 300 according to this embodiment. FIG. 5A shows an enlarged view of the shim 300 shown in FIG. 2. FIG. 5B is a cross-sectional view showing the configuration of a shim end portion 330 of the shim 300 according to this embodiment. FIG. 5B shows a cross-section of the shim end portion 330 of the shim 300 shown in FIG. 5A taken along a plane that includes line VB-VB passing through the center position in the X-axis direction and is parallel to the YZ plane. FIG. 6A 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). 6A 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 a VIA-VIA line passing through the center position in the X-axis direction and is parallel to the YZ plane. FIG. 6B is a cross section showing the shim end portion 330 of the shim 300 and the surrounding configuration according to this embodiment. FIG. 6B shows an enlarged view of the shim end portion 330 of the shim 300 and the surrounding configuration shown in FIG. 6A.

[0056] As shown in FIG. 5A , the shim 300 includes a shim body 310 , a shim protruding portion 320 , and a shim end portion 330 .

[0057] [1.3.1 Description of Shim Main 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. 6A , 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 substantially 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 direction of the Y axis of the side portion 412 of the case main body 410, facing 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 protrusion 230 of the spacer 200b and the side portion 412 of the case main body 410, sandwiched between the spacer protrusion 230 and the side portion 412.

[0058] [1.3.2 Description 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 of 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. In other words, 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. 6A , 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. In other words, 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). The shim protrusion 320 is used as a portion to be grasped by a manufacturing device for the energy storage device 1 when the shim 300 is transported during the manufacture of the energy storage device 1 .

[0059] [1.3.3 Description of Shim End 330] The shim end 330 is a portion of the shim main body 310 located in the negative Z-axis direction (one side in the second direction). The shim end 330 is a portion extending in the X-axis direction and located at the end of the shim 300 in the negative Z-axis direction. The shim end 330 is continuously disposed over the entire length of the shim main body 310 in the X-axis direction. As shown in FIGS. 6A and 6B , the shim end 330 does not contact the energy storage unit 10. In other words, the shim end 330 refers to the portion of the end of the shim 300 in the negative Z-axis direction that does not contact the energy storage unit 10. Specifically, the shim end 330 is disposed in a position that does not face the spacer protrusion 230 in the Y-axis direction, and is therefore disposed without contacting the spacer protrusion 230. The shim end 330 is disposed to protrude from the spacer protrusion 230 in the negative Z-axis direction. The shim end 330 is disposed in the positive Y-axis direction of the side portion 412 of the case body 410 , facing the side portion 412 in the Y-axis direction, and in contact with the side portion 412 .

[0060] As shown in FIG. 5B , when the shim end 330 is cut along a plane parallel to the XZ plane including the center of the Y axis, the portion in the positive Y-axis direction is referred to as the first shim end 331, and the portion in the negative Y-axis direction is referred to as the second shim end 332. That is, the shim end 330 includes the first shim end 331 and the second shim end 332, which is disposed in the negative Y-axis direction (one side in the first direction) of the first shim end 331. The first shim end 331 is positioned (protrudes) further in the negative Z-axis direction (one side in the second direction) than the second shim end 332. Specifically, the shim end 330 includes an inclined surface 330a that slopes toward the positive Z-axis direction (the other side in the second direction) as it approaches the negative Y-axis direction (one side in the first direction), thereby forming the first shim end 331 and the second shim end 332. In this embodiment, the inclined surface 330a is a curved surface (a curved surface protruding in the negative Z-axis direction) that curves more in the positive Z-axis direction as it approaches the negative Y-axis direction. As a result, the thickness of the shim end 330 in the Y-axis direction decreases as it approaches the negative Z-axis direction. The shim end 330 is not double-edged, but has a single-edged shape.

[0061] As shown in FIGS. 6A and 6B , a portion of the bottom 411 of the case body 410 that faces the shim end 330 in the Z-axis direction is referred to as the case end 411c. Specifically, the bottom 411 includes a bottom wall 411a and a step portion 411b, and the step portion 411b includes the case end 411c. The bottom wall 411a is the bottom wall of the case 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 that is parallel to the XY plane and elongated in the Y-axis direction, 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 direction of the Y axis, and is disposed in the negative direction of the Z axis of the shim 300. The bottom portion 411 may be formed with a space that serves as a flow path for a refrigerant (gas such as air or liquid) that cools the energy storage element 100, and an opening (through-hole) that connects the space with the outside of the case 400.

[0062] The case end 411c is a portion located at the end of the stepped portion 411b in the positive Z-axis direction, and is a connecting portion with the side portion 412 of the bottom portion 411. The case end 411c is a corner of the inner surface of the bottom portion 411 of the case 400 (case main body 410). The case end 411c is an end (an end in the negative Z-axis direction) of the case 400 (case main body 410) on one side in the Z-axis direction (second direction) that intersects with the Y-axis direction (first direction) in which the energy storage units 10 and the shims 300 are arranged.

[0063] When the case end 411c is cut along a plane parallel to the XZ plane including the center in the Y-axis direction, the portion in the positive Y-axis direction is referred to as the first case end 411d, and the portion in the negative Y-axis direction is referred to as the second case end 411e. That is, the case end 411c includes the first case end 411d and the second case end 411e, which is located in the negative Y-axis direction (one side in the first direction) of the first case end 411d. The portion of the case end 411c facing the first shim end 331 in the Z-axis direction is the first case end 411d, and the portion facing the second shim end 332 in the Z-axis direction is the second case end 411e. The first shim end 331 faces the first case end 411d in the Z-axis direction (second direction), and the second shim end 332 faces the second case end 411e in the Z-axis direction (second direction).

[0064] The second case end 411e is located (protrudes) in the positive Z-axis direction (the other side in the second direction) relative to the first case end 411d. Specifically, the case end 411c includes an inclined surface 411f that inclines in the positive Z-axis direction (the other side in the second direction) as it approaches the negative Y-axis direction (one side in the first direction), thereby forming the first case end 411d and the second case end 411e. In this embodiment, the inclined surface 411f is a curved surface (a curved surface that protrudes in the negative Z-axis direction) that curves in the positive Z-axis direction as it approaches the negative Y-axis direction. In other words, a rounded portion (corner radius) is formed in the case end 411c, which is the connection portion of the bottom 411 with the side portion 412.

[0065] In this configuration, as shown in Figures 6A and 6B, the shim end 330 is disposed in contact with the case end 411c in the Z-axis direction. The first shim end 331 contacts the first case end 411d in the Z-axis direction, and the second shim end 332 contacts the second case end 411e in the Z-axis direction. In this embodiment, the inclined surface 330a of the shim end 330 has the same inclination as the inclined surface 411f of the case end 411c, and the entire inclined surface 330a of the shim end 330 contacts the inclined surface 411f of the case end 411c. In other words, the shim 300 is machined so that the inclined surface 330a of the shim end 330 has the same shape as the inclined surface 411f of the case end 411c. The shim 300 is machined into a shape such that a portion of the inclined surface 330a of the shim end 330 does not contact the inclined surface 411f of the case end 411c, and a configuration in which a portion of the inclined surface 330a does not contact the inclined surface 411f is also possible. In this manner, the shim 300 is disposed in contact with the bottom 411 of the case 400 (case main body 410). This positions the shim 300 relative to the case 400 (case main body 410).

[0066] [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 the 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.

[0067] Next, the manufacturing apparatus inserts the power storage unit 10 into the case body 410 while compressing the power storage unit 10 in the Y-axis direction. As a result, the power storage unit 10 is disposed within the case body 410 while being spaced apart from the side portion 412 of the case body 410. In this state, the manufacturing apparatus transports the shim 300 by, for example, air-suctioning the shim 300 or gripping the shim protrusion 320, and inserts the shim 300 between the side portion 412 and the power storage unit 10 within the case body 410. By gripping the shim protrusion 320, the manufacturing apparatus can move the shim 300 further downward and then drop it into the case body 410. As a result, the shim 300 comes into contact with the bottom portion 411 of the case body 410 and is positioned relative to the case body 410. The power storage unit 10 may be inserted into the case body 410 after the shim 300 is disposed within the case body 410.

[0068] 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 portions of the spacers 200 return to their original state, and the energy storage unit 10 expands in the Y-axis direction, with the shim 300 sandwiched between the side portions 412 and the energy storage unit 10. Thereafter, the manufacturing equipment is removed, resulting in the state shown in FIG. 6A .

[0069] 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.

[0070] [3 Description of Effects] As described above, according to the energy storage device 1 of this embodiment, in the case 400, the second case end 411e is located (protrudes) in the positive Z-axis direction (the other side in the second direction) relative to the first case end 411d. In the shim 300, the first shim end 331 facing the first case end 411d is located (protrudes) in the negative Z-axis direction (one side in the second direction) relative to the second shim end 332 facing the second case end 411e. In this way, the positional relationship (protruding relationship) between the first shim end 331 and the second shim end 332 of the shim 300 in the Z-axis direction (second direction) corresponds to the positional relationship (protruding relationship) between the first case end 411d and the second case end 411e of the case 400. In other words, even if a portion of the case end 411c is located (protrudes) relative to other portions in the Z-axis direction (second direction), the shim end 330 is shaped to correspond to the case end 411c in the Z-axis direction (second direction). This prevents the shim 300 from being disposed in an inclined state even when the shim end 330 comes into contact with the case end 411c, thereby preventing misalignment of the shim 300. This prevents problems such as scraping of the case 400 or deterioration of vibration resistance caused by the shim 300.

[0071] The case end 411c has an inclined surface 411f that inclines in the positive Z-axis direction (the other side in the second direction) as it approaches the negative Y-axis direction (one side in the first direction), and the shim end 330 has an inclined surface 330a that inclines in the positive Z-axis direction (the other side in the second direction) as it approaches the negative Y-axis direction (one side in the first direction). In this way, even when the inclined surface 411f is formed on the case end 411c, the shim end 330 has an inclined surface 330a that inclines in the same direction as the inclined surface 411f of the case end 411c. This prevents the shim 300 from being disposed in an inclined state even when the shim end 330 comes into contact with the case end 411c.

[0072] Case end 411c is a connecting portion of bottom 411 of case 400 with side portion 412. In other words, case end 411c has a rounded portion (corner radius) formed at a corner of bottom 411 of case 400. In this way, even if bottom 411 of case 400 has a rounded portion, it is possible to prevent shim end 330 from coming into contact with the rounded portion and causing shim 300 to be positioned in an inclined state.

[0073] In the shim 300, the shim main body 310 contacts the power storage unit 10, while the shim end 330 does not contact the power storage unit 10. In other words, by arranging the shim main body 310 at a position in the shim 300 where it contacts the power storage unit 10, the flat shim main body 310 receives the load from the power storage unit 10. Because the shim end 330 may not be able to receive the load from the power storage unit 10, the shim end 330 is arranged at a position where it does not contact the power storage unit 10. In this way, by separating the portion of the shim 300 that receives the load (the shim main body 310) from the portion that suppresses misalignment (the shim end 330), it is possible to suppress the influence on the load (constant pressure load) received by the shim 300.

[0074] [4 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.

[0075] (Variation 1) In the above embodiment, a portion may be provided that limits the movement of shim end portion 330 of shim 300. Fig. 7 is a cross-sectional view showing the shim end portion 330 of shim 300 and the surrounding configuration according to Variation 1 of this embodiment. Fig. 7 is a view corresponding to Fig. 6B.

[0076] As shown in FIG. 7 , the bottom portion 411 in this modification includes a protrusion 411g in addition to the configuration of the bottom portion 411 in the above-described embodiment. The protrusion 411g is a protrusion (projection) disposed in the positive Y-axis direction (the other side in the first direction) of the shim end portion 330 and protruding in the positive Z-axis direction (the other side in the second direction). This restricts movement of the shim end portion 330 in the positive Y-axis direction. The protrusion 411g is disposed in a position within the space between the shim 300 and the spacer 200b where it does not come into contact with other components, such as the spacer 200b. In this modification, the protrusion 411g is disposed at the end of the step portion 411b in the positive Y-axis direction. The shape of the protrusion 411g is not particularly limited and may be any shape, such as a circle, an ellipse, an oval, a rectangle, or any other polygonal shape, as viewed in the Z-axis direction. The protrusion 411g may extend in the X-axis direction, or multiple protrusions 411g may be arranged side by side in the X-axis direction. The other configurations of this modification are the same as those of the above embodiment, and therefore description thereof will be omitted.

[0077] This modification can also achieve the same effects as the above-described embodiment. In this modification, the bottom 411 of the case 400 has a protrusion 411g in the positive Y-axis direction (the other side in the first direction) of the shim end 330, and the protrusion 411g can restrict movement of the shim end 330 in the positive Y-axis direction (the other side in the first direction). Even when the shim 300 is placed inside the case body 410 and then the energy storage unit 10 is inserted into the case body 410, the protrusion 411g can position the shim 300. This can prevent the shim 300 from being placed in an inclined state.

[0078] (Modification 2) In the above embodiment, the inclined surface 330a of the shim end 330 of the shim 300 is a curved surface, but it may be a flat inclined surface. Figure 8 is a cross-sectional view showing the shim end 333 of the shim 301 according to Modification 2 of this embodiment and the surrounding configuration. Figure 8 is a view corresponding to Figure 6B.

[0079] As shown in FIG. 8 , the shim end 333 of the shim 301 in this modification includes a first shim end 331a and a second shim end 332a instead of the first shim end 331 and the second shim end 332 included in the shim end 330 of the shim 300 in the above embodiment. The first shim end 331a is located (protrudes) in the negative Z-axis direction (one side in the second direction) relative to the second shim end 332a, but the surface facing the negative Z-axis direction is flat. Specifically, the shim end 333 includes a flat inclined surface 330b that slopes in the positive Z-axis direction (the other side in the second direction) as it approaches the negative Y-axis direction (one side in the first direction), thereby forming the first shim end 331a and the second shim end 332a. In this modification, the first shim end 331a is positioned in contact with the case end 411c (first case end 411d) in the Z-axis direction. The other configurations of this modified example are the same as those of the above embodiment, and therefore description thereof will be omitted.

[0080] This modification can also achieve the same effects as the above embodiment. In this modification, the inclined surface 330b of the shim end portion 333 is a flat inclined surface, so that the shim 301 can be easily processed.

[0081] (Modification 3) In the above embodiment, the shim end 330 of the shim 300 has an inclined surface 330a, but this is not limited to this. Fig. 9 is a cross-sectional view showing the shim end 334 of the shim 302 according to Modification 3 of this embodiment and the surrounding configuration. Fig. 9 is a view corresponding to Fig. 6B.

[0082] As shown in FIG. 9 , the shim end portion 334 of the shim 302 in this modification includes a first shim end portion 331b and a second shim end portion 332b instead of the first shim end portion 331 and the second shim end portion 332 of the shim end portion 330 of the shim 300 in the above embodiment. The first shim end portion 331b is positioned (protrudes) in the negative Z-axis direction (one side in the second direction) relative to the second shim end portion 332b, but its surface in the negative Z-axis direction is not inclined. Specifically, the shim end portion 334 includes a stepped (step-like) step surface 330c, thereby forming the first shim end portion 331b and the second shim end portion 332b. In this modification, the first shim end portion 331b is positioned in contact with the case end portion 411c (first case end portion 411d) in the Z-axis direction. The remaining configuration of this modification is similar to that of the above embodiment, and therefore will not be described further.

[0083] This modification can also achieve the same effects as the above-described embodiment. In this modification, the shim end portion 334 is provided with the step surface 330c, which makes it easy to process the shim 302.

[0084] (Variation 4) In the above embodiment, the inclined surface 330a of the shim end 330 of the shim 300 and the inclined surface 411f of the case end 411c of the bottom 411 of the case main body 410 are in contact with each other, but this is not limiting. Fig. 10 is a cross-sectional view showing the shim end 335 of the shim 303 and the surrounding structure according to Variation 4 of this embodiment. Fig. 10 is a view corresponding to Fig. 6B.

[0085] As shown in FIG. 10 , the case end 411c of the bottom 411 of the case body 410 in this modification includes a first case end 411h and a second case end 411i instead of the first case end 411d and second case end 411e of the case end 411c in the above embodiment. The second case end 411i is located (protrudes) in the positive Z-axis direction (the other side of the second direction) relative to the first case end 411h, but its surface in the positive Z-axis direction is not inclined. Specifically, the case end 411c in this modification includes a stepped (step-like) step surface 411j, thereby forming the first case end 411h and the second case end 411i. Similarly to the third modification, the shim end 335 of the shim 303 in this modification includes a stepped (step-like) step surface 330d, thereby forming the first shim end 331c and the second shim end 332c. The step surface 330d of the shim end 335 is disposed in contact with the step surface 411j of the case end 411c in the Z-axis direction. The other configurations of this modified example are the same as those of the above embodiment, and therefore will not be described.

[0086] This modification can also achieve the same effects as the above-described embodiment. In this modification, the shim 303 can be easily positioned relative to the case 400 (case body 410) by bringing the step surface 330d of the shim end 335 into contact with the step surface 411j of the case end 411c. In this modification, the entire surface of the step surface 330d is in contact with the step surface 411j, but a configuration in which a portion of the step surface 330d does not contact the step surface 411j is also possible.

[0087] (Variation 5) In the above embodiment, the shim end 330 of the shim 300 is arranged continuously over the entire length of the shim main body 310 in the X-axis direction, but this is not limited to this. The shim end 330 may include multiple portions arranged intermittently over the entire length of the shim main body 310 in the X-axis direction. The shim end 330 may be arranged only over a portion of the shim main body 310 in the X-axis direction, rather than over the entire length. An example of this case will be described below. Figure 11 is a front view showing the configuration of a shim 304 according to Variation 5 of this embodiment. Figure 11 is a view from the Y-axis direction of a configuration in which two shims 304 are arranged side by side in the Z-axis direction.

[0088] 11 , the shim 304 in this modification has a shim end portion 336 that is shorter in the X-axis direction than the shim end portion 330 of the shim 300 in the above embodiment. The shim end portion 336 is disposed between the two shim protrusions 320 in the X-axis direction (third direction). In other words, the length of the shim end portion 336 in the X-axis direction is shorter than the distance between the two shim protrusions 320, and the shim end portion 336 is disposed between the two shim protrusions 320 when viewed in the Z-axis direction. The other configurations of this modification are the same as those of the above embodiment, and therefore will not be described again.

[0089] This modification can also achieve the same effects as the above-described embodiment. In this modification, the shim end 336 is disposed in the X-axis direction (third direction) between two shim protrusions 320 of the shim 304 that protrude in the positive Z-axis direction (the other side in the second direction). That is, the shim 304 has two shim protrusions 320 that protrude in the positive Z-axis direction (the other side in the second direction) from the shim main body 310 and are aligned in the X-axis direction (third direction) for use during transportation, etc. Therefore, the shim end 336 is disposed between the two shim protrusions 320 in the X-axis direction (third direction). With this configuration, when two shims 304 are aligned in the Z-axis direction (second direction), as shown in FIG. 11 , the shim end 336 of one shim 304 positioned in the positive Z-axis direction (the other side in the second direction) can be disposed between the two shim protrusions 320 of the other shim 304 positioned in the negative Z-axis direction (one side in the second direction). As a result, when multiple shims 304 are continuously produced in the Z-axis direction (second direction) by punching or the like, the shim end portion 336 of one shim 304 can be arranged between the two shim protrusions 320 of the other shim 304. Therefore, the material between the two shim protrusions 320 of one shim 304 can be used for the shim end portion 336 of the other shim 304, thereby reducing the amount of material used.

[0090] (Other Modifications) In the above embodiment, the shim end 330 is the end of the shim 300 in the negative Z-axis direction, and the case end 411c is the end of the case 400 in the negative Z-axis direction, but this is not limited to this. The shim end 330 may be the end of the shim 300 in the X-axis direction, and the case end 411c may be the end of the case 400 in the X-axis direction. Even in this case, it is possible to suppress misalignment of the shim 300 with respect to the case 400 at the end of the case 400 in the X-axis direction.

[0091] In the above embodiment, the half of the shim end 330 in the positive Y-axis direction is the first shim end 331, and the half in the negative Y-axis direction is the second shim end 332. However, this is not limited to this. The first shim end 331 and the second shim end 332 may be portions of the shim end 330 divided at any ratio. The first shim end 331 and the second shim end 332 may be formed by dividing not all of the shim end 330 but a portion of it. In other words, as long as the second shim end 332 is positioned in the negative Y-axis direction of the first shim end 331, any portion of the shim end 330 may be formed as the first shim end 331 and the second shim end 332. The same applies to the first case end 411d and the second case end 411e of the case end 411c.

[0092] In the above embodiment, the shim end portion 330 is not in contact with the energy storage unit 10 (spacer 200b), but at least a part of the shim end portion 330 may be in contact with the energy storage unit 10 (spacer 200b).

[0093] In the above embodiment, the shim end 330 is arranged in contact with the case end 411c, but the shim end 330 may be arranged spaced apart from the case end 411c.

[0094] In the above embodiment, the bottom 411 of the case 400 has the step 411b, but it does not have to have the step 411b. In this case, the case end 411c may be the connection portion between the bottom wall 411a and the side portion 412.

[0095] In the above embodiment, the case end 411c is a portion of the bottom 411 that is connected to the side 412, but this is not limiting. The case end 411c may be a portion of the bottom 411 that is separated from the side 412.

[0096] In the above embodiment, the spacer wall 220 of the spacer 200b has a plurality of walls, but this is not limited thereto. The spacer 200b may be a holder that holds the energy storage element 100 by including at least one of the plurality of walls included in the spacer wall 220, or may be a spacer that does not hold the energy storage element 100 by not including all of the walls.

[0097] 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.

[0098] 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, to accommodate a portion of the power storage unit 10 in the positive direction of the Z-axis.

[0099] In the above embodiment, a plurality of power storage units 10 aligned in the X-axis direction may be housed inside the case 400. A plurality of power storage units 10 aligned 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.

[0100] In the above embodiment, the case 400 includes the case body 410 and the lid 420, but the lid 420 may not be included.

[0101] In the above embodiment, the energy storage unit 10 may not include the spacer 200a or the spacer 200b.

[0102] Any combination of the components of the above-described embodiment and its modifications is also included within the scope of the present invention.

[0103] The present invention can be applied to an electricity storage device including an electricity storage element such as a lithium ion secondary battery.

[0104] REFERENCE SIGNS LIST 1 Energy storage device 10 Energy storage unit 100 Energy storage element 110 Container 140 Terminal 200, 200a, 200b Spacer 210 Spacer main body 220, 221, 222 Spacer wall 230, 231, 232, 233, 234, 235 Spacer protrusion 300, 301, 302, 303, 304 Shim 310 Shim main body 320 Shim protrusion 330, 333, 334, 335, 336 Shim end 330a, 330b, 411f Inclined surface 330c, 330d, 411j Step surface 331, 331a, 331b, 331c First shim end 332, 332a, 332b, 332c Second shim end 400 Case 410 Case body 411 Bottom 411a Bottom wall 411b Stepped portion 411c Case end 411d, 411h First case end 411e, 411i Second case end 411g Convex portion 412 Side 420 Lid

Claims

1. An energy storage device comprising: a power storage unit having a power storage element; a shim arranged adjacent to the power storage unit; and a case accommodating the power storage unit and the shim, wherein the case has a case end which is an end on one side in a second direction which is a direction intersecting a first direction in which the power storage unit and the shim are arranged; the shim has: a flat shim main body portion; and a shim end which is arranged on the one side in the second direction of the shim main body portion and faces the case end in the second direction, wherein the case end comprises a first case end and a second case end which is arranged on the one side of the first case end in the first direction, wherein the second case end is located on the other side in the second direction than the first case end, and wherein the shim end comprises a first shim end which faces the first case end in the second direction and a second shim end which faces the second case end in the second direction, wherein the first shim end is located on the one side in the second direction than the second shim end.

2. The energy storage device of claim 1, wherein the case end has an inclined surface that slopes toward the other side in the second direction as it approaches the one side in the first direction, thereby forming the first case end and the second case end, and the shim end has an inclined surface that slopes toward the other side in the second direction as it approaches the one side in the first direction, thereby forming the first shim end and the second shim end.

3. A storage device as described in claim 1 or 2, wherein the case has a side portion arranged on one side in the first direction and a bottom portion arranged on one side in the second direction, and the case end portion is a connection portion of the bottom portion with the side portion.

4. The electricity storage device according to claim 3, wherein the bottom portion is disposed on the other side of the shim end portion in the first direction and includes a protrusion that protrudes toward the other side in the second direction.

5. The electricity storage device according to claim 1 or 2, wherein the shim body portion is in contact with the electricity storage unit, and the shim end portion is not in contact with the electricity storage unit.

6. The energy storage device according to claim 1 or 2, wherein the shim has two protruding portions that protrude from the shim main body portion to the other side of the second direction and are aligned in a third direction that intersects the first direction and the second direction, and the shim end portion is positioned between the two protruding portions in the third direction.

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