Energy storage device

Abstract

To provide a power storage device that can improve ease of assembly.SOLUTION: A power storage device 1 includes a power storage element 100, and a first spacer 201 and a second spacer 202 sandwiching the power storage element 100 in the first direction. The first spacer 201 protrudes to one side in the first direction, and has a first spacer wall portion 220 disposed opposite to the power storage element 100 in a second direction intersecting the first direction. The second spacer 202 has a second spacer wall portion 230 that protrudes to the other side in the first direction and is disposed opposite to the first spacer wall portion 220 in the second direction. The second spacer wall portion 230 is arranged in a deformed state toward the first spacer wall portion 220.SELECTED DRAWING: Figure 8

Description

Technical Field

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[0001] The present invention relates to a power storage device including a power storage element and a pair of spacers sandwiching the power storage element.

Background Art

[0002] Conventionally, a power storage device including a power storage element and a pair of spacers sandwiching the power storage element has been widely known. For example, Patent Document 1 discloses a battery pack (power storage device) including a plurality of secondary batteries (power storage elements) and a plurality of separators (spacers) sandwiching the secondary batteries. In this battery pack (power storage device), a first wall of one of the plurality of separators (spacers) and a second wall of the separator adjacent to the one separator are arranged so as to overlap each other in the width direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a power storage device having the above conventional configuration, it may be difficult to arrange a pair of spacers sandwiching the power storage element. In the power storage device disclosed in Patent Document 1, since a pair of spacers sandwiching the power storage element are arranged such that the first wall and the second wall overlap each other in the width direction, the first wall and the second wall may come into contact with each other when arranging the pair of spacers, and it may be difficult to arrange the pair of spacers. As a result, the assemblability of the power storage device may deteriorate.

[0005] The present invention has been made by the inventors of the present application newly paying attention to the above problems, and an object thereof is to provide a power storage device capable of improving assemblability.

Means for Solving the Problems

[0006] An energy storage device according to one aspect of the present invention comprises an energy storage element and a first spacer and a second spacer that sandwich the energy storage element in a first direction, wherein the first spacer has a first spacer wall portion that protrudes to one side of the first direction and is positioned opposite to the energy storage element in a second direction intersecting the first direction, and the second spacer has a second spacer wall portion that protrudes to the other side of the first direction and is positioned opposite to the first spacer wall portion in the second direction, wherein the second spacer wall portion is positioned in a deformed state toward the first spacer wall portion. [Effects of the Invention]

[0007] The energy storage device according to the present invention can improve ease of assembly. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing the configuration of the energy storage device according to the embodiment. [Figure 2] This is an exploded perspective view showing the energy storage element and spacer of the energy storage unit included in the energy storage device according to the embodiment. [Figure 3] This is a perspective view showing the configuration of the energy storage element according to the embodiment. [Figure 4] These are perspective views and front views showing the configuration of the spacer according to the embodiment. [Figure 5] These are perspective views, rear views, and side views showing the configuration of the spacer according to the embodiment. [Figure 6] This is a perspective view showing the configuration of the first spacer, second spacer, and third spacer according to the embodiment. [Figure 7] This is a cross-sectional view showing the configuration of the first spacer, second spacer, and third spacer according to the embodiment. [Figure 8] This is a cross-sectional view showing the configuration of the first spacer, second spacer, and third spacer according to the embodiment in a deformed state. [Figure 9]This is a cross-sectional view showing an example of the process by which the spacer wall portion of the second spacer according to the embodiment deforms relative to the spacer wall portion of the first spacer. [Figure 10] This is a cross-sectional view showing the configuration of the first spacer, second spacer, and third spacer in a deformed state, according to a modified example of the embodiment. [Modes for carrying out the invention]

[0009] An energy storage device according to one aspect of the present invention comprises an energy storage element and a first spacer and a second spacer that sandwich the energy storage element in a first direction, wherein the first spacer has a first spacer wall portion that protrudes to one side of the first direction and is positioned opposite to the energy storage element in a second direction intersecting the first direction, and the second spacer has a second spacer wall portion that protrudes to the other side of the first direction and is positioned opposite to the first spacer wall portion in the second direction, wherein the second spacer wall portion is positioned in a deformed state toward the first spacer wall portion.

[0010] According to this, the energy storage device comprises a first spacer and a second spacer that sandwich the energy storage element. The second spacer has a second spacer wall portion that faces the first spacer wall portion of the first spacer, and the second spacer wall portion is positioned in a deformed state toward the first spacer wall portion. In other words, the first and second spacers are positioned with the second spacer wall portion separated from the first spacer wall portion, and after the first and second spacers are positioned, the second spacer wall portion is deformed toward the first spacer wall portion. In this way, the first and second spacers can be positioned with the second spacer wall portion separated from the first spacer wall portion, so that contact between the first spacer wall portion and the second spacer wall portion can be suppressed when positioning the first and second spacers. As a result, the first and second spacers can be easily positioned, improving the ease of assembly of the energy storage device.

[0011] The second spacer wall may have a projection that protrudes in a direction away from the first spacer wall.

[0012] According to this, since the second spacer wall portion of the second spacer has a protruding portion that protrudes in a direction away from the first spacer wall portion of the first spacer, by pushing the protruding portion, the second spacer wall portion can be easily deformed toward the first spacer wall portion. Thereby, the second spacer wall portion can be easily arranged in a deformed state toward the first spacer wall portion.

[0013] The protruding portion may have an inclined surface inclined in the second direction on an end surface in the second direction.

[0014] According to this, since an inclined surface is formed on the end surface of the protruding portion of the second spacer wall portion of the second spacer, by pushing the inclined surface, the second spacer wall portion can be deformed. Thereby, even when it is difficult to push the protruding portion from the second direction, by pushing the inclined surface, the second spacer wall portion can be easily deformed toward the first spacer wall portion.

[0015] One of the first spacer wall portion and the second spacer wall portion may have a convex portion that protrudes in the second direction toward the other, and the other may have an opening into which the convex portion is inserted.

[0016] According to this, since one convex portion of the first spacer wall portion and the second spacer wall portion is inserted into the other opening, the first spacer wall portion and the second spacer wall portion can be positioned relative to each other. Thereby, since the first spacer and the second spacer can be positioned relative to each other, the first spacer and the second spacer can be easily arranged.

[0017] The convex portion or the opening provided in the second spacer wall portion may be arranged at a position closer to the tip than the base of the second spacer wall portion in the first direction.

[0018] According to this, since the convex portion or the opening is formed near the tip of the second spacer wall portion, the convex portion can be arranged away from the opening before the deformation of the second spacer wall portion, so that it is possible to suppress the convex portion from contacting the opening or its vicinity. Thereby, when arranging the first spacer and the second spacer, it is possible to suppress the first spacer wall portion and the second spacer wall portion from contacting each other.

[0019] Hereinafter, a power storage device according to an embodiment (including its modification) of the present invention will be described with reference to the drawings. The embodiments described below are all illustrative of comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, manufacturing processes, order of manufacturing processes, etc. shown in the following embodiments are merely examples and are not intended to limit the present invention. In each figure, dimensions and the like are not precisely illustrated. In each figure, the same or similar components are denoted by the same reference numerals.

[0020] In the following description and drawings, the arrangement direction of a pair of electrode terminals of the power storage element, the opposing direction of a pair of short side surfaces in the container of the power storage element, or the arrangement direction of the power storage units is defined as the X-axis direction. The opposing direction of a pair of long side surfaces in the container of the power storage element, the thickness direction (flat direction) of the container of the power storage element, the arrangement direction of a plurality of power storage elements of the power storage unit, or the arrangement direction of the power storage element and the spacer of the power storage unit is defined as the Y-axis direction. The protruding direction of the electrode terminal of the power storage element, the arrangement direction of the container body and the container lid portion of the power storage element, the arrangement direction of the case body and the lid of the case, the opposing direction of the opening and the bottom wall of the case body, or the vertical direction is defined as the Z-axis direction. These X-axis direction, Y-axis direction and Z-axis direction are directions that intersect (orthogonal in this embodiment) with each other. Depending on the usage mode, the Z-axis direction may not be the vertical direction, but hereinafter, for the convenience of explanation, the Z-axis direction will be described as the vertical direction.

[0021] In the following explanation, the X-axis positive direction refers to the direction of the X-axis arrow, and the X-axis negative direction refers to the opposite direction. When simply referring to the X-axis direction, it refers to either the X-axis positive direction or the X-axis negative direction, or one of them. When referring to one side and the other side of the X-axis direction, it refers to one and the other of the X-axis positive direction and the X-axis negative direction. The same applies to the Y-axis direction and the Z-axis direction. Below, the Y-axis direction will also be referred to as the first direction, and the X-axis direction as the second direction. The Y-axis positive direction will also be referred to as one side of the first direction, and the Y-axis negative direction will also be referred to as the other side of the first direction. Expressions indicating relative directions or orientations, such as parallel and orthogonal, include cases where they are not strictly those directions or orientations. For example, two directions being parallel means not only that the two directions are perfectly parallel, but also that they are substantially parallel, i.e., they may include a difference of, for example, a few percent. In the following explanation, when "insulation" is used, it means "electrical insulation".

[0022] (Embodiment) [1. Description of Energy Storage Device 1] First, the general configuration of the energy storage device 1 in this embodiment will be described. Figure 1 is a perspective view showing the configuration of the energy storage device 1 according to this embodiment. In Figure 1, the lid 320 is removed from the case body 310 of the case 300 in the energy storage device 1. As a result, Figure 1 shows two energy storage units 10 arranged inside the case 300. Figure 2 is an exploded perspective view showing the energy storage elements 100 and spacers 200 of the energy storage unit 10 in the energy storage device 1 according to this embodiment. Figure 2 shows the components of the energy storage unit 10 disassembled, illustrating two of the energy storage elements 100 and three spacers 200 (spacers 200a). In Figure 1, the spacers 200a have a portion that protrudes upward, but in Figure 2, for the sake of explanation, the illustration of the portion that protrudes upward of the spacers 200a is omitted. The same applies to Figures 4 and onward.

[0023] The energy storage device 1 is a device that can charge electricity from an external source and discharge electricity to an external source. The energy storage device 1 is used for power storage or power supply purposes. The energy storage device 1 is used as a battery for driving or starting the engine of mobile vehicles such as automobiles, motorcycles, watercraft, ships, snowmobiles, agricultural machinery, construction machinery, or railway vehicles for electric railways. Examples of automobiles include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fossil fuel (gasoline, diesel, liquefied natural gas, etc.) vehicles. Examples of railway vehicles for electric railways include electric trains, monorails, maglev trains, and hybrid trains equipped with both diesel engines and electric motors. The energy storage device 1 can also be used as a stationary battery for household or commercial use.

[0024] As shown in Figure 1, the energy storage device 1 comprises an energy storage unit 10 and a case 300 that houses the energy storage unit 10. The energy storage device 1 also includes external terminals (positive external terminal and negative external terminal) for electrically connecting to external devices, but their illustration and description are omitted. In addition to the above components, the energy storage device 1 may also include a circuit board and electrical equipment such as relays for monitoring or controlling the charging and discharging states of the energy storage unit 10.

[0025] The energy storage unit 10 is a battery module (battery pack) having a plurality of energy storage elements 100. The energy storage unit 10 has a roughly rectangular parallelepiped shape that is long in the Y-axis direction, as the plurality of energy storage elements 100 are arranged alternately with spacers 200 in the Y-axis direction (first direction). In this embodiment, two energy storage units 10 arranged in the X-axis direction are housed inside the case 300. The energy storage unit 10 has a plurality of energy storage elements 100 and a plurality of spacers 200 (200a, 200b, and 200c). The energy storage unit 10 also includes busbars for connecting the energy storage elements 100 in series or parallel, a busbar frame for holding the busbars, and busbars for connecting the energy storage elements 100 to external terminals, but these are not shown in the illustration. The busbars may connect all the energy storage elements 100 in series, or any of the energy storage elements 100 may be connected in parallel and then connected in series, or all the energy storage elements 100 may be connected in parallel.

[0026] The energy storage element 100 is a secondary battery (single cell) capable of charging and discharging electricity, and more specifically, a non-aqueous electrolyte secondary battery such as a lithium-ion secondary battery. The energy storage element 100 has a flattened rectangular parallelepiped shape (square, prism) in the Y-axis direction. In this embodiment, multiple energy storage elements 100 are arranged in line in the Y-axis direction, but the number of energy storage elements 100 arranged is not particularly limited; it may be one, several dozen, or more. The size and shape of the energy storage element 100 are also not particularly limited; it may be an elongated cylindrical shape, an elliptical cylindrical shape, a cylindrical shape, a polygonal prism shape other than a rectangular parallelepiped, etc. The energy storage element 100 is not limited to a non-aqueous electrolyte secondary battery; it may be a secondary battery other than a non-aqueous electrolyte secondary battery, or it may be a capacitor. The energy storage element 100 may not be a secondary battery, but a primary battery that allows the user to use the stored electricity without charging. The energy storage element 100 may be a battery using a solid electrolyte. The energy storage element 100 may be a pouch-type energy storage element.

[0027] The spacer 200 is a flattened member in the Y-axis direction, positioned alongside the energy storage element 100 in the Y-axis direction, and insulating and / or heat-insulating the energy storage element 100 from other members. The spacer 200 is an insulating or heat-insulating plate positioned in the positive or negative Y-axis direction of the energy storage element 100, and insulating and / or heat-insulating the energy storage elements 100 from each other or from the energy storage element 100 to the case 300. The spacer 200 has walls on both the X-axis and Z-axis sides of the energy storage element 100, and thus functions as a holder that holds the energy storage element 100 and positions the energy storage element 100.

[0028] Spacer 200 is formed from insulating materials 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), polyetheretherketone (PEEK), tetrafluoroethylene perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyethersulfone (PES), polyamide (PA), ABS resin, or composite materials thereof, or from insulating materials such as mica.

[0029] Hereinafter, the spacer 200 positioned at the center of the energy storage unit 10 in the Y-axis direction (between the two energy storage elements 100 at the center) will also be referred to as spacer 200b. The spacers 200 positioned at both ends of the energy storage unit 10 in the Y-axis direction (between the end energy storage elements 100 and the case 300) will also be referred to as spacer 200c. The spacer 200 positioned between spacer 200b and spacer 200c (between the two energy storage elements 100 other than the center) will also be referred to as spacer 200a. Spacers 200a, 200b, and 200c are arranged alternately with the energy storage elements 100. Figure 2 shows a configuration in which the energy storage elements 100 and spacer 200a are arranged alternately, but the energy storage elements 100 and spacers 200b and 200c are also arranged alternately in the same manner.

[0030] Specifically, as shown in Figure 2, spacer 200a is an intermediate spacer (intermediate holder) that holds two energy storage elements 100 arranged on both sides of the spacer 200a in the Y-axis direction, with walls on both sides of the X-axis direction and the Z-axis direction of the two energy storage elements 100. Similarly, spacer 200b is a center plate (center spacer or center holder) that holds two energy storage elements 100 arranged on both sides of spacer 200b in the Y-axis direction, with walls on both sides of the X-axis direction and the Z-axis direction of the two energy storage elements 100. Spacer 200b has the function of increasing the rigidity of the energy storage unit 10 which is long in the Y-axis direction. Spacer 200c is an end spacer (end holder) that holds one energy storage element 100 arranged on one side of spacer 200c in the Y-axis direction, with walls on both sides of the X-axis direction and the Z-axis direction of the one energy storage element 100.

[0031] In other words, the energy storage element 100 located in the center of the energy storage unit 10 in the Y-axis direction is held by spacers 200a and 200b. The energy storage element 100 located at the ends of the energy storage unit 10 in the Y-axis direction is held by spacers 200a and 200c. The remaining energy storage elements 100 are held by the two spacers 200a. All spacers 200 (spacers 200a, 200b, and 200c) may be made of the same material, or any of the spacers 200 may be made of a different material.

[0032] The case 300 is a roughly rectangular parallelepiped (box-shaped) container that constitutes the outer casing (shell) of the energy storage device 1. The case 300 is positioned outside the energy storage unit 10, fixing the energy storage unit 10 in a predetermined position and protecting it from impacts, etc. The case 300 is a metal case formed from a metal component such as aluminum, aluminum alloy, stainless steel, iron, or plated steel sheet. In this embodiment, the case 300 is formed from die-cast aluminum (aluminum die-cast). The case 300 may also be formed from an insulating component such as any resin material that can be used for the spacer 200 of the energy storage unit 10.

[0033] As shown in Figure 1, the case 300 comprises a case body 310 that constitutes the main body of the case 300 and a cover 320 that constitutes the cover of the case 300. The case body 310 is a housing with an opening 310a formed in the Z-axis positive direction and houses the energy storage unit 10 (energy storage element 100 and spacers 200 (spacers 200a, 200b, and 200c)). The cover 320 is a flat rectangular member that closes the opening 310a of the case body 310. The case body 310 has two rectangular openings 310a arranged in the X-axis direction, and after the energy storage unit 10 is inserted through each opening 310a, the case body 310 and the cover 320 are joined by bolts, welding, adhesive, etc. This gives the case 300 a sealed structure. The case body 310 or the lid 320 may have a terminal block for external terminals (positive external terminal and negative external terminal) attached to it, and the external terminals may be arranged on the terminal block.

[0034] Next, the configuration of the energy storage element 100 and the spacer 200a will be described in detail.

[0035] [1.1 Description of the energy storage element 100] Figure 3 is a perspective view showing the configuration of the energy storage element 100 according to this embodiment. Figure 3 shows an enlarged view of the energy storage element 100 shown in Figure 2. Since all of the multiple energy storage elements 100 in the energy storage unit 10 have the same configuration, Figure 3 shows one energy storage element 100, and the configuration of this one energy storage element 100 will be described in detail below.

[0036] As shown in Figure 3, the energy storage element 100 has a container 110 and a pair of electrode terminals 140 (positive and negative). Inside the container 110 are the electrode body, the pair of current collectors (positive and negative), and the electrolyte (non-aqueous electrolyte). A gasket is placed between the electrode terminals 140 and the current collectors and the container 110, but these are not shown in the illustration. There are no particular restrictions on the type of electrolyte 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 material as long as it has insulating properties. In addition to the above components, the energy storage element 100 may also have a spacer placed to the side of the electrode body, an insulating film that encloses the electrode body, etc., and an insulating film (shrink tubing, etc.) that covers the outer surface of the container 110.

[0037] The container 110 is a rectangular parallelepiped (square or box-shaped) case having a container body 120 with an opening 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 on the Z-axis positive side. The container lid 130 is a rectangular plate-shaped member that is long in the X-axis direction and constitutes the lid of the container 110, and is positioned in the Z-axis positive direction of the container body 120. The container lid 130 is provided with a gas discharge valve 131 that releases pressure when the pressure inside the container 110 rises excessively, and an injection part (not shown) for injecting electrolyte into the container 110. The material of the container 110 (container body 120 and container lid 130) is not particularly limited and can be made of weldable (joinable) metals such as stainless steel, aluminum, aluminum alloy, iron, plated steel sheet, etc., but resin can also be used.

[0038] The container 110 is sealed inside by welding or other means to the container body 120 after the electrode body and other components are housed inside the container body 120. The container 110 has a pair of long sides 111 on both sides in the Y-axis direction, a pair of short sides 112 on both sides in the X-axis direction, and a bottom surface 113 on the Z-axis negative side. The long sides 111 are rectangular planar portions that form the long sides of the container 110 and are positioned 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 planar portions that form the short sides of the container 110 and are positioned opposite the walls of the spacers 200 and the case 300 in the X-axis direction. The short sides 112 are adjacent to the long sides 111 and the bottom surface 113 and have a smaller area than the long sides 111. The bottom surface 113 is a rectangular flat surface that forms the bottom of the container 110, and is positioned opposite the wall of the spacer 200 and the bottom wall of the case 300 in the Z-axis direction. The bottom surface 113 is positioned adjacent to the long side surface 111 and the short side surface 112.

[0039] The electrode terminals 140 are terminal members (positive and negative electrode terminals) of the energy storage element 100, positioned on the container lid 130. Specifically, the electrode terminals 140 are positioned so as to protrude in the positive Z-axis direction from the upper surface (terminal placement surface) of the container lid 130. The electrode terminals 140 are electrically connected to the positive and negative electrode plates of the electrode body via a current collector. In other words, the electrode terminals 140 are metal members that lead the 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 electrode terminals 140 are made of aluminum, aluminum alloy, copper, copper alloy, etc.

[0040] The electrode body is an energy storage element (power generation element) formed by laminating a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate has a positive electrode active material layer formed on a positive electrode base layer which is a current collector foil made of a metal such as aluminum or an aluminum alloy. The negative electrode plate has a negative electrode active material layer formed on a negative electrode base layer which is a current collector foil made of a metal such as copper or a copper alloy. As for the active material used in the positive electrode active material layer and the negative electrode active material layer, any known material can be used as long as it is capable of intercalating and releasing lithium ions. The separator can be a microporous sheet or nonwoven fabric made of resin. In this embodiment, the electrode body is formed by laminating electrode plates (positive electrode plate and negative electrode plate) in the Y-axis direction. The electrode body may be of any form, such as a wound electrode body formed by winding electrode plates (positive electrode plate and negative electrode plate), a laminated (stacked) electrode body formed by laminating a plurality of flat electrode plates, or a bellows-type electrode body in which the electrode plates are folded in a bellows shape.

[0041] The current collector is a conductive current collector (positive electrode current collector and negative electrode current collector) that is electrically and mechanically connected to the electrode terminals 140 and the electrode body. The positive electrode current collector is made of aluminum or an aluminum alloy, similar to the positive electrode base layer of the positive electrode plate of the electrode body, and the negative electrode current collector is made of copper or a copper alloy, similar to the negative electrode base layer of the negative electrode plate of the electrode body.

[0042] [1.2 Description of Spacer 200a] Next, the configuration of the spacer 200a will be described in detail. Figure 4 is a perspective view and a front view showing the configuration of the spacer 200a according to this embodiment. Specifically, Figure 4(a) is a perspective view showing an enlarged view of the spacer 200a shown in Figure 2. Figure 4(b) is a front view showing the configuration when the X-axis positive end of the spacer 200a is viewed from the Y-axis negative direction. Figure 4(c) is a perspective view showing the configuration when the X-axis positive end of the spacer 200a is viewed from the X-axis negative direction. Figure 5 is a perspective view, a rear view, and a side view showing the configuration of the spacer 200a according to this embodiment. Specifically, Figure 5(a) is a perspective view showing the configuration when the spacer 200a is viewed from the Y-axis positive direction. Figure 5(b) is a rear view showing the configuration when both ends of the spacer 200a in the X-axis direction are viewed from the Y-axis positive direction. Figure 5(c) is a side view showing the configuration when the Z-axis central part of the X-axis positive end of the spacer 200a is viewed from the X-axis positive direction. Since all of the multiple spacers 200a in the energy storage unit 10 have the same configuration, Figures 4 and 5 show one spacer 200a, and below, the configuration of one spacer 200a will be described in detail.

[0043] As shown in Figures 4 and 5, the spacer 200a has similar shapes at both ends in the X-axis direction. In other words, the spacer 200a has a shape that is symmetrical with respect to a plane passing through the center position and parallel to the YZ plane. The spacer 200a comprises a spacer body 210 and spacer wall portions 220 to 250.

[0044] The spacer body 210 is a flat, rectangular portion that constitutes the main body of the spacer 200a and is arranged parallel to the XZ plane. In this embodiment, the spacer body 210 is positioned facing the long side 111 in the Y-axis direction and in contact with the long side 111, so as to cover the entire surface of the long side 111 of the container 110 of the energy storage element 100 in the Y-axis positive or Y-axis negative direction of the energy storage element 100. The spacer body 210 has wall portions 211 to 216 that are arranged on both sides of the Z-axis direction and both sides of the X-axis direction of the energy storage element 100.

[0045] The wall portion 211 is a flat plate-shaped portion that protrudes from both ends in the X-axis direction to both sides in the Y-axis direction at the Z-axis positive end of the spacer body 210, and is arranged parallel to the XY plane. The wall portion 211 is positioned in the Z-axis positive direction at both ends in the X-axis direction of the container lid portion 130 of the energy storage element 100, and is positioned opposite the container lid portion 130 in the Z-axis direction. The wall portion 212 is a flat plate-shaped portion that extends in the X-axis direction from one end to the other in the X-axis direction at the Z-axis negative end of the spacer body 210, and protrudes on both sides in the Y-axis direction, and is arranged parallel to the XY plane. The wall portion 212 is positioned in the Z-axis negative direction of the bottom surface 113 of the container 110 of the energy storage element 100, and is positioned opposite the bottom surface 113 in the Z-axis direction.

[0046] The wall portion 213 is a flat plate-shaped portion that protrudes from both ends in the X-axis direction to both sides in the Y-axis direction at the Z-axis positive end of the spacer body 210, and is arranged parallel to the YZ plane. The wall portion 213 is positioned in the X-axis direction of the Z-axis positive end of the short side 112 of the container 110 of the energy storage element 100, facing the short side 112 in the X-axis direction. The wall portion 214 is a flat plate-shaped portion that protrudes from both ends in the X-axis direction to both sides in the Y-axis direction at the Z-axis negative end of the spacer body 210, and is arranged parallel to the YZ plane. The wall portion 214 is positioned in the X-axis direction of the Z-axis negative end of the short side 112 of the container 110 of the energy storage element 100, facing the short side 112 in the X-axis direction. In this way, the wall portions 211 to 214 are arranged to cover the four corners of the energy storage element 100 located at both ends in the Z-axis direction and both ends in the X-axis direction of the energy storage element 100. As a result, the spacer 200a holds the energy storage element 100.

[0047] The wall portion 215 is a flat plate-like portion parallel to the YZ plane, projecting in the positive Y direction, extending in the Z direction from wall portion 213 to wall portion 214 at both ends of the spacer body 210 in the X direction. The wall portion 215 is positioned on both sides in the X direction of the short side 112 of the container 110 of the energy storage element 100 located in the positive Y direction of the spacer body 210, facing the short side 112 in the X direction. The wall portion 216 is a flat plate-like portion parallel to the XY plane, projecting in the positive Y direction, extending in the X direction from wall portion 215 to spacer wall portion 220 or 240. For each of the spacer wall portions 220 and 240, multiple (three in this embodiment) wall portions 216 are arranged in the Z direction. The multiple wall portions 216 have different lengths in the X direction. Specifically, among the multiple wall sections 216, the wall section 216 located in the positive Z-axis direction has a longer length in the X-axis direction than the wall section 216 located in the negative Z-axis direction.

[0048] The spacer wall portion 220 is a plate-like portion that is substantially parallel to the YZ plane and protrudes from the X-axis positive end of the spacer body 210 in the Y-axis positive direction (one side of the first direction), and is arranged from one end to the other in the Z-axis direction of the spacer body 210. In this embodiment, the spacer wall portion 220 is positioned in the X-axis positive direction more than the wall portions 213 and 214 in the X-axis positive direction. The spacer wall portion 220 is positioned in a posture that is slightly tilted in the X-axis direction from the YZ plane as it approaches the Z-axis positive direction (see Figure 5(b), etc.). The spacer wall portion 220 is positioned along the X-axis positive side surface 112 of the container 110 of the energy storage element 100 located in the Y-axis positive direction of the spacer body 210, facing the said short side surface 112 of the energy storage element 100 in the X-axis direction (the second direction intersecting the first direction).

[0049] The spacer wall portion 220 has an opening 221. The opening 221 is a through hole that penetrates the spacer wall portion 220 in the X-axis direction. Specifically, the opening 221 is a through hole that is long in the Y-axis direction, and whose width in the Z-axis direction decreases as it moves toward the Y-axis positive direction (see Figure 5(c), etc.). Specifically, the opening 221 is formed such that the width in the Z-axis direction is larger at the Y-axis negative end and smaller at the Y-axis positive end than the width in the Z-axis direction of the protrusion 232 of the spacer wall portion 230 described later. In this embodiment, two openings 221 are formed in the Z-axis central part of the spacer wall portion 220, aligned in the Z-axis direction.

[0050] The spacer wall portion 230 is a plate-like portion that is substantially parallel to the YZ plane and protrudes from the X-axis positive end of the spacer body 210 in the Y-axis negative direction (the other side of the first direction), and is arranged from one end to the other in the Z-axis direction of the spacer body 210. In this embodiment, the spacer wall portion 230 is positioned more in the X-axis positive direction than the spacer wall portion 220 when viewed from the Y-axis direction. The spacer wall portion 230 is positioned in a posture that is slightly tilted in the X-axis direction from the YZ plane as it approaches the Z-axis positive direction (see Figure 4(b), etc.). In other words, the spacer wall portion 230 is positioned parallel to the spacer wall portion 220. The spacer wall portion 230 is positioned along the X-axis positive side surface 112 of the container 110 of the energy storage element 100 located in the Y-axis negative direction of the spacer body 210, and is positioned opposite the said short side surface 112 of the energy storage element 100 in the X-axis direction (second direction).

[0051] The spacer wall portion 230 has a protruding portion 231 and a convex portion 232. The protruding portion 231 is a plate-like portion parallel to the XZ plane, protruding from the Y-axis minus end of the spacer wall portion 230 in the X-axis plus direction, and extending in the Z-axis direction from one end to the other in the Z-axis direction of the spacer wall portion 230. The protruding portion 231 has a first inclined surface 231a and a second inclined surface 231b on its end face in the X-axis direction (second direction), which are inclined in the X-axis direction (second direction).

[0052] The first inclined surface 231a and the second inclined surface 231b are inclined surfaces that incline in the X-axis direction as they move toward the Z-axis direction, with the second inclined surface 231b being more inclined than the first inclined surface 231a. Specifically, since the spacer wall portion 230 on which the protrusion 231 is provided is inclined in the X-axis direction, the end face in the X-axis direction of the portion of the protrusion 231 with the same width in the X-axis direction is the first inclined surface 231a. The second inclined surface 231b is located in the Z-axis direction of the first inclined surface 231a and is the end face in the X-axis direction of the portion of the protrusion 231 whose width in the X-axis direction decreases as it moves toward the Z-axis direction. The length of the second inclined surface 231b in the Z-axis direction is not particularly limited, but in this embodiment, it is about 1 / 3 to 1 / 5 of the length of the protrusion 231 in the Z-axis direction. In this embodiment, the first inclined surface 231a and the second inclined surface 231b are inclined planes, but they may also be inclined curved surfaces.

[0053] The protrusion 232 is a projection that extends in the negative X-axis direction from the surface of the spacer wall 230 in the negative X-axis direction. The protrusion 232 is circular (i.e., cylindrical) when viewed from the X-axis direction. In this embodiment, two protrusions 232 are formed in the center of the spacer wall 230 in the Z-axis direction, aligned in the Z-axis direction. The position (height) of the protrusion 232 in the Z-axis direction is the same as that of the opening 221 of the spacer wall 220, and the protrusion 232 is positioned in the positive X-axis direction more than the opening 221 when viewed from the Y-axis direction (see Figure 7). The size of the protrusion 232 in the Z-axis direction is smaller than the negative Y-axis end of the opening 221 of the spacer wall 220, and larger than the positive Y-axis end of the opening 221. In the Y-axis direction (first direction), the protrusion 232 is positioned closer to the tip of the spacer wall 230 than to the root. In this embodiment, the protrusion 232 is positioned at the negative Y-axis end of the spacer wall 230. In other words, the convex portion 232 is positioned close to the protruding portion 231, specifically, in a position where at least a portion of it overlaps with the protruding portion 231 when viewed from the X-axis direction (see Figure 7(a)).

[0054] The spacer wall portion 240 is a plate-like portion that is substantially parallel to the YZ plane and protrudes from the X-axis negative end of the spacer body 210 in the Y-axis positive direction (one side of the first direction), and is arranged from one end to the other in the Z-axis direction of the spacer body 210. The spacer wall portion 240 has the same shape as the spacer wall portion 220 and has an opening 241 similar to the opening 221 of the spacer wall portion 220. As described above, the spacer 200a has a shape that is symmetrical with respect to a plane passing through its center position and parallel to the YZ plane, so the spacer wall portion 240 has a shape that is symmetrical with respect to the spacer wall portion 220 with respect to that plane. For this reason, the configuration of the spacer wall portion 240 (and opening 241) is the same as the description of the spacer wall portion 220 (and opening 221) above, with the X-axis positive direction and the X-axis negative direction swapped. Therefore, a detailed explanation of the spacer wall portion 240 (and opening 241) is omitted.

[0055] The spacer wall portion 250 is a plate-like portion that is substantially parallel to the YZ plane and protrudes from the X-axis negative end of the spacer body 210 in the Y-axis negative direction (the other side of the first direction), and is arranged from one end to the other in the Z-axis direction of the spacer body 210. The spacer wall portion 250 has the same shape as the spacer wall portion 230, and has protrusions 251 and 252 similar to the protrusions 231 and 232 of the spacer wall portion 230. The protrusion 251 has a first inclined surface 251a and a second inclined surface 251b similar to the first inclined surface 231a and second inclined surface 231b of the protrusion 231. As described above, since the spacer 200a has a shape that is symmetrical with respect to a plane passing through the center position and parallel to the YZ plane, the spacer wall portion 250 has a shape that is symmetrical with respect to the spacer wall portion 230 with respect to that plane. Therefore, the configuration of the spacer wall portion 250 (and the protruding portion 251, the first inclined surface 251a, the second inclined surface 251b, and the convex portion 252) is the same as that of the spacer wall portion 230 (and the protruding portion 231, the first inclined surface 231a, the second inclined surface 231b, and the convex portion 232) described above, with the X-axis positive direction and the X-axis negative direction swapped. Accordingly, a detailed explanation of the spacer wall portion 250 (and the protruding portion 251, the first inclined surface 251a, the second inclined surface 251b, and the convex portion 252) is omitted.

[0056] As shown in Figure 2, the spacers 200a having the above configuration are arranged alternately with the energy storage elements 100 in the Y-axis direction. The configuration in which the spacers 200a are arranged relative to the energy storage elements 100 will be described in detail below. In this description, as shown in Figure 2, the spacer 200a located in the center of the three spacers 200a arranged in the Y-axis direction will also be referred to as the first spacer 201. The spacer 200a located in the positive Y-axis direction of the first spacer 201 will also be referred to as the second spacer 202. The spacer 200a located in the negative Y-axis direction of the first spacer 201 will also be referred to as the third spacer 203. The first spacer 201, the second spacer 202, and the third spacer 203 have the same configuration.

[0057] [1.3 Explanation of the positional relationship of multiple spacers 200a] Figure 6 is a perspective view showing the configuration of the first spacer 201, second spacer 202, and third spacer 203 according to this embodiment. In Figure 6, the first spacer 201, second spacer 202, and third spacer 203 shown in Figure 2 are shown arranged in the Y-axis direction, but the illustration of the energy storage element 100 is omitted. Figure 7 is a cross-sectional view showing the configuration of the first spacer 201, second spacer 202, and third spacer 203 according to this embodiment. Specifically, Figure 7(a) is a cross-sectional view showing the configuration shown in Figure 6 when cut by a plane passing through the line VIIa-VIIa and parallel to the XY plane. Figure 7(b) is a cross-sectional view showing the configuration shown in Figure 6 and Figure 7(a) when cut by a plane passing through the line VIIb-VIIb and parallel to the XZ plane. Figure 8 is a cross-sectional view showing the configuration of the first spacer 201, second spacer 202, and third spacer 203 according to this embodiment in a deformed state of the spacer wall portion 230. Specifically, Figures 8(a) and 8(b) correspond to Figures 7(a) and 7(b). Figure 9 is a cross-sectional view showing an example of the process by which the spacer wall portion 230 of the second spacer 202 deforms relative to the spacer wall portion 220 of the first spacer 201 according to this embodiment. Specifically, Figure 9(a) corresponds to Figure 7(b) and shows the state before the spacer wall portion 230 deforms, and Figure 9(b) corresponds to Figure 8(b) and shows the state after the spacer wall portion 230 has deformed.

[0058] As shown in Figures 2, 6, and 7, the second spacer 202, the first spacer 201, and the third spacer 203 are arranged in order from the positive Y-axis direction. That is, the first spacer 201 is placed between the second spacer 202 and the third spacer 203. The first spacer 201 and the second spacer 202 sandwich the energy storage element 100 in the Y-axis direction (first direction). The first spacer 201 and the third spacer 203 sandwich the other energy storage element 100 in the Y-axis direction (first direction). As described above, the first spacer 201, the second spacer 202, and the third spacer 203 have the same configuration as spacer 200a. Therefore, the first spacer 201, the second spacer 202, and the third spacer 203 each have a spacer body 210 and spacer wall portions 220 to 250.

[0059] The spacer wall portions 220-250 of the first spacer 201 are also referred to as the first spacer wall portions 220-250. The spacer wall portions 220-250 of the second spacer 202 are also referred to as the second spacer wall portions 220-250. The spacer wall portions 220-250 of the third spacer 203 are also referred to as the third spacer wall portions 220-250. Below, the relationship between the first spacer wall portion 220 and the second spacer wall portion 230 will be explained in detail, while the relationship between the third spacer wall portion 220 and the first spacer wall portion 230 is similar and therefore will be omitted from the explanation. The relationship between the first spacer wall portion 240 and the second spacer wall portion 250, and the relationship between the third spacer wall portion 240 and the first spacer wall portion 250 are also similar and therefore will be omitted from the explanation.

[0060] As described above, the first spacer wall portion 220 of the first spacer 201 protrudes in the positive Y-axis direction (one side of the first direction) and is positioned opposite the energy storage element 100 in the X-axis direction (second direction). The second spacer wall portion 230 of the second spacer 202 protrudes in the negative Y-axis direction (the other side of the first direction) and is positioned opposite the first spacer wall portion 220 in the X-axis direction (second direction). Specifically, the second spacer wall portion 230 is positioned outside the first spacer wall portion 220 (positive X-axis direction). As a result, the protruding portion 231 of the second spacer wall portion 230 is positioned in the positive X-axis direction of the first spacer wall portion 220 and protrudes away from the first spacer wall portion 220 (positive X-axis direction). In this embodiment, the protruding portion 231 of the second spacer wall portion 230 is positioned to overlap with the opening 221 of the first spacer wall portion 220 when viewed from the X-axis direction.

[0061] One of the first spacer wall portion 220 and the second spacer wall portion 230 has a protrusion that projects toward the other in the X-axis direction (second direction), and the other has an opening into which the protrusion is inserted. The protrusion or opening provided on the second spacer wall portion 230 is positioned in the Y-axis direction (first direction) closer to the tip of the second spacer wall portion 230 than to the root. In this embodiment, the second spacer wall portion 230 has a protrusion 232 that projects toward the first spacer wall portion 220 in the X-axis direction, and the first spacer wall portion 220 has an opening 221 into which the protrusion 232 is inserted. The protrusion 232 provided on the second spacer wall portion 230 is positioned in the Y-axis direction closer to the tip of the second spacer wall portion 230 than to the root (closer to the protrusion 231).

[0062] Specifically, the protrusion 232 of the second spacer wall 230 is positioned in the negative X-axis direction of the opening 221 of the first spacer wall 220, and is positioned at the same location as the opening 221 in the Y-axis and Z-axis directions. The size of the protrusion 232 when viewed from the X-axis direction is smaller than that of the opening 221. Therefore, when viewed from the X-axis direction, the protrusion 232 overlaps with the opening 221, and the entire protrusion 232 is positioned within the opening 221. As a result, when the second spacer wall 230 deforms toward the first spacer wall 220, the protrusion 232 is inserted into the opening 221. This will be explained in detail below.

[0063] When the first spacer 201 and the second spacer 202 are placed relative to the energy storage element 100, the spacer wall portion 230 deforms toward the spacer wall portion 220, as shown in Figure 8. In other words, the second spacer wall portion 230 of the second spacer 202 is positioned in a deformed state toward the first spacer wall portion 220 of the first spacer 201. As a result, the protrusion 232 of the second spacer wall portion 230 is inserted into the opening 221 of the first spacer wall portion 220 and fitted (press-fitted). This connects (links, fixes) the second spacer wall portion 230 to the first spacer wall portion 220, and positions the second spacer 202 relative to the first spacer 201.

[0064] The statement that the second spacer wall 230 is positioned in a deformed state toward the first spacer wall 220 means that a force is acting on the second spacer wall 230 in a direction away from the first spacer wall 220, and the movement of the second spacer wall 230 is restricted. In this embodiment, the second spacer wall 230 is positioned in a state of elastic deformation toward the first spacer wall 220, so that an elastic force (restoring force) acts on the second spacer wall 230 in a direction away from the first spacer wall 220. The movement of the second spacer wall 230 is restricted by being fixed to the first spacer wall 220 or another member (such as the wall of the case 300). When the restriction on the movement of the second spacer wall 230 is released, the second spacer wall 230 moves in a direction away from the first spacer wall 220.

[0065] The deformation of the second spacer wall 230 can be performed by an operator pushing the second spacer wall 230 toward the first spacer wall 220 before inserting the first spacer 201 and the second spacer 202 into the case body 310. Even after inserting the first spacer 201 and the second spacer 202 into the case body 310, the operator can deform the second spacer wall 230 by using a jig or the like to push the second spacer wall 230 toward the first spacer wall 220. The second spacer wall 230 can also be deformed when inserting the first spacer 201 and the second spacer 202 into the case body 310. Below, as an example of deforming the second spacer wall 230, the process of deforming the second spacer wall 230 when inserting the first spacer 201 and the second spacer 202 into the case body 310 will be explained using Figure 9.

[0066] When the first spacer 201 and the second spacer 202 are inserted into the case body 310, the side wall of the case body 310 that the second spacer wall portion 230 of the second spacer 202 contacts is referred to as the case wall portion 311 (see Figure 1). The case wall portion 311 is a flat, rectangular wall portion (side wall) that is parallel to the YZ plane and elongated in the Y-axis direction, with its main surface facing the X-axis direction, forming the X-axis side (long side) of the case body 310. The case wall portion 311 is positioned opposite the energy storage unit 10 (energy storage element 100 and spacers 200 (200a, 200b, and 200c)) in the X-axis direction.

[0067] As shown in Figure 9(a), the first spacer 201 and the second spacer 202 are inserted into the case body 310 through the opening 310a of the case body 310. At this time, the second inclined surface 231b is formed on the protruding portion 231 of the second spacer wall portion 230 of the second spacer 202, making insertion easier. When the first spacer 201 and the second spacer 202 are inserted into the case body 310, the protruding portion 231 of the second spacer wall portion 230 of the second spacer 202 comes into contact with the case wall portion 311. At this time, the first spacer 201 and the second spacer 202 are inserted into the case body 310 while the second inclined surface 231b and the first inclined surface 231a, or the first inclined surface 231a, of the protruding portion 231 are in contact with the case wall portion 311. As a result, as shown in Figure 9(b), the second spacer wall portion 230 receives a force from the case wall portion 311 in the negative X-axis direction and elastically deforms in the negative X-axis direction. Specifically, the second spacer wall 230 is bent at the base of its Y-axis positive end, and its Y-axis negative end approaches the first spacer wall 220, so that it is positioned at an angle to the first spacer wall 220 (see Figure 8(a)).

[0068] As a result, the protrusion 232 of the second spacer wall 230 is inserted into the opening 221 of the first spacer wall 220. In this embodiment, the protrusion 232 is inserted into the opening 221 in a direction slightly inclined from the X-axis direction to the Y-axis direction. Specifically, as the second spacer wall 230 deforms and its tip approaches the first spacer wall 220, the Y-axis negative end of the protrusion 232 is inserted into the opening 221, and then the Y-axis positive end of the protrusion 232 is also inserted into the opening 221. As described above, the opening 221 is formed such that the width in the Z-axis direction is larger than the width of the protrusion 232 in the Z-axis direction at the Y-axis negative end, but smaller at the Y-axis positive end. Therefore, when the protrusion 232 is inserted into the opening 221, it is fitted (press-fitted) into the opening 221. At this time, the first spacer wall 220 receives a relatively large force from the second spacer wall 230. Therefore, the wall portions 215 and 216 provided on the spacer body 210 function as support portions that support the first spacer wall portion 220.

[0069] When the first spacer 201 and the second spacer 202 are inserted into the case body 310, the first spacer wall 220 is positioned between the energy storage element 100 and the case wall 311 in the X-axis direction. The second spacer wall 230 is positioned between the first spacer wall 220 and the case wall 311 in the Z-axis direction. The protruding portion 231 of the second spacer wall 230 is positioned to protrude toward the case wall 311. The first inclined surface 231a and the second inclined surface 231b of the protruding portion 231 are inclined so that they move away from the case wall 311 as they move away from the opening 310a of the case body 310. The second spacer wall 230 (protruding portion 231) is positioned to be in contact with the case wall 311 and pushed away from the case wall 311. A separate component, such as an insulating member (insulator), may be placed between the second spacer wall 230 and the case wall 311. In this case, the second spacer wall 230 (protruding portion 231) is positioned in indirect contact with the case wall 311 via the separate component.

[0070] The second spacer wall 230 may be deformed before inserting the first spacer 201 and the second spacer 202 into the case body 310. In this case, the second spacer wall 230 is deformed to fit (press-fit) the protrusion 232 into the opening 221, and with the second spacer wall 230 fixed to the first spacer wall 220, the first spacer 201 and the second spacer 202 are inserted into the case body 310. As a result, the second spacer wall 230 may be positioned without being pressed by the case wall 311, and the second spacer wall 230 may not come into contact with the case wall 311. The same applies when the second spacer wall 230 is deformed after the first spacer 201 and the second spacer 202 have been inserted into the case body 310.

[0071] [2. Explanation of Effects] As described above, the energy storage device 1 according to this embodiment includes a first spacer 201 and a second spacer 202 that sandwich the energy storage element 100. The second spacer 202 has a second spacer wall 230 that faces the first spacer wall 220 of the first spacer 201, and the second spacer wall 230 is positioned in a deformed state toward the first spacer wall 220. In other words, the first spacer 201 and the second spacer 202 are positioned with the second spacer wall 230 separated from the first spacer wall 220, and after the first spacer 201 and the second spacer 202 are positioned, the second spacer wall 230 is deformed toward the first spacer wall 220. In this way, since the first spacer 201 and the second spacer 202 can be positioned with the second spacer wall 230 separated from the first spacer wall 220, contact between the first spacer wall 220 and the second spacer wall 230 can be suppressed when positioning the first spacer 201 and the second spacer 202. This allows the first spacer 201 and the second spacer 202 to be easily positioned, thereby improving the ease of assembly of the energy storage device 1.

[0072] When inserting the first spacer 201 and the second spacer 202 into the case 300 (case body 310), the second spacer wall 230 can be deformed toward the first spacer wall 220 and overlapped during insertion into the case 300. This allows the overlapping of the first spacer wall 220 and the second spacer wall 230 and the insertion of the first spacer 201 and the second spacer 202 into the case 300 to be performed simultaneously, thereby improving the ease of assembly of the energy storage device 1. Since the first spacer wall 220 and the second spacer wall 230 are overlapped on the side of the energy storage element 100, the rigidity of the first spacer 201 and the second spacer 202 on the side of the energy storage element 100 can be increased, improving vibration resistance and shock resistance. In particular, since the second spacer wall 230 is deformed toward the first spacer wall 220, a force acts on the second spacer wall 230 toward the case wall 311. Therefore, vibration resistance and shock resistance at the location of the second spacer wall 230 can be further improved.

[0073] The second spacer wall portion 230 of the second spacer 202 has a protrusion 231 that protrudes away from the first spacer wall portion 220 of the first spacer 201. By pressing the protrusion 231, the second spacer wall portion 230 can be easily deformed toward the first spacer wall portion 220. This allows the second spacer wall portion 230 to be easily positioned in a deformed state toward the first spacer wall portion 220.

[0074] When inserting the first spacer 201 and the second spacer 202 into the case 300 (case body 310), the protruding portion 231 of the second spacer wall portion 230 comes into contact with the case wall portion 311 during insertion, thereby reducing the frictional force between the second spacer 202 and the case wall portion 311. This allows the first spacer 201 and the second spacer 202 to be easily inserted into the case 300.

[0075] Since the first inclined surface 231a and the second inclined surface 231b are formed on the end face of the protruding portion 231 of the second spacer wall portion 230 of the second spacer 202, the second spacer wall portion 230 can be deformed by pressing on the first inclined surface 231a or the second inclined surface 231b. As a result, even when it is difficult to press on the protruding portion 231 from the X-axis direction (second direction), the second spacer wall portion 230 can be easily deformed toward the first spacer wall portion 220 by pressing on the first inclined surface 231a or the second inclined surface 231b.

[0076] When inserting the first spacer 201 and the second spacer 202 into the case 300 (case body 310), the first inclined surface 231a and the second inclined surface 231b are formed on the end face of the protruding portion 231 of the second spacer wall 230, thereby preventing the second spacer wall 230 from contacting the case wall 311. Even if the second spacer wall 230 does contact the case wall 311, the first inclined surface 231a and the second inclined surface 231b contact the case wall 311, resulting in contact along a line rather than a surface, thus reducing the frictional force between the second spacer wall 230 and the case wall 311. As a result, the first spacer 201 and the second spacer 202 can be easily inserted into the case 300.

[0077] The protrusion 232 of one of the first spacer wall 220 and the second spacer wall 230 (the second spacer wall 230) is inserted into the opening 221 of the other (the first spacer wall 220), thereby allowing the first spacer wall 220 and the second spacer wall 230 to be positioned relative to each other. This allows the first spacer 201 and the second spacer 202 to be positioned relative to each other, making it easy to arrange the first spacer 201 and the second spacer 202. When the protrusion 232 of the first spacer wall 220 and the second spacer wall 230 is fitted (press-fitted) into the opening 221, a compressive load is generated on the protrusion 232 and the opening 221 due to the press-fitting, which increases rigidity and improves vibration resistance and shock resistance.

[0078] Because a protrusion 232 is formed near the tip of the second spacer wall 230, the protrusion 232 can be positioned away from the opening 221 before the second spacer wall 230 deforms, thus preventing the protrusion 232 from contacting the opening 221 or its vicinity. This prevents the first spacer wall 220 and the second spacer wall 230 from contacting each other when the first spacer 201 and the second spacer 202 are positioned. When the second spacer wall 230 deforms toward the first spacer wall 220, the tip of the second spacer wall 230 moves more than its base. Therefore, when the protrusion 232 is fitted (press-fitted) into the opening 221, the protrusion 232 moves significantly when the second spacer wall 230 deforms, allowing the protrusion 232 to be easily fitted (press-fitted) into the opening 221.

[0079] The effects of the first spacer wall 220 and the second spacer wall 230 were explained above, but similar effects are also obtained for the third spacer wall 220 and the first spacer wall 230. In addition, similar effects are obtained for the first spacer wall 240 and the second spacer wall 250, and for the third spacer wall 240 and the first spacer wall 250, etc.

[0080] [3 Explanation of variations] Although an embodiment of the present invention, the energy storage device 1, has been described above, the present invention is not limited to the above embodiment. The embodiments disclosed herein are illustrative in all respects, and the scope of the present invention includes all modifications in the sense and scope equivalent to the claims.

[0081] In the above embodiment, the spacer wall portion 230 is positioned at an angle to the spacer wall portion 220, but it may also be positioned parallel to it. Figure 10 is a cross-sectional view showing the configuration of the spacer wall portion 230 of the first spacer 201a, second spacer 202a, and third spacer 203a in a deformed state according to a modified example of this embodiment. Figure 10 corresponds to Figure 8(a). In Figure 10, the figure corresponding to Figure 8(b) is the same as Figure 8(b), so it is omitted from the illustration. As shown in Figure 10, in the deformed state, the spacer wall portion 230 (the second spacer wall portion 230 of the second spacer 202a, etc.) is positioned parallel to the spacer wall portion 220 (the first spacer wall portion 220 of the first spacer 201a, etc.) and makes surface contact. As a result, the convex portion 232 of the spacer wall portion 230 is inserted into the opening 221 of the spacer wall portion 220 in the X-axis direction, and is fitted (press-fitted) relatively firmly. Since the spacer wall portion 220 and the spacer wall portion 230 are in contact over a surface area, the overall strength of the spacer wall portion 220 and the spacer wall portion 230 can also be improved.

[0082] In the above embodiment, the spacer wall portions 220 to 250 of the spacer 200a are positioned facing the short side surface 112 of the container 110 of the energy storage element 100, but they may also be positioned facing the bottom surface 113 of the container 110 or the container lid portion 130.

[0083] In the above embodiment, the spacer body 210 of spacer 200a is assumed to have wall portions 211 to 216, but it is not limited to having all of these wall portions. The spacer body 210 may not have some or all of the wall portions 211 to 214. In other words, spacer 200a may not be a holder for holding the energy storage element 100. The spacer body 210 may not have wall portions 215 or 216.

[0084] In the above embodiment, the spacer 200a is assumed to have spacer wall portions 220 to 250, but it is not limited to having all of these spacer wall portions. The spacer 200a does not have to have spacer wall portions 240 and 250, nor does it have to have spacer wall portions 220 and 230. The spacer 200a may have only one of the spacer wall portions 220 and 230. In other words, of two adjacent spacers 200a, one spacer 200a may have only spacer wall portion 220, and the other spacer 200a may have only spacer wall portion 230. The same applies to spacer wall portions 240 and 250.

[0085] In the above embodiment, the position and shape of the projection 231 of the second spacer wall 230 of the second spacer 202 are not particularly limited. The projection 231 may be provided not at the Y-axis negative end of the second spacer wall 230, but at the Y-axis central part of the second spacer wall 230, or at the Y-axis positive end, etc. The projection 231 does not have to extend from one end to the other in the Z-axis direction of the second spacer wall 230, but a short projection 231 in the Z-axis direction may be provided at the upper, lower, or central part of the second spacer wall 230, etc. The projection 231 does not have a first inclined surface 231a and a second inclined surface 231b; it may not have a first inclined surface 231a, or it may not have a second inclined surface 231b. In other words, the projection 231 may have a non-inclined surface on its end face in the X-axis positive direction. The second spacer wall 230 may not have a projection 231.

[0086] In the above embodiment, the opening 221 in the first spacer wall portion 220 of the first spacer 201 is a through hole into which the protrusion 232 of the second spacer wall portion 230 of the second spacer 202 is inserted. However, the opening 221 may also be a recess into which the protrusion 232 is inserted, or a notch, etc. Two sets of openings 221 and protrusions 232 are provided in the first spacer wall portion 220 and the second spacer wall portion 230, but only one set may be provided, or three or more sets may be provided. The arrangement position of the openings 221 and protrusions 232 is not particularly limited.

[0087] In the above embodiment, the second spacer wall 230 has a protrusion 232 and the first spacer wall 220 has an opening 221 into which the protrusion 232 is inserted. However, the first spacer wall 220 may have a protrusion and the second spacer wall 230 may have an opening into which the protrusion is inserted. In this case, the opening provided in the second spacer wall 230 is positioned in the Y-axis direction closer to the tip of the second spacer wall 230 than to the root. Alternatively, the protrusion or opening provided in the second spacer wall 230 may be positioned not near the tip of the second spacer wall 230, but near the root, or in the center between the root and the tip. It is also possible for both the first spacer wall 220 and the second spacer wall 230 to have no protrusions or openings.

[0088] In the above embodiment, the opening 221 of the first spacer wall 220 and the protrusion 232 of the second spacer wall 230 may have any shape as long as they can be fitted (press-fitted) into each other. The protrusion 232 of the second spacer wall 230 may be inserted into the opening 221 of the first spacer wall 220 without being fitted (press-fitted). In other words, the second spacer wall 230 is deformed by being pressed against the case wall 311 of the case body 310, and the protrusion 232 is inserted and positioned into the opening 221 without being fitted (press-fitted). This also allows the second spacer wall 230 to be positioned relative to the first spacer wall 220.

[0089] In the above embodiment, the second spacer wall portion 230 of the second spacer 202 is positioned outside the first spacer wall portion 220 of the first spacer 201, but it may also be positioned inside the first spacer wall portion 220.

[0090] In the above embodiment, the thickness of the second spacer wall portion 230 may be reduced in the part to be deformed, such as the base of the second spacer wall portion 230, or a notch or through hole may be formed in the part to be deformed.

[0091] In the above embodiment, all spacers 200a are assumed to have the above configuration, but it is not necessary for any of the spacers 200a to have the above configuration.

[0092] In the above embodiment, spacer 200b or spacer 200c may have the same configuration as spacer 200a. That is, any of the multiple spacers 200 may have the same configuration as spacer 200a. For spacer 200b, the thickness of the spacer body in the Y-axis direction is formed to be thicker than that of spacer 200a, but the spacer wall portion may have the same configuration as spacer 200a. For spacer 200c, the configuration may be the same as half of that of spacer 200a in the Y-axis direction.

[0093] In the above embodiment, the spacers 200 (spacers 200a, 200b, and 200c) are arranged alternately in the Y-axis direction with respect to the energy storage element 100, but a configuration in which none of the spacers 200 are arranged is also possible. A configuration in which only two spacers 200 are arranged, sandwiching one or more energy storage elements 100 is also possible.

[0094] In the above embodiment, the case 300 is assumed to have a case body 310 and a lid 320, but it does not have to have a lid 320. In the above embodiment, two energy storage units 10 arranged in the X-axis direction are housed inside the case 300, but it may house three or more energy storage units 10 arranged in the X-axis direction, or it may house only one energy storage unit 10. Multiple energy storage units 10 arranged in the Y-axis direction are housed inside the case 300. In the above embodiment, the energy storage unit 10 may be equipped with restraining members (end plates, side plates, etc.) that restrain multiple energy storage elements 100 and spacers 200.

[0095] The present invention also includes forms constructed by arbitrarily combining the components of the above embodiments and their variations. [Industrial applicability]

[0096] This invention can be applied to energy storage devices equipped with energy storage elements such as lithium-ion secondary batteries. [Explanation of Symbols]

[0097] 1. Energy storage device 10 Energy storage units 100 energy storage elements 110 Container 111 Long side 112 short side 113 Bottom 120 Container body 130 Container lid 131 Gas discharge valve 140 Electrode terminal 200, 200a, 200b, 200c spacers 201, 201a First spacer 202, 202a Second spacer 203, 203a Third spacer 210 Spacer body 211, 212, 213, 214, 215, 216 Wall section 220, 230, 240, 250 Spacer wall section (First spacer wall section, Second spacer wall section, Third spacer wall section) 221, 241 openings 231, 251 protrusion 231a, 251a First slope 231b, 251b second slope 232, 252 Convex parts 300 cases 310 Case Body 310a aperture 311 Case wall section 320 Lid

Claims

1. Energy storage element, The energy storage element is provided with a first spacer and a second spacer that sandwich it in a first direction, The first spacer has a first spacer wall portion that protrudes to one side in the first direction and is positioned opposite the energy storage element in a second direction that intersects the first direction. The second spacer has a second spacer wall portion that protrudes to the other side in the first direction and is positioned opposite to the first spacer wall portion in the second direction. The movement of the second spacer wall is restricted when a force is acting in the second direction that moves it away from the first spacer wall. Energy storage device.

2. Energy storage element, The energy storage element is provided with a first spacer and a second spacer that sandwich it in a first direction, The first spacer has a first spacer wall portion that protrudes to one side in the first direction and is positioned opposite the energy storage element in a second direction that intersects the first direction. The second spacer has a second spacer wall portion that protrudes to the other side in the first direction and is positioned opposite to the first spacer wall portion in the second direction. The second spacer wall is positioned at an angle to the first spacer wall. Energy storage device.

3. The second spacer wall portion has a projection that protrudes in a direction away from the first spacer wall portion. The energy storage device according to claim 1 or 2.

4. The protruding portion has an inclined surface on its end face in the second direction that is inclined in the second direction. The energy storage device according to claim 3.

5. One of the first spacer wall and the second spacer wall has a projection that protrudes toward the other in the second direction, and the other has an opening into which the projection is inserted. The energy storage device according to any one of claims 1 to 4.

6. The protrusion or opening provided on the second spacer wall is positioned in the first direction closer to the tip of the second spacer wall than to the base. The energy storage device according to claim 5.

Images