Energy storage device

Abstract

To provide a power storage device that can improve vibration resistance or impact resistance.SOLUTION: A power storage element 100 includes a first spacer 201 and a second spacer 202 that sandwich the power storage element 100 in the first direction. The first spacer 201 has a first spacer wall portion 220A that protrudes toward the second spacer 202 from one end in a second direction intersecting the first direction, and the second spacer 202 has a second spacer wall portion 230B protruding from one end in the second direction toward the first spacer 201. The first spacer wall portion 220A includes a first wall portion 223 disposed on one side of the second spacer wall portion 230B in the second direction, and a second wall portion 224 that is aligned with the first wall portion 223 in a third direction intersecting the first direction and the second direction and is arranged on the other side of the second spacer wall portion 230B in the second direction.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an electricity storage device including an electricity storage element and a pair of spacers that sandwich the electricity storage element. [Background Art]

[0002] Conventionally, electricity storage devices including an electricity storage element and a pair of spacers that sandwich the electricity storage element have been widely known. For example, Patent Document 1 discloses a battery pack (electricity storage device) including a plurality of battery cells (electricity storage elements) and a plurality of separators (spacers) interposed between adjacent battery cells, wherein the separators cover the outer peripheries of the battery cells to improve insulation between the battery cells. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2008-166191 [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] In an electricity storage device having a configuration in which an electricity storage element is sandwiched between a pair of spacers, it is desired to restrict the movement of the spacers and improve vibration resistance or impact resistance (resistance to external vibration or impact). However, in the electricity storage device having the above conventional configuration, when vibration or impact is applied to the electricity storage device, one spacer may move relative to the other spacer, which may make it impossible to improve vibration resistance or impact resistance.

[0005] The present invention was accomplished by the inventor of the present application newly focusing on the above problems, and an object of the present invention is to provide an electricity storage device capable of improving vibration resistance or impact resistance. [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 toward the second spacer from one end in a second direction intersecting the first direction, and the second spacer has a second spacer wall portion that protrudes toward the first spacer from one end in the second direction, and the first spacer wall portion has a first wall portion arranged on one side of the second spacer wall portion in the second direction, and a second wall portion that is aligned with the first wall portion in a third direction intersecting the first and second directions, and is arranged on the other side of the second spacer wall portion in the second direction. [Effects of the Invention]

[0007] The energy storage device according to the present invention can improve vibration resistance or shock resistance. [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] This is a perspective view showing the configuration of the spacer according to the embodiment. [Figure 5] This is a perspective view showing the configuration of the spacer according to the embodiment. [Figure 6] This is a perspective view showing the configuration of the spacer wall portions of the first spacer, second spacer, and third spacer according to the embodiment. [Figure 7] This is a perspective view showing the configuration of the spacer wall portions of the first spacer, second spacer, and third spacer according to the embodiment. [Figure 8] These are perspective views and cross-sectional views showing the configuration in which the first spacer and second spacer according to the embodiment are placed on the energy storage element. [Figure 9]This is a perspective view showing the configuration of the first spacer according to a modified embodiment. [Figure 10] These are perspective and cross-sectional views showing the configuration in which the first spacer and second spacer, according to a modified embodiment, are placed on the energy storage element. [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 toward the second spacer from one end in a second direction intersecting the first direction, and the second spacer has a second spacer wall portion that protrudes toward the first spacer from one end in the second direction, and the first spacer wall portion has a first wall portion arranged on one side of the second spacer wall portion in the second direction, and a second wall portion that is aligned with the first wall portion in a third direction intersecting the first and second directions, and is arranged on the other side of the second spacer wall portion in the second direction.

[0010] According to this, in the energy storage device, the first spacer wall of the first spacer has a first wall portion positioned on one side of the second spacer wall of the second spacer in the second direction, and a second wall portion positioned on the other side of the second spacer wall in the second direction. As a result, when the first spacer attempts to move to the other side in the second direction, the first wall portion of the first spacer wall comes into contact with the second spacer wall of the second spacer, restricting the movement of the first spacer to the other side in the second direction. When the first spacer attempts to move to one side in the second direction, the second wall portion of the first spacer wall comes into contact with the second spacer wall of the second spacer, restricting the movement of the first spacer to one side in the second direction. In this way, even if vibration or shock in the second direction is applied to the energy storage device, the movement of the first spacer can be restricted in both directions, one side and the other side in the second direction, thereby improving the vibration resistance or shock resistance of the energy storage device.

[0011] The first spacer wall portion may further include a third wall portion located on one side of the second spacer wall portion in the second direction, at a position where the second wall portion is sandwiched between the first spacer wall portion and the third spacer wall portion, and at least one of the third wall portions located on the other side of the second spacer wall portion in the second direction, at a position where the first wall portion is sandwiched between the second spacer wall portion and the second spacer wall portion.

[0012] When the third wall is positioned on one side of the second spacer wall in the second direction, sandwiching the second wall between the first and second walls, the first and third walls restrict the movement of the first spacer to the other side in the second direction, and the second wall restricts the movement of the first spacer to the other side in the second direction. When the third wall is positioned on the other side of the second spacer wall in the second direction, sandwiching the first wall between the second and second walls, the second and third walls restrict the movement of the first spacer to one side in the second direction, and the first wall restricts the movement of the first spacer to the other side in the second direction. As a result, the movement of the first spacer to one side and the other side in the second direction can be alternately restricted by the first, second, and third walls, thereby further improving the vibration resistance or shock resistance of the energy storage device.

[0013] The energy storage device further comprises a third spacer, the first spacer being positioned between the second spacer and the third spacer, the first spacer having a third spacer wall portion projecting toward the third spacer from one end in the second direction, the third spacer having a fourth spacer wall portion projecting toward the first spacer from one end in the second direction, and the third spacer wall portion may have a fourth wall portion positioned on the other side of the fourth spacer wall portion in the second direction, and a fifth wall portion positioned alongside the fourth wall portion in the third direction and on one side of the fourth spacer wall portion in the second direction.

[0014] According to this, the third spacer wall of the first spacer has a fourth wall positioned on the other side of the fourth spacer wall of the third spacer in the second direction, and a fifth wall positioned on one side of the fourth spacer wall in the second direction. As a result, when the first spacer attempts to move to one side in the second direction, the fourth wall of the third spacer wall contacts the fourth spacer wall of the third spacer, restricting the movement of the first spacer to that side in the second direction. When the first spacer attempts to move to the other side in the second direction, the fifth wall of the third spacer wall contacts the fourth spacer wall of the third spacer, restricting the movement of the first spacer to the other side in the second direction. In this way, even on the other side of the first direction of the first spacer, the movement of the first spacer in both directions (one side and the other side) in the second direction can be restricted. Therefore, even if vibration or shock in the second direction is applied to the energy storage device, the movement of the first spacer can be restricted on both the one side and the other side in the first direction of the first spacer, thus further improving the vibration resistance or shock resistance of the energy storage device.

[0015] The first spacer has a fifth spacer wall portion that protrudes toward the second spacer from the other end in the second direction, the second spacer has a sixth spacer wall portion that protrudes toward the first spacer from the other end in the second direction, and the fifth spacer wall portion may have a sixth wall portion located on the other side of the sixth spacer wall portion in the second direction, and a seventh wall portion that is aligned with the sixth wall portion in the third direction and located on one side of the sixth spacer wall portion in the second direction.

[0016] According to this, the fifth spacer wall portion of the first spacer includes: a sixth wall portion disposed on the other side in the second direction of the sixth spacer wall portion of the second spacer; and a seventh wall portion disposed on one side in the second direction of the sixth spacer wall portion. Accordingly, when the first spacer tends to move toward the one side in the second direction, the sixth wall portion of the fifth spacer wall portion comes into contact with the sixth spacer wall portion of the second spacer, thereby restricting the movement of the first spacer toward the one side in the second direction. When the first spacer tends to move toward the other side in the second direction, the seventh wall portion of the fifth spacer wall portion comes into contact with the sixth spacer wall portion of the second spacer, thereby restricting the movement of the first spacer toward the other side in the second direction. In this way, even on the other side in the second direction of the first spacer, the movement of the first spacer in both directions of the one side and the other side in the second direction can be restricted. Therefore, even if vibration or impact in the second direction is applied to the power storage device, the movement of the first spacer can be restricted on both the one side and the other side in the second direction of the first spacer, so that the vibration resistance or impact resistance of the power storage device can be further improved.

[0017] A recess recessed toward the other side in the second direction may be formed at a position of the second spacer wall portion facing the first wall portion, and the first wall portion may be disposed in the recess.

[0018] According to this, the first wall portion of the first spacer wall portion of the first spacer is disposed in a recess that is formed in the second spacer wall portion of the second spacer and is recessed in the second direction. Accordingly, when the first spacer tends to move in a direction intersecting the second direction, the first wall portion comes into contact with the wall of the recess, thereby restricting the movement of the first spacer. Therefore, the movement of the first spacer can be restricted even in the direction intersecting the second direction, so that the vibration resistance or impact resistance of the power storage device can be further improved.

[0019] At least one of the first wall portion and the wall portion of the second spacer wall portion facing the first wall portion may include a rib protruding toward the other.

[0020] According to this, by providing ribs on at least one of the first wall portion of the first spacer and the wall portion of the second spacer facing the first wall portion, the gap between the first wall portion and the wall portion can be filled with the ribs. In a configuration in which the energy storage element is cooled with a refrigerant (such as air), the ribs can form a flow path for the refrigerant between the first wall portion and the wall portion.

[0021] The following description of an energy storage device according to an embodiment (including its modifications) of the present invention will be given with reference to the drawings. The embodiments described below are all general or specific examples. The numerical values, shapes, materials, components, arrangement and connection configurations of components, manufacturing processes, and the order of manufacturing processes shown in the following embodiments are examples and are not intended to limit the present invention. Dimensions and other specifications are not strictly illustrated in each figure. In each figure, the same or similar components are denoted by the same reference numerals.

[0022] In the following description and drawings, the direction in which the pair of electrode terminals of an energy storage element are aligned, the direction in which the pair of short sides of the container of the energy storage element are aligned, or the direction in which the energy storage unit is aligned is defined as the X-axis direction. The direction in which the pair of long sides of the container of the energy storage element are aligned, the thickness direction (flattening direction) of the container of the energy storage element, the direction in which the multiple energy storage elements of the energy storage unit are aligned, or the direction in which the energy storage elements and spacers of the energy storage unit are aligned is defined as the Y-axis direction. The direction in which the electrode terminals of the energy storage element protrude, the direction in which the container body and the container lid of the energy storage element are aligned, the direction in which the case body and the lid of the case are aligned, the direction in which the opening and the bottom wall of the case body are aligned, or the vertical direction is defined as the Z-axis direction. These X-axis, Y-axis, and Z-axis directions intersect each other (orthogonal in this embodiment). Depending on the usage, the Z-axis direction may not be the vertical direction, but for the sake of explanation below, the Z-axis direction will be described as the vertical direction.

[0023] 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 either direction. 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. In the following, the Y-axis direction will also be called the first direction, the X-axis direction the second direction, and the Z-axis direction the third 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, when two directions are parallel, it means not only that the two directions are perfectly parallel, but also that they are substantially parallel, i.e., that they include a difference of, for example, a few percent. In the following explanation, when the term "insulation" is used, it means "electrical insulation".

[0024] (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).

[0025] 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.

[0026] 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.

[0027] 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.

[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 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.

[0029] 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, 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 functions as a holder to hold the energy storage element 100 and position it. The spacer 200 also has a flow path for a coolant (such as air) to flow through, and has the function of cooling the energy storage element 100.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] Next, the configuration of the energy storage element 100 and the spacer 200a will be described in detail.

[0037] [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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] [1.2 Description of Spacer 200a] Next, the configuration of the spacer 200a will be described in detail. Figures 4 and 5 are perspective views showing the configuration of the spacer 200a according to this embodiment. Specifically, Figure 4(a) shows an enlarged view of the spacer 200a shown in Figure 2. Figure 4(b) shows a further enlarged view of the configuration of the X-axis positive end of the spacer 200a shown in Figure 4(a), and Figure 4(c) shows a further enlarged view of the configuration of the X-axis negative end of the spacer 200a shown in Figure 4(a). Figure 5(a) shows the configuration on the opposite side of the spacer 200a shown in Figure 4(a) (configuration when viewed from the Y-axis positive direction). Figure 5(b) shows a further enlarged view of the configuration of the X-axis negative end of the spacer 200a shown in Figure 5(a), and Figure 5(c) shows a further enlarged view of the X-axis positive end of the spacer 200a shown in Figure 5(a). 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.

[0045] As shown in Figures 4 and 5, the spacer 200a has a similar shape 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 270.

[0046] 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 positive or negative Y-axis direction of the energy storage element 100.

[0047] The spacer body 210 has multiple L-shaped curved grooves 211 to 219 through which a refrigerant (a gas such as air or a cooling fluid such as liquid) passes. Grooves 211 to 215 are formed on the Y-axis negative side of the spacer body 210, while grooves 216 to 219 are formed on the Y-axis positive side of the spacer body 210. At the Z-axis negative end of each of the grooves 211 to 219, slit-shaped openings 211a to 219a extending in the X-axis direction are formed.

[0048] As shown in Figure 4, groove 211 extends in the positive Z-axis direction from the X-axis positive end (opening 211a) at the Z-axis negative edge of the spacer body 210, and curves in the X-axis positive direction to extend in the X-axis positive direction. Groove 212 extends in the positive Z-axis direction from a portion (opening 212a) further in the X-axis negative direction than groove 211 at the Z-axis negative edge of the spacer body 210, and curves in the X-axis positive direction to extend in the X-axis positive direction. Groove 213 extends in the positive Z-axis direction from the X-axis central part (opening 213a) at the Z-axis negative edge of the spacer body 210, branches to both sides in the X-axis direction, and curves to both sides in the X-axis direction to extend in both directions in the X-axis direction. Groove 214 is a groove that extends in the positive Z-axis direction from a portion (opening 214a) in the negative X-axis direction from groove 213 at the Z-axis negative edge of the spacer body 210, and curves in the negative X-axis direction to extend in the negative X-axis direction. Groove 215 is a groove that extends in the positive Z-axis direction from the X-axis negative end (opening 215a) at the Z-axis negative edge of the spacer body 210, and curves in the negative X-axis direction to extend in the negative X-axis direction.

[0049] As shown in Figure 5, groove 216 extends in the positive Z-axis direction from a portion of the Z-axis-negative edge of the spacer body 210 closer to the X-axis-positive direction (opening 216a), and curves in the X-axis-positive direction to extend in the X-axis-positive direction. Groove 217 extends in the positive Z-axis direction from a portion of the Z-axis-negative edge of the spacer body 210 further in the X-axis-negative direction than groove 216 (opening 217a), and curves in the X-axis-positive direction to extend in the X-axis-positive direction. Groove 218 extends in the positive Z-axis direction from a portion of the Z-axis-negative edge of the spacer body 210 further in the X-axis-negative direction than groove 217 (opening 218a), and curves in the X-axis-negative direction to extend in the X-axis-negative direction. The groove 219 extends in the positive Z-axis direction from a portion (opening 219a) on the Z-axis negative edge of the spacer body 210 that is closer to the X-axis negative direction, and is curved in the X-axis negative direction to extend in the X-axis negative direction.

[0050] The spacer wall portion 220 is a plate-shaped portion parallel to the YZ plane that protrudes in the positive Y direction from the X-axis positive end of the spacer body 210, and is arranged from one end to the other in the Z-axis direction. The spacer wall portion 220 is arranged along the short side 112 in the positive X direction of the container 110 of the energy storage element 100 located in the positive Y direction of the spacer body 210, and is positioned opposite the short side 112 in the X-axis direction. The spacer wall portion 230 is a plate-shaped portion parallel to the YZ plane that protrudes in the negative Y direction from the X-axis positive end of the spacer body 210, and is arranged from one end to the other in the Z-axis direction. The spacer wall portion 230 is arranged along the short side 112 in the positive X direction of the container 110 of the energy storage element 100 located in the negative Y direction of the spacer body 210, and is positioned opposite the short side 112 in the X-axis direction.

[0051] The spacer wall portion 240 is a plate-like portion parallel to the YZ plane that protrudes in the positive Y direction from the X-axis negative end of the spacer body 210, and is arranged from one end to the other in the Z-axis direction. The spacer wall portion 240 is arranged along the X-axis negative short side 112 of the container 110 of the energy storage element 100 located in the Y-axis positive direction of the spacer body 210, and is positioned opposite the short side 112 in the X-axis direction. The spacer wall portion 250 is a plate-like portion parallel to the YZ plane that protrudes in the Y-axis negative direction from the X-axis negative end of the spacer body 210, and is arranged from one end to the other in the Z-axis direction. The spacer wall portion 250 is arranged along the X-axis negative short side 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 short side 112 in the X-axis direction.

[0052] The spacer wall portion 260 is a plate-shaped portion that protrudes from both ends in the X-axis direction at the Z-axis positive end of the spacer body 210 to both ends in the Y-axis direction, and is arranged parallel to the XY plane. The spacer wall portion 260 is arranged along the container lid portion 130 of the container 110 of the energy storage element 100 located on both sides of the Y-axis direction of the spacer body 210, and is positioned opposite the container lid portion 130 in the Z-axis direction. The spacer wall portion 270 is a plate-shaped portion that protrudes from both ends in the Y-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 extends in the X-axis direction, and is arranged parallel to the XY plane. The spacer wall portion 270 is arranged along the bottom surface 113 of the container 110 of the energy storage element 100 located on both sides of the Y-axis direction of the spacer body 210, and is positioned opposite the bottom surface 113 in the Z-axis direction from one end to the other in the X-axis direction of the bottom surface 113.

[0053] As described above, the spacer walls 220 to 270 are arranged to cover both sides of the energy storage element 100 in the X-axis direction and both sides in the Z-axis direction. This allows the spacer 200a to hold the energy storage element 100. The configuration of the spacer walls 220 to 250 will be further described below, with reference to Figures 6 to 8. 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.

[0054] [1.3 Explanation of Spacer Wall Sections 220-250] Figure 6 is a perspective view showing the configuration of the spacer wall portions 220 and 230 of the first spacer 201, second spacer 202, and third spacer 203 according to this embodiment. Figure 6 shows the configuration of the X-axis positive end of the first spacer 201, second spacer 202, and third spacer 203 arranged in the Y-axis direction. Figure 7 is a perspective view showing the configuration of the spacer wall portions 240 and 250 of the first spacer 201, second spacer 202, and third spacer 203 according to this embodiment. Figure 7 shows the configuration of the X-axis negative end of the first spacer 201, second spacer 202, and third spacer 203 arranged in the Y-axis direction. Figure 8 is a perspective view and a cross-sectional view showing the configuration of the first spacer 201 and second spacer 202 according to this embodiment when they are placed on the energy storage element 100. Specifically, Figure 8(a) is a perspective view showing the energy storage element 100 sandwiched between the first spacer 201 and the second spacer 202. Figure 8(b) is a cross-sectional view showing the configuration shown in Figure 8(a) when it is cut by a plane passing through the line VIIIb-VIIIb and parallel to the XY plane. Figure 8(c) is a cross-sectional view showing the configuration shown in Figure 8(a) when it is cut by a plane passing through the line VIIIc-VIIIc and parallel to the XY plane.

[0055] 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 spacer wall portions 220 to 250.

[0056] The spacer walls 220 and 240 of the first spacer 201 protrude toward the second spacer 202 in the positive Y-axis direction, and the spacer walls 230 and 250 of the first spacer 201 protrude toward the third spacer 203 in the negative Y-axis direction. The spacer walls 220, 230, 240, and 250 of the first spacer 201 are referred to as the first spacer wall 220A, the third spacer wall 230A, the fifth spacer wall 240A, and the seventh spacer wall 250A, respectively. In other words, the first spacer 201 has a first spacer wall 220A that protrudes toward the second spacer 202 from its end in the positive X-axis direction (one side of the second direction intersecting the first direction). The first spacer 201 also has a third spacer wall 230A that protrudes toward the third spacer 203 from its end in the positive X-axis direction (one side of the second direction). The first spacer 201 has a fifth spacer wall portion 240A that protrudes toward the second spacer 202 from its end in the negative X-axis direction (the other side of the second direction). The first spacer 201 also has a seventh spacer wall portion 250A that protrudes toward the third spacer 203 from its end in the negative X-axis direction (the other side of the second direction).

[0057] The spacer walls 230 and 250 of the second spacer 202 protrude toward the first spacer 201 in the negative Y-axis direction. These spacer walls 230 and 250 of the second spacer 202 are referred to as the second spacer wall 230B and the sixth spacer wall 250B, respectively. In other words, the second spacer 202 has a second spacer wall 230B that protrudes toward the first spacer 201 from its end in the positive X-axis direction (one side of the second direction). The second spacer 202 also has a sixth spacer wall 250B that protrudes toward the first spacer 201 from its end in the negative X-axis direction (the other side of the second direction). The spacer walls 220 and 240 of the second spacer 202 are referred to as spacer walls 220B and 240B, respectively.

[0058] The spacer walls 220 and 240 of the third spacer 203 protrude toward the first spacer 201 in the positive Y-axis direction. These spacer walls 220 and 240 of the third spacer 203 are referred to as the fourth spacer wall 220C and the eighth spacer wall 240C, respectively. In other words, the third spacer 203 has a fourth spacer wall 220C that protrudes toward the first spacer 201 from its end in the positive X-axis direction (one side of the second direction). The third spacer 203 also has an eighth spacer wall 240C that protrudes toward the first spacer 201 from its end in the negative X-axis direction (the other side of the second direction). The spacer walls 230 and 250 of the third spacer 203 are referred to as spacer walls 230C and 250C, respectively.

[0059] As shown in Figures 4 and 5, in spacer 200a, spacer wall 220 has wall sections 221 to 227, spacer wall 230 has wall sections 231 to 237, spacer wall 240 has wall sections 241 to 247, and spacer wall 250 has wall sections 251 to 257. Therefore, as shown in Figures 6 and 7, the first spacer 201, second spacer 202, and third spacer 203 also have these wall sections. The following explanation of these wall sections will use the first spacer 201 as an example, but the same applies to the second spacer 202 and third spacer 203.

[0060] The first spacer wall portion 220A of the first spacer 201 has wall portions 221 to 227. Wall portion 221 is a flat, plate-shaped wall parallel to the YZ plane that protrudes in the Y-axis direction from the Z-axis positive end of the first spacer wall portion 220A. A recess is formed in wall portion 221 that is recessed in the Y-axis negative direction, and a protrusion formed on wall portion 231 of the second spacer wall portion 230B of the second spacer 202 is inserted into this recess (see Figure 8). Wall portion 227 is a flat, plate-shaped wall parallel to the YZ plane that protrudes in the Y-axis positive direction from the Z-axis negative end of the first spacer wall portion 220A. A recess is formed in wall portion 227 that is recessed in the Y-axis negative direction, and a protrusion formed on wall portion 237 of the second spacer wall portion 230B of the second spacer 202 is inserted into this recess (see Figure 8). These arrangements position the first spacer wall 220A and the second spacer wall 230B relative to each other.

[0061] The wall portion 222 is a flat, rectangular wall parallel to the YZ plane, projecting in the positive Y-axis direction from the portion of the wall portion 221 in the negative Z-axis direction of the first spacer wall portion 220A. In this embodiment, the wall portion 222 is also referred to as the third wall portion 222. The third wall portion 222 is positioned to sandwich the first wall portion 223 between the second wall portion 224 and the third wall portion 222. Furthermore, the third wall portion 222 is positioned in the negative X-axis direction (the other side of the second direction) of the second spacer wall portion 230B of the second spacer 202. Specifically, the third wall portion 222 is positioned in the negative X-axis direction of the wall portion 232 of the second spacer wall portion 230B. In this embodiment, the third wall portion 222 is positioned in contact with the wall portion 232 of the second spacer wall portion 230B (see Figure 8(b)).

[0062] The wall portion 223 is a flat, rectangular wall parallel to the YZ plane, projecting in the positive Y-axis direction from the portion of the third wall portion 222 in the negative Z-axis direction of the first spacer wall portion 220A. In this embodiment, the wall portion 223 is also referred to as the first wall portion 223. The first wall portion 223 is positioned to project further in the positive X-axis direction than the third wall portion 222. Furthermore, the first wall portion 223 is positioned in the positive X-axis direction (one side of the second direction) of the second spacer wall portion 230B of the second spacer 202. Specifically, the first wall portion 223 is positioned in the positive X-axis direction of the wall portion 233 of the second spacer wall portion 230B. In this embodiment, the first wall portion 223 is positioned in contact with the wall portion 233 of the second spacer wall portion 230B (see Figure 8(c)).

[0063] The wall portion 224 is a flat, rectangular wall parallel to the YZ plane, projecting in the positive Y-axis direction from the portion of the first wall portion 223 in the negative Z-axis direction of the first spacer wall portion 220A. In this embodiment, the wall portion 224 is also referred to as the second wall portion 224. The second wall portion 224 is aligned with the first wall portion 223 in the Z-axis direction (the first direction and the third direction intersecting the second direction), and is positioned at the same location as the third wall portion 222 in the X-axis direction, that is, recessed in the negative X-axis direction compared to the first wall portion 223. Furthermore, the second wall portion 224 is positioned in the negative X-axis direction (the other side of the second direction) of the second spacer wall portion 230B of the second spacer 202. Specifically, the second wall portion 224 is positioned in the negative X-axis direction of the wall portion 234 of the second spacer wall portion 230B. In this embodiment, the second wall portion 224 is positioned in contact with the wall portion 234 of the second spacer wall portion 230B.

[0064] The wall portion 225 is a flat, rectangular wall parallel to the YZ plane, projecting in the positive Y-axis direction from the portion of the second wall portion 224 in the negative Z-axis direction of the first spacer wall portion 220A. In this embodiment, the wall portion 225 is also referred to as the third wall portion 225. The third wall portion 225 is positioned to sandwich the second wall portion 224 between the first wall portion 223 and the third wall portion 225. The third wall portion 225 is positioned in the same position as the first wall portion 223 in the X-axis direction, that is, it is positioned to project further in the positive X-axis direction than the third wall portion 222 and the second wall portion 224. Furthermore, the third wall portion 225 is positioned in the positive X-axis direction (one side of the second direction) of the second spacer wall portion 230B of the second spacer 202. Specifically, the third wall portion 225 is positioned in the positive X-axis direction of the wall portion 235 of the second spacer wall portion 230B. In this embodiment, the third wall portion 225 is positioned in contact with the wall portion 235 of the second spacer wall portion 230B.

[0065] The wall portion 226 is a flat, rectangular wall parallel to the YZ plane, projecting in the positive Y-axis direction from the portion of the third wall portion 225 in the negative Z-axis direction of the first spacer wall portion 220A. The wall portion 226 is positioned in the same location as the third wall portion 222 and the second wall portion 224 in the X-axis direction, that is, recessed in the negative X-axis direction compared to the first wall portion 223 and the third wall portion 225. Furthermore, the wall portion 226 is positioned in the negative X-axis direction (the other side of the second direction) of the second spacer wall portion 230B of the second spacer 202. Specifically, the wall portion 226 is positioned in the negative X-axis direction of the wall portion 236 of the second spacer wall portion 230B. In this embodiment, the wall portion 226 is positioned in contact with the wall portion 236 of the second spacer wall portion 230B.

[0066] The third spacer wall portion 230A of the first spacer 201 has wall portions 231 to 237. Wall portion 231 is a flat, plate-shaped wall parallel to the YZ plane, projecting in the Y-axis-negative direction from the Z-axis-positive end of the third spacer wall portion 230A. Wall portion 231 has a protrusion that projects in the Y-axis-negative direction, and this protrusion is inserted into a recess formed in wall portion 221 of the fourth spacer wall portion 220C of the third spacer 203. Wall portion 237 is a flat, plate-shaped wall parallel to the YZ plane, projecting in the Y-axis-negative direction from the Z-axis-negative end of the third spacer wall portion 230A. Wall portion 237 has a protrusion that projects in the Y-axis-negative direction, and this protrusion is inserted into a recess formed in wall portion 227 of the fourth spacer wall portion 220C of the third spacer 203. As a result, the third spacer wall portion 230A and the fourth spacer wall portion 220C are positioned relative to each other.

[0067] The wall portion 232 is a flat, rectangular wall parallel to the YZ plane, projecting in the negative Y-axis direction from the portion of the wall portion 231 in the negative Z-axis direction of the third spacer wall portion 230A. The wall portion 232 is positioned in the positive X-axis direction (one side of the second direction) of the fourth spacer wall portion 220C of the third spacer 203. Specifically, the wall portion 232 is positioned in the positive X-axis direction of the wall portion 222 of the fourth spacer wall portion 220C. In this embodiment, the wall portion 232 is positioned in contact with the wall portion 222 of the fourth spacer wall portion 220C.

[0068] The wall portion 233 is a flat, rectangular wall parallel to the YZ plane, projecting in the negative Y-axis direction from the portion of the wall portion 232 in the negative Z-axis direction of the third spacer wall portion 230A. In this embodiment, the wall portion 233 is also referred to as the fourth wall portion 233. The fourth wall portion 233 is positioned recessed in the negative X-axis direction compared to the wall portion 232. Furthermore, the fourth wall portion 233 is positioned in the negative X-axis direction (the other side of the second direction) of the fourth spacer wall portion 220C of the third spacer 203. Specifically, the fourth wall portion 233 is positioned in the negative X-axis direction of the wall portion 223 of the fourth spacer wall portion 220C. In this embodiment, the fourth wall portion 233 is positioned in contact with the wall portion 223 of the fourth spacer wall portion 220C.

[0069] The wall portion 234 is a flat, rectangular wall parallel to the YZ plane, projecting in the negative Y-axis direction from the portion of the wall portion 233 in the negative Z-axis direction of the third spacer wall portion 230A. In this embodiment, the wall portion 234 is also referred to as the fifth wall portion 234. The fifth wall portion 234 is aligned with the fourth wall portion 233 in the Z-axis direction (third direction) and is positioned at the same location as the wall portion 232 in the X-axis direction, that is, it is positioned to project further in the positive X-axis direction than the fourth wall portion 233. Furthermore, the fifth wall portion 234 is positioned in the positive X-axis direction (one side of the second direction) of the fourth spacer wall portion 220C of the third spacer 203. Specifically, the fifth wall portion 234 is positioned in the positive X-axis direction of the wall portion 224 of the fourth spacer wall portion 220C. In this embodiment, the fifth wall portion 234 is positioned in contact with the wall portion 224 of the fourth spacer wall portion 220C.

[0070] The wall portion 235 is a flat, rectangular wall parallel to the YZ plane, projecting in the negative Y-axis direction from the portion of the wall portion 234 in the third spacer wall portion 230A that is in the negative Z-axis direction. The wall portion 235 is positioned in the same location as the fourth wall portion 233 in the X-axis direction, that is, recessed in the negative X-axis direction compared to the wall portions 232 and the fifth wall portion 234. Furthermore, the wall portion 235 is positioned in the negative X-axis direction (the other side of the second direction) of the fourth spacer wall portion 220C of the third spacer 203. Specifically, the wall portion 235 is positioned in the negative X-axis direction of the wall portion 225 of the fourth spacer wall portion 220C. In this embodiment, the wall portion 235 is positioned in contact with the wall portion 225 of the fourth spacer wall portion 220C.

[0071] The wall portion 236 is a flat, rectangular wall parallel to the YZ plane, projecting in the negative Y-axis direction from the portion of wall portion 235 in the third spacer wall portion 230A that is in the negative Z-axis direction. The wall portion 236 is positioned in the same location as wall portions 232 and fifth wall portion 234 in the X-axis direction, that is, it is positioned to project further in the positive X-axis direction than the fourth wall portion 233 and wall portion 235. Furthermore, the wall portion 236 is positioned in the positive X-axis direction (one side of the second direction) of the fourth spacer wall portion 220C of the third spacer 203. Specifically, the wall portion 236 is positioned in the positive X-axis direction of the wall portion 226 of the fourth spacer wall portion 220C. In this embodiment, the wall portion 236 is positioned in contact with the wall portion 226 of the fourth spacer wall portion 220C.

[0072] As described above, in the spacer wall portion 220 of spacer 200a, the wall portions 222 to 226 aligned in the Z-axis direction are arranged to alternately protrude and recess in the X-axis direction. In the spacer wall portion 230, the wall portions 232 to 236 aligned in the Z-axis direction are arranged to alternately protrude and recess in the X-axis direction, with the order of protrusions and recesses being reversed compared to the wall portions 222 to 226 of spacer wall portion 220. As a result, in two adjacent spacers 200a, the protruding wall portion of the spacer wall portion 220 of one spacer 200a is positioned within the recess formed by the recessed wall portion of the spacer wall portion 230 of the other spacer 200a. Specifically, the first wall portion 223 of the first spacer wall portion 220A of the first spacer 201, which protrudes in the positive X-axis direction, is positioned within the recess formed by the wall portion 233 of the second spacer wall portion 230B of the second spacer 202, which is recessed in the negative X-axis direction. In other words, a recess is formed in the second spacer wall 230B at the position opposite the first wall 223, extending in the negative X-axis direction (the other side of the second direction), and the first wall 223 is positioned within this recess. The same applies to the other wall sections.

[0073] Furthermore, the wall portions 222-226 of the first spacer wall portion 220A of the first spacer 201 have an inclined or curved shape at the tip of the surface facing the wall portions 232-236 of the second spacer wall portion 230B of the second spacer 202. Similarly, the wall portions 232-236 of the second spacer wall portion 230B have an inclined or curved shape at the tip of the surface facing the wall portions 222-226 of the first spacer wall portion 220A. As a result, the protruding wall portions of the wall portions 232-236 of the second spacer wall portion 230B and the wall portions 222-226 of the first spacer wall portion 220A are easily inserted into the recessed wall portions.

[0074] The fifth spacer wall portion 240A of the first spacer 201 has wall portions 241 to 247. The seventh spacer wall portion 250A of the first spacer 201 has wall portions 251 to 257. As described above, the first spacer 201 has a shape that is symmetrical with respect to a plane passing through the center position and parallel to the YZ plane. For this reason, the wall portions 241 to 247 of the fifth spacer wall portion 240A have a shape that is symmetrical with respect to the said plane to the wall portions 221 to 227 of the first spacer wall portion 220A. In other words, the wall portions 241 to 247 of the fifth spacer wall portion 240A are configured by replacing "X-axis negative direction" with "X-axis positive direction" and "X-axis positive direction" with "X-axis negative direction" in the description of the wall portions 221 to 227 of the first spacer wall portion 220A described above. Similarly, the wall portions 251-257 of the seventh spacer wall portion 250A have a shape that is symmetrical to the wall portions 231-237 of the third spacer wall portion 230A with respect to that surface. In other words, the wall portions 251-257 of the seventh spacer wall portion 250A have a configuration in which the "minus X-axis direction" described above for the wall portions 231-237 of the third spacer wall portion 230A is replaced with the "positive X-axis direction," and the "positive X-axis direction" is replaced with the "minus X-axis direction."

[0075] In this embodiment, the wall portion 243 of the fifth spacer wall portion 240A is also referred to as the sixth wall portion 243, and the wall portion 244 of the fifth spacer wall portion 240A is also referred to as the seventh wall portion 244. The sixth wall portion 243 is positioned in the negative X-axis direction (the other side of the second direction) of the sixth spacer wall portion 250B of the second spacer 202. Specifically, the sixth wall portion 243 is positioned in the negative X-axis direction of the wall portion 253 of the sixth spacer wall portion 250B, in contact with the wall portion 253. The seventh wall portion 244 is positioned alongside the sixth wall portion 243 in the Z-axis direction (third direction) and is positioned in the positive X-axis direction (one side of the second direction) of the sixth spacer wall portion 250B of the second spacer 202. Specifically, the seventh wall portion 244 is positioned in contact with the wall portion 254 of the sixth spacer wall portion 250B in the positive X-axis direction of the wall portion 254.

[0076] Furthermore, in this embodiment, slit-shaped openings 232a, 223a, 234a, 225a, and 236a extending in the Z-axis direction are formed between the wall portions 232, 223, 234, 225, and 236 and the spacer body 210, respectively. Similarly, slit-shaped openings 252a, 243a, 254a, 245a, and 256a extending in the Z-axis direction are formed between the wall portions 252, 243, 254, 245, and 256 and the spacer body 210, respectively. Opening 232a is connected to a groove portion 213 formed in the spacer body 210, and the refrigerant that flows into the groove portion 213 from opening 213a can be discharged to the outside of the spacer 200a (see dashed lines in Figures 4 and 8(b)). Similarly, the other openings are connected to one of the grooves 211 to 219, allowing refrigerant that flows from one of the openings 211a to 219a into one of the grooves 211 to 219 to be discharged to the outside of the spacer 200a.

[0077] [2. Explanation of Effects] As described above, according to the energy storage device 1 of this embodiment, the first spacer wall portion 220A of the first spacer 201 has a first wall portion 223 positioned on one side of the second direction (positive X-axis direction) of the second spacer wall portion 230B of the second spacer 202, and a second wall portion 224 positioned on the other side of the second direction (negative X-axis direction) of the second spacer wall portion 230B. As a result, when the first spacer 201 attempts to move to the other side of the second direction (negative X-axis direction), the first wall portion 223 of the first spacer wall portion 220A contacts the second spacer wall portion 230B, restricting the movement of the first spacer 201 to the other side of the second direction (negative X-axis direction). When the first spacer 201 attempts to move to one side of the second direction (positive X-axis direction), the second wall portion 224 of the first spacer wall portion 220A contacts the second spacer wall portion 230B, restricting the movement of the first spacer 201 to one side of the second direction (positive X-axis direction). In this way, even if vibration or shock is applied to the energy storage device 1 in the second direction (X-axis direction), the movement of the first spacer 201 can be restricted in both directions (one side and the other side in the second direction, both sides in the X-axis direction), thereby improving the vibration resistance or shock resistance of the energy storage device 1.

[0078] The third wall portion 225 sandwiches the second wall portion 224 between the first wall portion 223 and is positioned on one side of the second direction (positive X-axis direction) of the second spacer wall portion 230B. Therefore, the first wall portion 223 and the third wall portion 225 restrict the movement of the first spacer 201 to the other side of the second direction (negative X-axis direction), and the second wall portion 224 restricts the movement of the first spacer 201 to one side of the second direction (positive X-axis direction). The third wall portion 222 sandwiches the first wall portion 223 between the second wall portion 224 and is positioned on the other side of the second direction (negative X-axis direction) of the second spacer wall portion 230B. Therefore, the second wall portion 224 and the third wall portion 222 restrict the movement of the first spacer 201 to one side of the second direction (positive X-axis direction), and the first wall portion 223 restricts the movement of the first spacer 201 to the other side of the second direction (negative X-axis direction). As a result, the first wall portion 223, the second wall portion 224, and the third wall portion 222 or 225 can alternately restrict the movement of the first spacer 201 to one side and the other side (both sides in the X-axis direction) in the second direction, thereby further improving the vibration resistance or shock resistance of the energy storage device 1.

[0079] The third spacer wall portion 230A of the first spacer 201 has a fourth wall portion 233 positioned on the other side of the second direction (X-axis negative direction) of the fourth spacer wall portion 220C of the third spacer 203, and a fifth wall portion 234 positioned on one side of the second direction (X-axis positive direction) of the fourth spacer wall portion 220C. As a result, when the first spacer 201 attempts to move to one side of the second direction (X-axis positive direction), the fourth wall portion 233 of the third spacer wall portion 230A contacts the fourth spacer wall portion 220C of the third spacer 203, restricting the movement of the first spacer 201 to one side of the second direction (X-axis positive direction). When the first spacer 201 attempts to move to the other side of the second direction (negative X-axis direction), the fifth wall portion 234 of the third spacer wall portion 230A contacts the fourth spacer wall portion 220C of the third spacer 203, thereby restricting the movement of the first spacer 201 to the other side of the second direction (negative X-axis direction). In this way, the movement of the first spacer 201 in both directions (both sides in the X-axis direction) can be restricted, even on the other side of the first direction (negative Y-axis direction). Therefore, even if vibration or shock is applied to the energy storage device 1 in the second direction (X-axis direction), the movement of the first spacer 201 can be restricted on both sides (both sides in the Y-axis direction) of the first direction. Thus, the vibration resistance or shock resistance of the energy storage device 1 can be further improved.

[0080] The fifth spacer wall portion 240A of the first spacer 201 has a sixth wall portion 243 positioned on the other side of the second direction (X-axis negative direction) of the sixth spacer wall portion 250B of the second spacer 202, and a seventh wall portion 244 positioned on one side of the second direction (X-axis positive direction) of the sixth spacer wall portion 250B. As a result, when the first spacer 201 attempts to move to one side of the second direction (X-axis positive direction), the sixth wall portion 243 of the fifth spacer wall portion 240A contacts the sixth spacer wall portion 250B of the second spacer 202, thereby restricting the movement of the first spacer 201 to one side of the second direction (X-axis positive direction). When the first spacer 201 attempts to move to one side of the second direction (positive X-axis direction), the seventh wall portion 244 of the fifth spacer wall portion 240A contacts the sixth spacer wall portion 250B of the second spacer 202, thereby restricting the movement of the first spacer 201 to one side of the second direction (positive X-axis direction). In this way, the movement of the first spacer 201 in both directions (one side and the other side of the second direction, both sides in the X-axis direction) can also be restricted on the other side of the second direction (negative X-axis direction). Therefore, even if vibration or shock is applied to the energy storage device 1 in the second direction (X-axis direction), the movement of the first spacer 201 can be restricted on both sides of the second direction (one side and the other side, both sides in the X-axis direction), thereby further improving the vibration resistance or shock resistance of the energy storage device 1.

[0081] The first wall portion 223 of the first spacer wall portion 220A of the first spacer 201 is positioned within a recess (a recess formed by the wall portion 233) that is recessed in the second direction (X-axis direction) formed in the second spacer wall portion 230B of the second spacer 202. As a result, when the first spacer 201 attempts to move in a direction intersecting the second direction (such as the Z-axis direction), the first wall portion 223 contacts the wall of the recess, restricting the movement of the first spacer 201. Therefore, since the movement of the first spacer 201 can be restricted even in a direction intersecting the second direction (such as the Z-axis direction), the vibration resistance or shock resistance of the energy storage device 1 can be further improved.

[0082] The above describes the effect of spacer 200a on some wall sections, but the same effect is achieved on other wall sections as well. Furthermore, the above describes the effect of spacer 200a on some spacer 200a on the energy storage unit 10, but the same effect is achieved on other spacer 200a as well.

[0083] [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.

[0084] In the above embodiment, the spacer 200a is provided with an opening 232a, etc., to discharge refrigerant (air, etc.) to the outside of the spacer 200a from the opening 232a, etc., but the spacer 200a is not limited to being provided with an opening 232a, etc. Figure 9 is a perspective view showing the configuration of the first spacer 204 according to a modified example of this embodiment. Specifically, Figures 9(a) and 9(b) correspond to Figures 4(a) and 4(b). Figure 10 is a perspective view and a cross-sectional view showing the configuration of the first spacer 204 and the second spacer 205 according to a modified example of this embodiment when arranged in the energy storage element 100. Specifically, Figure 10(a) is a perspective view corresponding to Figure 8(a), and Figure 10(b) is a cross-sectional view corresponding to half of Figure 8(b) in the positive X-axis direction.

[0085] As shown in Figure 9, in this modified example, the first spacer 204 has a first spacer wall 220D and a third spacer wall 230D instead of the first spacer wall 220A and third spacer wall 230A that the first spacer 201 in the above embodiment has. The first spacer wall 220D has wall portions 222a, 224a and 226a instead of wall portions 222, 224 and 226 that the first spacer wall 220A has. The third spacer wall 230D has wall portions 233a and 235a instead of wall portions 233 and 235 that the third spacer wall 230A has. In the first spacer 204, there are no openings 232a, 223a, 234a, 225a and 236a between the wall portions 232, 223, 234, 225 and 236 and the spacer body 210. The first spacer 204 further has a flat plate-shaped wall portion 280 that protrudes in the positive X-axis direction from between the first spacer wall portion 220D and the third spacer wall portion 230D and extends in the Z-axis direction.

[0086] The first spacer 204 has a fifth spacer wall (not shown) and a seventh spacer wall 250D instead of the fifth spacer wall 240A and seventh spacer wall 250A that the first spacer 201 in the above embodiment has. Furthermore, the first spacer 204 has a flat plate-shaped wall (not shown) that protrudes in the negative X-axis direction from between the fifth spacer wall and the seventh spacer wall 250D and extends in the Z-axis direction. The first spacer 204, like the first spacer 201, has a shape that is symmetrical with respect to a plane passing through its center and parallel to the YZ plane. Therefore, the configuration of the fifth spacer wall, the seventh spacer wall 250D and its surroundings has a shape that is symmetrical with respect to the first spacer wall 220D, the third spacer wall 230D and its surroundings. For this reason, a detailed explanation of these is omitted. The other configurations of this modified example are the same as in the above embodiment, so a detailed explanation is omitted.

[0087] Wall portions 222a, 224a, 226a, 233a, and 235a are located in the negative X-axis direction more than wall portions 222, 224, 226, 233, and 235 in the above embodiment, and each has ribs 222b, 224b, 226b, 233b, and 235b on its face in the positive X-axis direction. Each of the ribs 222b, 224b, 226b, 233b, and 235b is a projection (projection) that protrudes in the positive X-axis direction from the center of the Z-axis direction of the face in the positive X-axis direction of each of the wall portions 222a, 224a, 226a, 233a, and 235a and extends in the Y-axis direction. The rib 222b of wall portion 222a will be described below, but the same applies to the other ribs.

[0088] As shown in Figure 10, when the first spacer 204 and the second spacer 205 are positioned to sandwich the energy storage element 100, the wall portion 222a of the first spacer wall portion 220D of the first spacer 204 is positioned opposite the wall portion 232 of the second spacer wall portion 230E of the second spacer 205. The second spacer 205 is a spacer with the same shape as the first spacer 204. In other words, the second spacer 205 has spacer wall portions 220E and second spacer wall portions 230E, etc., which have the same shape as the first spacer wall portion 220D and third spacer wall portion 230D, etc., of the first spacer 204.

[0089] As a result, the rib 222b of the wall portion 222a of the first spacer wall portion 220D is positioned to protrude toward the wall portion 232 of the second spacer wall portion 230E. This configuration creates a space (gap) on both sides of the rib 222b in the Z-axis direction between the wall portion 222a of the first spacer wall portion 220D and the wall portion 232 of the second spacer wall portion 230E. Since this space (gap) is connected to the groove portion 213 formed in the spacer body 210 of the second spacer 205, the refrigerant (air, etc.) that flows into the groove portion 213 from the opening 213a passes through the space (gap) and is discharged along the wall portion 280 (see the dashed line in Figures 9 and 10(b)).

[0090] In this modified example, a rib may be provided on the wall portion 232 of the second spacer wall portion 230E in place of, or in addition to, the rib 222b of the wall portion 222a of the first spacer wall portion 220D. In other words, at least one of the wall portion 222a of the first spacer wall portion 220D and the wall portion 232 of the second spacer wall portion 230E facing the wall portion 222a may have a rib that protrudes toward the other. The same applies to the wall portion 223 (first wall portion 223) of the first spacer wall portion 220D. In other words, at least one of the first wall portion 223 of the first spacer wall portion 220D and the wall portion 233a (not shown) of the second spacer wall portion 230E facing the first wall portion 223 may have a rib that protrudes toward the other. The same applies to the other wall portions.

[0091] As described above, the energy storage device 1 according to this modified example can achieve the same effects as the above embodiment. In particular, since ribs are provided on at least one of the first wall portion 223 of the first spacer 204 and the wall portion 233a of the second spacer 205 that faces the first wall portion 223, the gap between the first wall portion 223 and the wall portion 233a can be filled with the ribs. In the case where the energy storage element 100 is cooled with a refrigerant (air, etc.), the ribs can form a flow path for the refrigerant between the first wall portion 223 and the wall portion 233a. Therefore, since it is not necessary to form an opening 232a, etc. in the first spacer 204, etc. as in the above embodiment, the manufacturing of the first spacer 204, etc. is easy (it can be manufactured with a mold with a simple configuration that does not require a sliding structure).

[0092] In the above modified example, the protrusions formed on the wall were referred to as ribs, but instead of forming protrusions on the wall, grooves may be formed on the wall, and the resulting protruding portions may also be referred to as ribs. This also provides the same effects as described above, such as being able to form a flow path for the refrigerant without forming openings 232a, etc., in the first spacer 204, etc.

[0093] (Other variations) 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 or the container lid portion 130 of the container 110.

[0094] In the above embodiment, the spacer 200a is assumed to have spacer wall portions 220 to 270, but it is not limited to having all of these spacer wall portions. The spacer 200a does not have to have spacer wall portion 260, nor does it have to have spacer wall portion 270. In other words, the spacer 200a does not have to be a holder for holding the energy storage element 100. The spacer 200a does not have to have any of the spacer wall portions 220 to 250. In other words, the spacer 200a only needs to have at least one of the spacer wall portions 220 to 250.

[0095] In the above embodiment, the spacer wall portion 220 of the spacer 200a is assumed to have wall portions 221 to 227, but it is not limited to having all of these wall portions. The spacer wall portion 220 does not have to have wall portion 221, nor does it have to have wall portion 227. The spacer wall portion 220 only needs to have two wall portions from wall portions 222 to 226, such as wall portions 223 and 224, which are positioned at different locations in the X-axis direction relative to the spacer wall portion 230 of the adjacent spacer 200a. The same applies to the spacer wall portions 230 to 250.

[0096] In the above embodiment, the wall portions 222 to 226 of the spacer wall portion 220 of spacer 200a are shown to have the same length in the Y-axis direction, but any one of the wall portions 222 to 226 may have a different length. The wall portions 222, 224, and 226 located in the negative X-axis direction of wall portions 223 and 225 may have a shorter Y-axis length than wall portions 223 and 225, or a longer length, or a combination of other lengths. Similarly, the wall portions 232 to 236 of spacer wall portion 230 are shown to have the same length in the Y-axis direction, but any one of the wall portions 232 to 236 may have a different length. The wall portions 233 and 235 located in the negative X-axis direction of wall portions 232, 234, and 236 may have a shorter Y-axis length than wall portions 232, 234, and 236, or a combination of other lengths. The same applies to spacer wall portions 240 and 250.

[0097] In the above embodiment, the positions of the wall portions 222 to 226 of the spacer wall portion 220 of the spacer 200a are alternately different in the X-axis direction, but they may also be the same in the X-axis direction. That is, if the positions of the wall portions 232 to 236 of the spacer wall portion 230 are alternately and significantly different in the X-axis direction, the positions of the wall portions 222 to 226 may be the same in the X-axis direction. Similarly, the positions of the wall portions 222 to 226 of the spacer wall portion 220 may be alternately and significantly different, and the positions of the wall portions 232 to 236 of the spacer wall portion 230 may be the same in the X-axis direction. The same applies to the spacer wall portions 240 and 250.

[0098] 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.

[0099] 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 has the same configuration as spacer 200a. For spacer 200c, the configuration is the same as half of that of spacer 200a in the Y-axis direction.

[0100] 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 one spacer 200 (spacer 200a, 200b, or 200c) is arranged is also possible.

[0101] 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.

[0102] The present invention also includes forms constructed by arbitrarily combining the components of the above embodiments and their variations. [Industrial applicability]

[0103] This invention can be applied to energy storage devices equipped with energy storage elements such as lithium-ion secondary batteries. [Explanation of Symbols]

[0104] 1. Energy storage device 100 energy storage elements 200, 200a, 200b, 200c spacers 201, 204 First spacer 202, 205 Second spacer 203 Third Spacer 210 Spacer body 211, 212, 213, 214, 215, 216, 217, 218, 219 Grooves 211a, 212a, 213a, 214a, 215a, 216a, 217a, 218a, 219a, 223a, 225a, 232a, 234a, 236a, 243a, 245a, 252a, 254a, 256a opening 220, 220B, 220E, 230, 230C, 240, 240B, 250, 250C, 260, 270 Spacer wall section 220A, 220D First spacer wall section 220C Fourth spacer wall section 221, 222a, 224a, 226, 226a, 227, 231, 232, 233a, 235, 235a, 236, 237, 241, 242, 245, 246, 247, 251, 252, 253, 254, 255, 256, 257, 280 Wall section 222, 225 Third wall (wall) 222b, 224b, 226b, 233b, 235b Ribs 223 First wall (wall) 224 Second wall (wall) 230A, 230D Third spacer wall section 230B, 230E Second spacer wall section 233 Fourth wall (wall) 234 Fifth wall (wall) 240A Fifth Spacer Wall Section 240C Eighth Spacer Wall Section 243 Sixth wall (wall) 244 Seventh wall (wall) 250A, 250D Seventh Spacer Wall Section 250B Sixth Spacer Wall Section 300 cases 310 Case Body 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 toward the second spacer from one end in a second direction intersecting the first direction, The second spacer has a second spacer wall portion that protrudes toward the first spacer from one end in the second direction, The first spacer wall portion is, The first wall portion is located on one side of the second direction of the second spacer wall portion, It has a second wall portion that is aligned with the first wall portion in a third direction intersecting the first and second directions, and is located on the other side of the second direction of the second spacer wall portion, The other side of the second wall portion in the second direction is positioned on the other side of the second direction than the other side of the first wall portion in the second direction, which is located in the third direction of that surface. Energy storage device.

2. The first spacer wall portion further includes a third wall portion positioned on one side of the second spacer wall portion in the second direction, where the second wall portion is sandwiched between the first spacer wall portion and the third wall portion, and at least one of the third wall portions positioned on the other side of the second spacer wall portion in the second direction, where the first spacer wall portion is sandwiched between the second spacer wall portion and the third wall portion. The energy storage device according to claim 1.

3. The aforementioned energy storage device further comprises a third spacer, The first spacer is positioned between the second spacer and the third spacer. The first spacer has a third spacer wall portion that protrudes toward the third spacer from one end in the second direction, The third spacer has a fourth spacer wall portion that protrudes toward the first spacer from one end in the second direction, The third spacer wall portion is, The fourth wall portion is located on the other side of the fourth spacer wall portion in the second direction, It has a fifth wall portion that is aligned with the fourth wall portion in the third direction and is positioned on one side of the fourth spacer wall portion in the second direction. The energy storage device according to claim 1 or 2.

4. The first spacer has a fifth spacer wall portion that protrudes toward the second spacer from the other end in the second direction, The second spacer has a sixth spacer wall portion that protrudes toward the first spacer from the other end in the second direction, The aforementioned fifth spacer wall portion is, The sixth wall portion is located on the other side of the sixth spacer wall portion in the second direction, It has a seventh wall portion that is aligned with the sixth wall portion in the third direction and is located on one side of the sixth spacer wall portion in the second direction. The energy storage device according to any one of claims 1 to 3.

5. A recess is formed in the second spacer wall portion at a position facing the first wall portion, with the recess extending toward the other side in the second direction. The first wall portion is positioned within the recess. The energy storage device according to any one of claims 1 to 4.

6. At least one of the first wall portion and the wall portion of the second spacer wall portion facing the first wall portion has a rib that protrudes toward the other. The energy storage device according to any one of claims 1 to 5.

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