Energy storage device

Abstract

Provided is a power storage device (10) comprising a power storage element (100) and a side plate (500) arranged in a first direction of the power storage element (100), wherein: the power storage element (100) or a spacer (200) arranged in a second direction intersecting the first direction of the power storage element (100) has a first surface (230a) facing the side plate (500) in a third direction intersecting the first direction and the second direction; the side plate (500) has a second surface (620a) facing the first surface (230a) in the third direction; and formed on at least one of the first surface (230a) and the second surface (620a) is a projection (231) projecting toward the other thereof.

Description

Technical Field

[0001] The present invention relates to a power storage device including a power storage element and a side plate.

Background Art

[0002] Conventionally, in a power storage device including a power storage element and a side plate, a configuration in which one of the power storage element or a spacer on the side of the power storage element and the side plate has a protrusion protruding toward the other is known. Patent Document 1 discloses a power supply device (power storage device) in which an insulating spacer on the side of a battery cell (power storage element) has a pressing region (protrusion) protruding toward a side plate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the power storage device having the above conventional configuration, when the contact area between the power storage element or the spacer and the side plate is increased, the vibration resistance or shock resistance performance (load resistance performance) can be improved. Therefore, in the conventional power storage device disclosed in Patent Document 1, it is desirable to increase the contact area between the protrusion (pressing region) of the spacer and the side plate. However, when assembling the side plate to the power storage element, since the side plate is assembled while contacting the protrusion, if the contact area between the protrusion and the side plate is large, the assembly load due to the protrusion becomes large, and there is a risk that the assembly of the side plate to the power storage element becomes difficult. Similarly, when the protrusion is formed on the side plate, the inventor has found that if the contact area between the protrusion and the power storage element or the spacer is large, the assembly load due to the protrusion becomes large, and there is a risk that the assembly of the side plate to the power storage element becomes difficult.

[0005] The present invention aims to provide an energy storage device that facilitates the assembly of side plates to energy storage elements. [Means for solving the problem]

[0006] An energy storage device according to one aspect of the present invention is an energy storage device comprising an energy storage element and a side plate disposed in a first direction of the energy storage element, wherein the energy storage element, or a spacer disposed in a second direction intersecting the first direction of the energy storage element, has a first surface facing the side plate in a third direction intersecting the first and second directions, the side plate has a second surface facing the first surface in the third direction, and at least one of the first surface and the second surface has a projection that protrudes toward the other. [Effects of the Invention]

[0007] According to the energy storage device of the present invention, the assembly of the side plate to the energy storage element can be easily performed. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view showing the external appearance of an energy storage device according to an embodiment. [Figure 2] Figure 2 is an exploded perspective view showing the components of the energy storage device according to the embodiment when it is disassembled. [Figure 3] Figure 3 is a perspective view showing the configuration of an energy storage element according to an embodiment. [Figure 4] Figure 4 shows a perspective view, a top view, and a front view illustrating the configuration of the spacer according to the embodiment. [Figure 5] Figure 5 is a cross-sectional view showing the positional relationship between the spacer, the energy storage element, and the side plate according to the embodiment. [Figure 6] Figure 6 is a cross-sectional view showing the process of assembling a side plate to the energy storage element and spacer according to the embodiment. [Figure 7A]Figure 7A is a front view showing the configuration of a spacer according to a modified example 1 of the embodiment. [Figure 7B] Figure 7B is a front view showing the configuration of a spacer according to a modified example 1 of the embodiment. [Figure 7C] Figure 7C is a front view showing the configuration of a spacer according to a modified example 1 of the embodiment. [Figure 8] Figure 8 is a front view and a perspective view showing the configuration of a side plate according to a modified example 2 of the embodiment. [Modes for carrying out the invention]

[0009] An energy storage device according to one aspect of the present invention is an energy storage device comprising an energy storage element and a side plate disposed in a first direction of the energy storage element, wherein the energy storage element, or a spacer disposed in a second direction intersecting the first direction of the energy storage element, has a first surface facing the side plate in a third direction intersecting the first and second directions, the side plate has a second surface facing the first surface in the third direction, and at least one of the first surface and the second surface has a projection that protrudes toward the other.

[0010] This makes it easier to assemble the side plates to the energy storage elements.

[0011] The projection may have an inclined surface that slopes away from the side plate in the first direction as it moves away from the energy storage element in the third direction.

[0012] According to this, since the protrusion has an inclined surface, when assembling the side plate to the energy storage element from the first direction, the side plate is assembled to the energy storage element from the first direction along the inclined surface. This makes it even easier to assemble the side plate to the energy storage element.

[0013] The side plate may have an insulating member on which the protrusion is formed.

[0014] According to this, the side plate has an insulating member, and a protrusion is formed on the insulating member. Thereby, a configuration that facilitates the assembly of the side plate to the power storage element can be realized.

[0015] It is also possible that a plurality of protrusions protruding toward the other are formed on at least one of the first surface and the second surface.

[0016] According to this, in the power storage device, the power storage element or the spacer, and the side plate of the power storage element in the first direction have first and second surfaces facing each other in the third direction, and on at least one of the first and second surfaces, a plurality of protrusions protruding toward the other are formed. Thereby, when assembling the side plate to the power storage element from the first direction, the contact area of the other member with respect to one protrusion decreases. Therefore, the assembly load due to the protrusions can be reduced, and the assembly of the side plate to the power storage element can be made easier.

[0017] It is also possible that the plurality of protrusions are arranged at different positions in the first direction.

[0018] According to this, the plurality of protrusions formed on at least one of the first and second surfaces of the power storage element or the spacer and the side plate are arranged at different positions in the first direction. Thereby, when assembling the side plate to the power storage element from the first direction, in the first direction, the plurality of protrusions are sequentially contacted. Therefore, since the assembly load due to the protrusions can be divided into a plurality of stages, the assembly load due to the protrusions can be reduced, and the assembly of the side plate to the power storage element can be made easier.

[0019] It is also possible that the plurality of protrusions are arranged at non-overlapping positions in the first direction.

[0020] According to this, the multiple protrusions formed on at least one of the first and second surfaces of the energy storage element or spacer and side plate are arranged in positions that do not overlap in the first direction. By arranging the multiple protrusions in positions that do not overlap in the first direction, when assembling the side plate to the energy storage element from the first direction, one protrusion is contacted before the next protrusion is contacted in the first direction. This further reduces the assembly load caused by the protrusions, making it even easier to assemble the side plate to the energy storage element.

[0021] At least one of the plurality of protrusions may be positioned so as to overlap with a part of the energy storage element when viewed from the third direction.

[0022] According to this design, at least one of the multiple protrusions is positioned to overlap with a portion of the energy storage element when viewed from a third direction, allowing the side plate to more firmly hold the energy storage element in that third direction. This facilitates the assembly of the side plate to the energy storage element while improving the vibration resistance or shock resistance (load-bearing capacity) of the energy storage device.

[0023] At least one of the plurality of protrusions may have an inclined surface that is inclined in the direction away from the side plate in the first direction as it moves away from the energy storage element in the third direction.

[0024] According to this, since at least one of the multiple protrusions has an inclined surface, when assembling the side plate to the energy storage element from the first direction, the side plate is assembled to the energy storage element from the first direction along the inclined surface. This makes it even easier to assemble the side plate to the energy storage element.

[0025] The side plate may have an insulating member on which the plurality of protrusions are formed.

[0026] According to this design, the side plate has an insulating material, and multiple protrusions are formed on the insulating material. This makes it possible to realize a configuration that facilitates the assembly of the side plate to the energy storage element.

[0027] The present invention can be realized not only as such an energy storage device, but also as a combination of an energy storage element and a side plate, or as a combination of an energy storage element, a spacer and a side plate.

[0028] 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.

[0029] In the following description and drawings, the direction of alignment of a pair of electrode terminals in one energy storage element, the direction of opposition between a pair of short sides in the container of one energy storage element, or the direction of alignment of a pair of side plates are defined as the first direction and the X-axis direction. The direction of alignment of multiple energy storage elements, multiple spacers, a pair of end plates, an energy storage element, a spacer, and an end plate, the direction of opposition between a pair of long sides in the container of one energy storage element, or the thickness direction of an energy storage element, spacer, or end plate are defined as the second direction and the Y-axis direction. The direction of alignment between the container body and the lid of an energy storage element container, or the vertical direction, is defined as the third direction and the Z-axis direction. These X-axis, Y-axis, and Z-axis directions intersect (orthogonal in this embodiment) with each other. 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.

[0030] In the following description, the X-axis positive direction refers to the direction of the X-axis arrow, and the X-axis negative direction refers to the direction opposite to the X-axis positive direction. The same applies to the Y-axis and Z-axis directions. In this embodiment, the X-axis positive direction indicates the direction to one side (right) when viewing the energy storage device from the direction in which the energy storage elements are arranged (Y-axis direction). The X-axis negative direction indicates the direction to the other side (left) when viewing the energy storage device from the direction in which the energy storage elements are arranged (Y-axis direction). The Y-axis positive direction indicates the direction towards the back when viewing the energy storage device from the direction in which the energy storage elements are arranged (Y-axis direction). The Y-axis negative direction indicates the direction towards the front when viewing the energy storage device from the direction in which the energy storage elements are arranged (Y-axis direction). The Z-axis positive direction indicates the direction in which the terminals of the energy storage elements are arranged when viewing the energy storage device from the direction in which the energy storage elements are arranged (Y-axis direction). The Z-axis negative direction indicates the direction opposite to the direction in which the terminals of the energy storage elements are arranged when viewing the energy storage device from the direction in which the energy storage elements are arranged (Y-axis direction). Furthermore, expressions indicating relative direction or orientation, such as parallel and orthogonal, include cases where the direction or orientation is not strictly accurate. Two directions being orthogonal does not only mean that the two directions are perfectly orthogonal, but also that they are substantially orthogonal, meaning they may differ by a few percent.

[0031] (Embodiment) [1. General description of the energy storage device 10] First, a general description of the energy storage device 10 in this embodiment will be given. Figure 1 is a perspective view showing the external appearance of the energy storage device 10 according to this embodiment. Figure 2 is an exploded perspective view showing the individual components when the energy storage device 10 according to this embodiment is disassembled.

[0032] The energy storage device 10 is a device that can charge electricity from an external source and discharge electricity to the outside, and in this embodiment, it has a substantially rectangular parallelepiped shape. The energy storage device 10 is a battery module (battery pack) used for power storage or power supply purposes. Specifically, the energy storage device 10 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 gasoline automobiles. Examples of railway vehicles for electric railways include electric trains, monorails, linear motor cars, and hybrid trains equipped with both diesel engines and electric motors. The energy storage device 10 can also be used as a stationary battery for household or commercial use.

[0033] As shown in Figures 1 and 2, the energy storage device 10 comprises a plurality of energy storage elements 100, a plurality of spacers 200 and 300, a pair of end plates 400, and a pair of side plates 500, the side plates 500 having insulators 600. The energy storage device 10 also includes busbars that connect the energy storage elements 100 in series or parallel, but these are not shown or described. In addition to the above components, the energy storage device 10 may also include a busbar frame for positioning the busbars, an exterior body housing the above components, external terminals connected to external busbars, etc., and electrical equipment such as circuit boards, fuses, relays, and connectors for monitoring or controlling the charging and discharging states of the energy storage elements 100.

[0034] 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), and in this embodiment, eight energy storage elements 100 are arranged in the Y-axis direction. The size, shape, and number of energy storage elements 100 arranged are not limited, and only one energy storage element 100 may be arranged. The energy storage element 100 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, or it may be a capacitor. The energy storage element 100 may be a primary battery. The energy storage element 100 may be a battery using a solid electrolyte. The energy storage element 100 may be a pouch-type energy storage element. A detailed explanation of the configuration of the energy storage element 100 will be given later.

[0035] Spacers 200 and 300 are flat, rectangular members positioned in the Y-axis direction (second direction) of the energy storage element 100, electrically insulating the energy storage element 100 from other members. In other words, spacers 200 and 300 are positioned in the positive or negative Y-axis direction of the energy storage element 100, electrically insulating the energy storage elements 100 from each other, or from the energy storage elements 100 to the end plate 400. Spacers 200 and 300 are formed from electrically 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), ABS resin, or composite materials thereof; electrically insulating coated metals; or heat insulating materials such as damper material.

[0036] The spacer 200 is a flat, rectangular spacer (intermediate spacer) parallel to the XZ plane, placed between two adjacent energy storage elements 100 to electrically insulate them from each other. Specifically, the spacer 200 is positioned between the long sides 111 of the containers 110 of the two energy storage elements 100, facing and in contact with the long sides 111. In this embodiment, seven spacers 200 are arranged alternately with eight energy storage elements 100 in the Y-axis direction. However, if the number of energy storage elements 100 is other than eight, the number of spacers 200 is appropriately changed according to the number of energy storage elements 100. When the energy storage elements 100 are connected in parallel, spacers 200 do not need to be placed between the parallel-connected energy storage elements 100. A detailed explanation of the configuration of the spacer 200 will be given later.

[0037] The spacer 300 is a flat, rectangular spacer (end spacer) parallel to the XZ plane, positioned between the end energy storage element 100 and the end plate 400, electrically insulating the end energy storage element 100 and the end plate 400. Two spacers 300 are positioned between the energy storage elements 100 at both ends in the Y-axis direction and the pair of end plates 400. Specifically, the spacer 300 is positioned between the long side surface 111 of the container 110 of the energy storage element 100 at the Y-axis end and the Y-axis direction surface of the end plate 400, facing and in contact with the long side surface 111 and the surface of the end plate 400.

[0038] In this embodiment, the spacer 300 has a shape similar to that of the spacer 200 cut in half along the Y-axis. That is, the spacer 300 located in the positive Y-axis direction has a shape similar to the portion on the negative Y-axis side when the spacer 200 is cut in half along the Y-axis. The spacer 300 located in the negative Y-axis direction has a shape similar to the portion on the positive Y-axis side when the spacer 200 is cut in half along the Y-axis. For this reason, the detailed configuration of the spacer 300 is the same as the detailed configuration of the spacer 200 described later, and its explanation is omitted. In Figure 2, the spacer 300 does not show a projection corresponding to the projection 231 of the spacer 200 described later, but the spacer 300 may have a projection similar to the projection 231.

[0039] The end plate 400 and the side plate 500 are restraining members that compress (restrain) the energy storage elements 100 from the outside in the direction of alignment of the multiple energy storage elements 100 (Y-axis direction). In other words, the end plate 400 and the side plate 500 sandwich the multiple energy storage elements 100 from both sides in the direction of alignment, thereby compressing (restraining) each energy storage element 100 included in the multiple energy storage elements 100 from both sides in the direction of alignment.

[0040] The end plates 400 are plate-shaped (flat block-shaped) restraining members (clamping members) that are positioned on both sides in the Y-axis direction of the multiple energy storage elements 100 and the multiple spacers 200 and 300, and hold the multiple energy storage elements 100 etc. by sandwiching them from both sides in the direction of their arrangement (Y-axis direction). In other words, a pair of end plates 400 are positioned to sandwich the multiple energy storage elements 100 and the multiple spacers 200 and 300 in the Y-axis direction (the stacking direction of the electrode plates of the electrode bodies of the energy storage elements 100), and restrain them. The end plates 400 are made of a metal member such as steel or stainless steel from the viewpoint of ensuring strength, but the material is not particularly limited. The end plates 400 may be made of a highly strong electrically insulating member, or a metal member may be treated with an insulating coating.

[0041] The side plate 500 is a plate-shaped, elongated restraining member (restraining bar) positioned in the X-axis direction (first direction) of the multiple energy storage elements 100 and the multiple spacers 200 and 300. Specifically, the side plate 500 is attached at both ends to a pair of end plates 400, and by connecting the pair of end plates 400, it restrains the multiple energy storage elements 100 and the multiple spacers 200 and 300. In other words, the side plate 500 is positioned extending in the Y-axis direction so as to straddle the multiple energy storage elements 100 and the multiple spacers 200 and 300, and applies a restraining force to the multiple energy storage elements 100, etc. in the direction of their alignment (Y-axis direction).

[0042] In this embodiment, a pair of side plates 500 are arranged on both sides in the X-axis direction of a plurality of energy storage elements 100 and a plurality of spacers 200 and 300. Each of the pair of side plates 500 is attached to the X-axis ends of a pair of end plates 400 at both ends in the Y-axis direction. As a result, the pair of side plates 500, together with the pair of end plates 400, sandwich and restrain the plurality of energy storage elements 100, etc., from both sides in the X-axis direction and both sides in the Y-axis direction. Specifically, the side plates 500 are connected (joined) to the end plates 400 by a plurality of (three in this embodiment) connecting members 500a arranged in the Z-axis direction. In this embodiment, the connecting members 500a are bolts (screws) and are fastened by screwing into the female threaded portion formed on the end plate 400. The connection (joining) of the side plates 500 to the end plates 400 is not limited to fixing with bolts (screws), but may also be joined by welding or adhesive.

[0043] As described above, the side plate 500 has an insulator 600 on its inner side (the side with the energy storage element 100). The insulator 600 is a plate-shaped, elongated insulating member that is positioned on both sides in the X-axis direction of the multiple energy storage elements 100 and the multiple spacers 200 and 300, and extends in the Y-axis direction. In other words, the insulator 600 is positioned between the multiple energy storage elements 100 and the side plate 500 (excluding the insulator 600) so as to straddle the multiple energy storage elements 100 and the multiple spacers 200 and 300. As a result, the insulator 600 electrically insulates the multiple energy storage elements 100 from the side plate 500 (excluding the insulator 600). The side plate 500 (excluding the insulator 600), like the end plate 400, is made of a metal material such as steel or stainless steel for the purpose of ensuring strength, but its material is not particularly limited. The side plate 500 (excluding the insulator 600) may be made of a high-strength electrically insulating material, or it may be made of a metal material that has been insulated. The insulator 600 may be made of any material that has electrical insulating properties, and can be made of any electrically insulating material that can be used for the spacers 200 and 300.

[0044] [2. Description of the energy storage element 100] Next, the configuration of the energy storage element 100 will be described in detail. Figure 3 is a perspective view showing the configuration of the energy storage element 100 according to this embodiment. Specifically, Figure 3 shows an enlarged view of the external appearance of one of the multiple energy storage elements 100 shown in Figure 2. Since all of these multiple energy storage elements 100 have the same configuration, the configuration of one energy storage element 100 will be described in detail below.

[0045] As shown in Figure 3, the energy storage element 100 comprises a container 110, a pair of electrode terminals 140 (positive and negative sides), and an upper gasket 150. Inside the container 110 are a lower gasket, electrode bodies, a pair of current collectors (positive and negative sides), and an electrolyte (non-aqueous electrolyte), 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.

[0046] In addition to the above-mentioned components, the energy storage element 100 may also have spacers positioned to the side or below the electrode body, and an insulating film that encloses the electrode body, etc. Furthermore, an insulating film (such as a shrink tube) covering the outer surface of the container 110 may be placed around the container 110. The material of the insulating film is not particularly limited as long as it can ensure the electrical insulation required for the energy storage element 100. Examples of materials for the insulating film include electrically insulating resins such as PC, PP, PE, PPS, PET, PBT, or ABS resin, epoxy resin, Kapton, Teflon (registered trademark), silicon, polyisoprene, and polyvinyl chloride.

[0047] The container 110 is a rectangular parallelepiped (square or box-shaped) case having a container body 120 with an opening and a 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 lid 130 is a rectangular plate-shaped member that constitutes the lid of the container 110, and is arranged extending in the X-axis direction on the Z-axis positive side of the container body 120. The container 110 (lid 130) may be provided with a gas discharge valve to release pressure when the pressure inside the container 110 rises excessively, and an injection part for injecting electrolyte into the container 110. The material of the container 110 (container body 120 and lid 130) is not particularly limited, and weldable (joinable) metals such as stainless steel, aluminum, aluminum alloy, iron, and plated steel sheet can be used. Resin can also be used as the material for the container 110 (container body 120 and lid 130).

[0048] The container 110 has a structure in which, after the electrode body and the like are housed inside the container body 120, the container body 120 and the lid 130 are joined by welding or the like to seal the inside. 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 or 300 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 side plates 500 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 located adjacent to the long side surface 111 and the short side surface 112.

[0049] The electrode terminals 140 are terminal members (positive and negative electrode terminals) of the energy storage element 100, which is placed on the cover 130, and 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, or the like.

[0050] 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.

[0051] The current collector is a conductive member (positive electrode current collector and negative electrode current collector) that is electrically connected to the electrode terminal 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, 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.

[0052] The upper gasket 150 is positioned between the cover 130 and the electrode terminal 140, electrically insulating and sealing the space between the cover 130 and the electrode terminal 140. The lower gasket is positioned between the cover 130 and the current collector, electrically insulating and sealing the space between the cover 130 and the current collector. The upper gasket 150 and the lower gasket may be made of any material that has electrical insulating properties.

[0053] [3. Explanation of Spacer 200] Next, the configuration of the spacer 200 will be described in detail. Figure 4 is a perspective view, a top view, and a front view showing the configuration of the spacer 200 according to this embodiment. Specifically, Figure 4(a) is a perspective view showing an enlarged view of the appearance of one of the multiple spacers 200 shown in Figure 2. Figure 4(b) is a top view showing an enlarged view of the configuration of the X-axis negative projection 231 (231a, 231b) and its surrounding area of ​​the spacer 200 shown in Figure 4(a), as viewed from above (Z-axis positive direction). In Figure 4(b), the containers 110 of the two energy storage elements 100, when the two energy storage elements 100 are arranged on both sides of the spacer 200 in the Y-axis direction, are also shown by dashed lines. Figure 4(c) is an enlarged front view showing the configuration of the X-axis negative projection 231 (231a, 231b) and its surrounding area of ​​the spacer 200 shown in Figure 4(a), as viewed from the front (Y-axis negative direction).

[0054] As shown in Figure 4, the spacer 200 has a similar shape at both ends in the X-axis direction. In other words, the spacer 200 has a shape that is rotationally symmetric when rotated 180° around an axis passing through the center and parallel to the Z-axis direction. A rotationally symmetric shape is preferable because it allows assembly work to be performed without considering the orientation of the spacer. The spacer 200 has a spacer body portion 210, a pair of spacer side wall portions 220, a pair of spacer upper wall portions 230, and a pair of spacer bottom wall portions 240.

[0055] The spacer body portion 210 is a flat, rectangular part that constitutes the body of the spacer 200 and is arranged parallel to the XZ plane. In this embodiment, the spacer body portion 210 is positioned facing the long side portion 111 in the Y-axis direction and in contact with the long side portion 111, so as to cover the entire surface of the long side portion 111 of the container 110 of the energy storage element 100 in the Y-axis positive or Y-axis negative direction of the energy storage element 100.

[0056] The spacer sidewall portion 220 is a flat, rectangular portion that protrudes in the Y-axis direction from the X-axis end of the spacer body portion 210 and extends in the Z-axis direction, and is arranged parallel to the YZ plane. Specifically, a pair of spacer sidewall portions 220 are arranged at both ends of the spacer 200 in the X-axis direction, protruding on both sides in the Y-axis direction from both ends of the spacer body portion 210 in the X-axis direction and extending in the Z-axis direction. In this embodiment, the spacer sidewall portion 220 is arranged along the short side 112 of the container 110 of the energy storage element 100 (see Figure 5). More specifically, the spacer sidewall portion 220 is arranged on both sides of the energy storage element 100 in the X-axis direction, facing the short side 112 in the X-axis direction, so as to cover half of the short side 112 of the container 110 on the Y-axis positive side or the Y-axis negative side. As a result, the entire short side surface 112 of the container 110 of the energy storage element 100 is covered by the spacer side walls 220 of the two spacers 200 that sandwich the energy storage element 100 in the Y-axis direction.

[0057] The spacer bottom wall portion 240 is a flat, rectangular portion that protrudes in the Y-axis direction from the Z-axis negative end of the spacer body portion 210 and is arranged parallel to the XY plane. Specifically, a pair of spacer bottom wall portions 240 are arranged at both ends of the spacer 200 in the X-axis direction, protruding in both directions in the Y-axis direction from both ends of the Z-axis negative end of the spacer body portion 210. In this embodiment, the spacer bottom wall portion 240 is arranged along the bottom surface 113 of the container 110 of the energy storage element 100 on the Z-axis negative side (see Figure 5). More specifically, the spacer bottom wall portion 240 is arranged opposite the bottom surface 113 in the Z-axis direction at both ends of the energy storage element 100 in the X-axis direction, so as to cover half of the bottom surface 113 of the container 110 on the Y-axis positive side or the Y-axis negative side.

[0058] The spacer upper wall portion 230 is a flat, rectangular portion that protrudes in the Y-axis direction from the Z-axis positive end of the spacer body portion 210 and is arranged parallel to the XY plane. Specifically, a pair of spacer upper wall portions 230 are arranged at both ends of the spacer 200 in the X-axis direction, protruding in both directions in the Y-axis direction from both ends of the Z-axis positive end of the spacer body portion 210. In this embodiment, the spacer upper wall portion 230 is arranged along the lid 130 of the container 110 of the energy storage element 100 on the Z-axis positive side (see Figure 5). More specifically, the spacer upper wall portion 230 is arranged opposite the lid 130 in the Z-axis direction at both ends of the energy storage element 100 in the X-axis direction, so as to cover half of the lid 130 of the container 110 on the Y-axis positive side or the Y-axis negative side.

[0059] The upper wall portion 230 of the spacer has a first surface 230a which is a single continuous surface (a plane in this embodiment) facing the positive Z-axis direction, and a plurality of protrusions 231 projecting in the positive Z-axis direction are formed on the first surface 230a. As described above, the spacer 200 has a shape that is rotationally symmetric when rotated 180° around an axis passing through the center position and parallel to the Z-axis direction, so the shapes of the pair of upper wall portions 230 of the spacer coincide when rotated 180° around that axis. For this reason, the following description will focus on the configuration of the upper wall portion 230 of the pair of upper wall portions 230 facing the negative X-axis direction, and the description of the configuration of the upper wall portion 230 of the spacer in the positive X-axis direction will be simplified or omitted.

[0060] In addition to Figure 4(a), as shown in Figures 4(b) and 4(c), the upper wall portion 230 of the spacer has a plurality of protrusions 231 projecting in the positive Z-axis direction from the first surface 230a. In this embodiment, the upper wall portion 230 of the spacer has two protrusions 231a and 231b as the plurality of protrusions 231.

[0061] The protrusions 231 (231a, 231b) are ribs shaped to divide the sphere into four equal parts. Specifically, the protrusions 231 have shapes corresponding to the portions located in the negative X-axis direction and positive Z-axis direction when the sphere is cut by planes passing through its center and parallel to the XY plane and the YZ plane. As a result, the protrusions 231 have a semicircular shape where the negative X-axis direction is an arc when viewed from the positive Z-axis direction, and a sector with a central angle of 90° where the negative X-axis direction and positive Z-axis direction are arcs when viewed from the negative Y-axis direction. In other words, the protrusions 231 are elongated in the Y-axis direction and have a shape where the plane in the negative X-axis direction is inclined.

[0062] Specifically, the projection 231 has a curved inclined surface 231c that slopes in the X-axis direction as it moves in the Z-axis direction (see Figure 4(c)). In this embodiment, the energy storage element 100 is positioned in the Z-axis direction of the projection 231, and the side plate 500 is positioned in the X-axis direction of the projection 231 (see Figure 5, etc.). Therefore, at least one of the multiple projections 231 has an inclined surface 231c that slopes in the direction away from the side plate 500 in the X-axis direction (first direction) as it moves away from the energy storage element 100 in the Z-axis direction (third direction). In this embodiment, all projections 231 (231a and 231b) have an inclined surface 231c.

[0063] The multiple protrusions 231 (two protrusions 231a and 231b) are positioned at different locations in the X-axis direction (first direction). In other words, the multiple protrusions 231 are positioned at offset locations in the X-axis direction (first direction). Specifically, the multiple protrusions 231 (two protrusions 231a and 231b) are positioned at locations that do not overlap in the X-axis direction (first direction). In other words, the multiple protrusions 231 are positioned at spaced-out locations in the X-axis direction (first direction). Furthermore, the multiple protrusions 231 (two protrusions 231a and 231b) are also positioned at different locations in the Y-axis direction (second direction). In other words, the multiple protrusions 231 are positioned at offset locations in the Y-axis direction (second direction). Specifically, the multiple protrusions 231 (two protrusions 231a and 231b) are positioned at locations that do not overlap in the Y-axis direction (second direction). In other words, the multiple protrusions 231 are positioned at spaced-out locations in the Y-axis direction (second direction). The multiple protrusions 231 (two protrusions 231a and 231b) are positioned at the same location in the Z-axis direction (third direction).

[0064] In this embodiment, on the upper wall portion 230 of the spacer in the negative X-axis direction, the projection 231b is positioned in the positive X-axis direction and the negative Y-axis direction more than the projection 231a. On the upper wall portion 230 of the spacer in the positive X-axis direction, the projection 231b is positioned in the negative X-axis direction and the positive Y-axis direction more than the projection 231a. In this way, multiple projections 231 (two projections 231a and 231b) are positioned at different locations in the X-axis direction (first direction) and at non-overlapping locations in the Y-axis direction, so that multiple projections 231 can be easily formed during the manufacturing of the spacer 200.

[0065] At least one of the multiple protrusions 231 is positioned so as to overlap with a portion of the energy storage element 100 when viewed from the Z-axis direction (third direction). In other words, at least one protrusion 231 is positioned directly above the energy storage element 100. Specifically, as shown in Figure 4(b), all of the protrusions 231 (both the two protrusions 231a and 231b) are positioned so as to overlap with a portion of the energy storage element 100 when viewed from the Z-axis direction. In this embodiment, both of the two protrusions 231a and 231b are positioned so as to overlap with the energy storage element 100 when viewed from the Z-axis direction (third direction). It is also possible that only a portion of the protrusion 231a or only a portion of the protrusion 231b overlaps with the energy storage element 100 when viewed from the Z-axis direction (third direction).

[0066] [4. Explanation of the positional relationship between the spacer 200, the energy storage element 100, and the side plate 500] Next, the positional relationship between the spacer 200, the energy storage element 100, and the side plate 500 will be described in detail. Figure 5 is a cross-sectional view showing the positional relationship between the spacer 200, the energy storage element 100, and the side plate 500 according to this embodiment. Specifically, Figure 5(a) is a cross-sectional view showing the energy storage device 10 shown in Figure 1 when it is cut by a plane passing through the VV line and parallel to the XZ plane. Figure 5(b) is an enlarged cross-sectional view showing the X-axis negative projection 231 and its surrounding configuration on the spacer 200 shown in Figure 5(a). Figure 6 is a cross-sectional view showing the process of assembling the side plate 500 to the energy storage element 100 and spacer 200 according to this embodiment. Specifically, Figure 6 corresponds to Figure 5(b), where Figure 6(a) shows the configuration before assembling the side plate 500 to the energy storage element 100 and spacer 200, Figure 6(b) shows the configuration during assembly, and Figure 6(c) shows the configuration after assembly.

[0067] As described above, the side plate 500 has an insulator 600, but as shown in Figures 2 and 5, the portion of the side plate 500 excluding the insulator 600 has a plate body portion 510, a plate upper wall portion 520, and a plate bottom wall portion 530. The insulator 600 has an insulator body portion 610, an insulator upper wall portion 620, and an insulator bottom wall portion 630. Since the pair of side plates 500 (insulators 600) have similar configurations, the following description will focus on the side plate 500 (insulator 600) in the negative X-axis direction, and the description of the side plate 500 (insulator 600) in the positive X-axis direction will be simplified or omitted.

[0068] The plate body portion 510 is a plate-shaped and rectangular portion that is positioned in the negative X-axis direction of the insulator body portion 610 and extends in the Y-axis direction, parallel to the YZ plane. The plate body portion 510 is positioned in contact with the insulator body portion 610 in the X-axis direction. The plate upper wall portion 520 is a long, plate-shaped portion that protrudes in the positive X-axis direction from the Z-axis positive end of the plate body portion 510 and extends in the Y-axis direction. The plate upper wall portion 520 is positioned inserted into and fitted into the insulator upper wall portion 620 from the negative X-axis direction. The plate bottom wall portion 530 is a long, plate-shaped portion that protrudes in the positive X-axis direction from the Z-axis negative end of the plate body portion 510 and extends in the Y-axis direction. The plate bottom wall portion 530 is positioned in contact with the insulator bottom wall portion 630 in the Z-axis direction, in the Z-axis negative direction of the insulator bottom wall portion 630.

[0069] The insulator body portion 610 is a plate-shaped and rectangular portion parallel to the YZ plane, positioned in the negative X-axis direction of the multiple energy storage elements 100 and the multiple spacers 200 and 300, and extending in the Y-axis direction. The insulator body portion 610 is positioned in contact with the multiple spacers 200 (spacer side wall portion 220) and 300 in the X-axis direction. The insulator bottom wall portion 630 is a long, plate-shaped portion that protrudes in the positive X-axis direction from the end of the insulator body portion 610 in the negative Z-axis direction and extends in the Y-axis direction. The insulator bottom wall portion 630 is positioned in contact with the multiple spacers 200 (spacer bottom wall portion 240) and 300 in the Z-axis direction of the multiple energy storage elements 100 and the multiple spacers 200 and 300.

[0070] The insulator upper wall portion 620 is a long, plate-like portion that is positioned in the Z-axis positive direction of the multiple energy storage elements 100 and the multiple spacers 200 and 300, and extends in the Y-axis direction. The insulator upper wall portion 620 protrudes in the X-axis positive direction from the Z-axis positive end of the insulator body portion 610, bends in the Z-axis positive direction, and bends in the X-axis negative direction, giving it a C-shape when viewed from the Y-axis positive direction. As a result, a recess is formed in the insulator upper wall portion 620 that is recessed in the X-axis positive direction, and the plate upper wall portion 520 is inserted into and fitted into this recess. The insulator upper wall portion 620 is positioned in contact with the multiple protrusions 231 formed on the spacer upper wall portion 230 of the multiple spacers 200 in the Z-axis direction.

[0071] Specifically, the upper wall portion 620 of the insulator has a second surface 620a, which is a continuous surface (a plane in this embodiment) facing the negative Z-axis direction. The second surface 620a is the surface that faces the first surface 230a of the upper wall portion 230 of the spacer 200 in the Z-axis direction. In other words, the spacer 200 has a first surface 230a that faces the side plate 500 (insulator 600) in the Z-axis direction (third direction), and the side plate 500 (insulator 600) has a second surface 620a that faces the first surface 230a in the Z-axis direction (third direction). The first surface 230a has a plurality of protrusions 231 that project toward the second surface 620a in the Z-axis direction (third direction). The upper wall portion 620 of the insulator is positioned on its second surface 620a in contact with a plurality of protrusions 231 formed on the first surface 230a of the upper wall portion 230 of the spacers 200 in the Z-axis direction.

[0072] More specifically, as shown in Figure 6(a), when the side plate 500 is assembled to the energy storage element 100, the side plate 500 (insulator 600) is brought closer to the energy storage element 100 and spacer 200 from the negative X-axis direction. Then, as shown in Figure 6(b), the side plate 500 moves in the positive X-axis direction relative to the energy storage element 100 and spacer 200, crushing the protrusion 231a of the spacer 200 via the upper wall portion 620 of the insulator 600. Then, as shown in Figure 6(c), the side plate 500 moves in the positive X-axis direction relative to the energy storage element 100 and spacer 200, crushing the protrusion 231a of the spacer 200 with the upper wall portion 620 of the insulator 600, and then crushing the protrusion 231b as well. In other words, the side plate 500 (insulator 600) moves in the positive X-axis direction relative to the energy storage element 100 and the spacer 200, while sequentially crushing the protrusions 231a and 231b of the spacer 200.

[0073] Thus, the protrusions 231 (protrusions 231a and 231b) are crushed ribs, and the upper wall portion 620 of the insulator abuts against the multiple protrusions 231 (protrusions 231a and 231b) formed on the multiple spacers 200 in the Z-axis direction when these protrusions are crushed. This restricts the movement of the side plate 500 (insulator 600) in the Z-axis direction relative to the energy storage element 100 and the spacers 200.

[0074] Although this embodiment describes a case where multiple protrusions 231 are arranged, the embodiment of the present invention may also have only one protrusion 231. In this case, the protrusion 231 may be positioned at either the position of protrusions 231a and 231b, or it may be arranged in a shape that spans both protrusions 231a and 231b.

[0075] [5. Explanation of Effects] As described above, according to the energy storage device 10 of the embodiment of the present invention, the energy storage element 100 or spacer 200 and the side plate 500 have a first surface 230a and a second surface 620a that face each other in a third direction (Z-axis direction). A projection 231 is formed on at least one of the first surface 230a and the second surface 620a, which is positioned to protrude toward the other. This makes it easier to assemble the side plate 500 to the energy storage element 100 when assembling the side plate 500 to the energy storage element 100 from the first direction.

[0076] At least one of the first surface 230a and the second surface 620a of the energy storage element 100 or the spacer 200 and the side plate 500 (in this embodiment, the first surface 230a of the spacer 200) has a plurality of protrusions that project toward the other surface. This reduces the contact area of ​​one protrusion on the other component when assembling the side plate to the energy storage element from the first direction. Therefore, the assembly load caused by the protrusions can be reduced, making it even easier to assemble the side plate to the energy storage element.

[0077] In this configuration, multiple protrusions 231 are provided on at least one of the first surface 230a and second surface 620a of the energy storage element 100 or the spacer 200 and the side plate 500 (in this embodiment, the first surface 230a of the spacer 200), and the multiple protrusions 231 are positioned at different locations in the first direction. As a result, when assembling the side plate 500 to the energy storage element 100 from the first direction, the multiple protrusions 231 are sequentially contacted in the first direction. Therefore, the assembly load due to the protrusions 231 can be divided into multiple stages, thereby reducing the assembly load due to the protrusions 231 and making it easier to assemble the side plate 500 to the energy storage element 100.

[0078] The multiple protrusions 231 formed on at least one of the first surface 230a and second surface 620a of the energy storage element 100 or the spacer 200 and the side plate 500 (in this embodiment, the first surface 230a of the spacer 200) are arranged in positions that do not overlap in the first direction. In this way, since the multiple protrusions 231 are arranged in positions that do not overlap in the first direction, when assembling the side plate 500 to the energy storage element 100 from the first direction, one protrusion 231 is contacted before the next protrusion 231 is contacted in the first direction. This further reduces the assembly load caused by the protrusions 231, making it even easier to assemble the side plate 500 to the energy storage element 100.

[0079] The projection 231 is positioned so as to overlap with a portion of the energy storage element 100 when viewed from a third direction. At least one of the multiple projections 231 (in this embodiment, both projections 231a and 231b) is positioned so as to overlap with a portion of the energy storage element 100 when viewed from a third direction. This allows the side plate 500 to hold the energy storage element 100 more firmly in the third direction. This facilitates the assembly of the side plate 500 to the energy storage element 100 while improving the vibration resistance or shock resistance (load-bearing capacity) of the energy storage device 10.

[0080] The projection 231 has an inclined surface 231c. At least one of the multiple projections 231 (in this embodiment, both projections 231a and 231b) has an inclined surface 231c. This allows the side plate 500 to be assembled to the energy storage element 100 from the first direction along the inclined surface 231c. This further facilitates the assembly of the side plate 500 to the energy storage element 100.

[0081] [6. Explanation of Variations] Although the energy storage device 10 according to this embodiment has been described above, the present invention is not limited to the above embodiment. The embodiments disclosed herein are illustrative and not restrictive in all respects, and the scope of the present invention includes all modifications in the sense and scope equivalent to the claims.

[0082] In the above embodiment, the multiple protrusions 231 are positioned in non-overlapping locations in the X-axis and Y-axis directions, and are positioned at the same location in the Z-axis direction. However, the multiple protrusions 231 may be positioned in a partially overlapping location in at least one direction of the X-axis and Y-axis directions. The multiple protrusions 231 may be positioned so that they all overlap in the Y-axis direction. The multiple protrusions 231 may be positioned at different locations in the Z-axis direction (partially non-overlapping, or not overlapping at all) due to the first surface 230a being inclined in the Z-axis direction, etc. In other words, the multiple protrusions 231 only need to be positioned at different locations in the X-axis direction.

[0083] In the above embodiment, all of the protrusions 231 are positioned so as to overlap with a portion of the energy storage element 100 when viewed from the Z-axis direction. However, it is sufficient if at least a portion of the protrusions 231 overlap with a portion of the energy storage element 100 when viewed from the Z-axis direction, rather than all of them. Alternatively, it is sufficient if at least one of the protrusions 231 overlaps with the energy storage element 100 when viewed from the Z-axis direction, rather than all of the protrusions 231. Or, it is not necessary for all of the protrusions 231 to overlap with the energy storage element 100 when viewed from the Z-axis direction.

[0084] In the above embodiment, all projections 231 are assumed to have a curved inclined surface 231c. However, it is sufficient that at least one of the multiple projections 231 has an inclined surface 231c, and any of the projections 231 may not have an inclined surface 231c. The inclined surface 231c may be a flat inclined surface rather than a curved inclined surface. Alternatively, there may be a configuration in which none of the projections 231 have an inclined surface 231c.

[0085] In the above embodiment, all spacers 200 have the same configuration, but any of the spacers 200 may have a different configuration than described above.

[0086] In the above embodiment, the following modifications may be made. Figures 7A to 7C are front views showing the configuration of spacers 201 to 203 according to Modification 1 of this embodiment. Specifically, Figures 7A to 7C correspond to Figure 4(c), and show an enlarged view of the configuration of the X-axis negative projections 232 to 234 and their surroundings on spacers 201 to 203 as seen from the front (Y-axis negative direction).

[0087] As shown in Figures 7A, 7B, and 7C, in this modified example, spacers 201, 202, and 203 are arranged in place of spacer 200 in the above embodiment. Spacers 201, 202, and 203 have projections 232 (232a and 232b), projections 233 (233a and 233b), and projections 234 (234a and 234b), respectively, instead of projections 231 (231a and 231b) that spacer 200 has in the above embodiment. The other configurations are the same as in the above embodiment, so a detailed explanation is omitted.

[0088] The protrusions 232 (232a and 232b) are ribs formed on the first surface 230a of the upper wall portion 230 of the spacer 201, and have a hollow leaf spring shape (similar to the stepping stone of a vaulting box). The multiple protrusions 232 (232a and 232b), like the multiple protrusions 231, are arranged at different positions (non-overlapping positions) in the X-axis direction, and at positions that overlap with a part of the energy storage element 100 when viewed from the Z-axis direction, and have an inclined surface 232c. In Figure 7A, the end of the protrusion 232 on the X-axis positive direction (first direction) side is connected to the first surface 230a, but the end of the protrusion 232 on the X-axis positive direction (first direction) side is not required to be connected to the first surface 230a.

[0089] The projections 233 (233a and 233b) are ribs formed on the first surface 230a of the upper wall portion 230 of the spacer 202. They have a leaf spring shape similar to projection 232, but have a spring 233d. In other words, projection 233 has a configuration in which a leaf spring is supported by a spring 233d. The spring 233d may have any shape, such as helical or bellows-like, and may be made of any material, such as metal or resin. The multiple projections 233 (233a and 233b), like the multiple projections 231, are arranged at different positions (non-overlapping positions) in the X-axis direction, and at positions that overlap with a part of the energy storage element 100 when viewed from the Z-axis direction, and have an inclined surface 233c.

[0090] The protrusions 234 (234a and 234b) are plungers provided on the first surface 230a of the upper wall portion 230 of the spacer 203. The multiple protrusions 234 (234a and 234b), like the multiple protrusions 231, are arranged at different positions (non-overlapping positions) in the X-axis direction, and at positions that overlap with a part of the energy storage element 100 when viewed from the Z-axis direction, and each has an inclined surface 234c.

[0091] As described above, the energy storage device according to this modified example provides the same effects as the embodiment described above. As shown in this modified example, various forms of projections can be used as projections provided on the spacer. The shape of the projection is not limited to the complex shapes described above, but may be a columnar shape such as a cylindrical or prismatic shape, or a cylindrical shape such as a rectangular tube shape, and is not particularly limited to such shapes.

[0092] Thus, the spacer has a first surface 230a facing the second surface 620a of the side plate 500, and multiple protrusions are formed on the first surface 230a that project toward the second surface 620a. However, in addition to the protrusions of the spacer, or instead of the protrusions of the spacer, the energy storage element 100 may have a first surface facing the second surface 620a of the side plate 500, and multiple protrusions are formed on this first surface that project toward the second surface 620a. In this case, the energy storage device does not need to include the spacer 200. If the energy storage element 100 has protrusions, these protrusions are positioned to overlap with a part of the energy storage element 100 (the part other than the protrusions) when viewed from the Z-axis direction (third direction).

[0093] Furthermore, in addition to the protrusions of the energy storage element 100 or the spacer, or in place of such protrusions, multiple protrusions projecting toward the first surface 230a may be formed on the second surface 620a of the side plate 500. In this case, multiple protrusions may be formed on the upper wall portion 620 of the insulator 600, or if the side plate 500 does not have an insulator 600, multiple protrusions may be formed on the upper wall portion 520 of the side plate 500. In other words, the energy storage element 100 or the spacer has a first surface facing the side plate 500 in the Z-axis direction (third direction), and at least one of the first surface and the second surface 620a has multiple protrusions projecting toward the other in the Z-axis direction (third direction).

[0094] When multiple protrusions are formed on the insulator 600, the side plate 500 has an insulating member (insulator 600) on which multiple protrusions are formed. In this case, the side plate 500 has multiple protrusions via the insulating member (insulator 600). This makes it possible to realize a configuration that facilitates the assembly of the side plate 500 to the energy storage element 100.

[0095] An example of a configuration in which a protrusion is formed on the upper wall portion 520 of the side plate 500 described above will be specifically explained below. Figure 8 is a front view and a perspective view showing the configuration of a side plate 501 according to a modified example 2 of this embodiment. Specifically, Figure 8(a) is a front view showing the configuration of the upper wall portion 520 of the side plate 501 when viewed from the front (negative Y-axis direction), and Figure 8(b) is a perspective view showing the configuration of the upper wall portion 520 when viewed from diagonally below.

[0096] As shown in Figure 8, in this modified example, a side plate 501 is provided instead of the side plate 500 in the above embodiment. The side plate 501 has a second surface 520a on the upper wall portion 520 of the plate that faces the first surface of the energy storage element 100 or spacer, and has a plurality of protrusions 521 (521a and 521b) that project from the second surface 520a in the negative Z-axis direction. The other configurations are the same as in the above embodiment, so a detailed explanation is omitted.

[0097] The multiple protrusions 521 (521a and 521b) are formed by creating a notch 520b in the upper wall portion 520 of the plate and bending the notched portion in the negative Z-axis direction. The multiple protrusions 521 (521a and 521b) are positioned at different locations in the X-axis direction and overlap with a part of the energy storage element 100 when viewed from the Z-axis direction, and each has an inclined surface 521c. The inclined surface 521c is an inclined surface that slopes away from the side plate 501 (plate body portion 510) in the X-axis direction (positive X-axis direction) as it moves away from the energy storage element 100 in the Z-axis direction (positive Z-axis direction). In particular, as in this modified example, the protrusions 521 can be easily formed by cutting out the side plate 501 and bending the notched portion.

[0098] When the side plates 500 and 501 are assembled to the energy storage element 100 from the first direction, the protrusions 232, 233, 234, and 521 deform. The biasing force created by the deformation of the protrusions 232, 233, 234, and 521 restricts the movement of the side plate 500 (insulator 600) in the Z-axis direction relative to the energy storage element 100 and the spacer 200. Thus, the energy storage device according to this modified example achieves the same effects as the embodiment described above.

[0099] Although this modified example describes a case where multiple protrusions 232, 233, 234, and 521 are arranged, the embodiment of the present invention may also have only one protrusion 232, 233, 234, and 521. Arranging multiple protrusions 232, 233, 234, and 521 is preferable because it further reduces the assembly load caused by the protrusions, thus making the assembly of the side plate to the energy storage element even easier.

[0100] If protrusions are formed on the side plate 500 in addition to the protrusions on the energy storage element 100 or spacer, the multiple protrusions on the energy storage element 100 or spacer and the multiple protrusions on the side plate 500 may be arranged alternately in staggered positions. In this case, the energy storage element 100 or spacer and the side plate 500 may be assembled so that the multiple protrusions on the energy storage element 100 or spacer and the multiple protrusions on the side plate 500 are combined. The energy storage element 100 or spacer may have only one protrusion, or the side plate 500 may have only one protrusion. In other words, it is sufficient for the energy storage element 100 or spacer and the side plate 500 to have a total of multiple protrusions.

[0101] The present invention also includes forms constructed by arbitrarily combining the components included in the above embodiments and their modified examples.

[0102] The present invention can be realized not only as such an energy storage device, but also as a combination of the energy storage element 100 and a side plate, or as a combination of the energy storage element 100, a spacer and a side plate. [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] 10 Energy storage device 100 energy storage elements 110 Container 140 Electrode terminal 200, 201, 202, 203, 300 spacers 210 Spacer body 220 Spacer side wall 230 Spacer upper wall section 230a Front page 231, 231a, 231b, 232, 232a, 232b, 233, 233a, 233b, 234, 234a, 234b, 521, 521a, 521b protrusion 231c, 232c, 233c, 234c, 521c Slope 233d spring 240 Spacer bottom wall 400 End Plate 500, 501 Side Plates 510 Plate body 520 Plate upper wall 520a, 620a second side 520b Notch 530 Plate bottom wall 600 Insulators 610 Insulator Body 620 Insulator upper wall section 630 Insulator bottom wall

Claims

1. An energy storage device comprising an energy storage element and a side plate positioned in a first direction relative to the energy storage element, The energy storage element, or the spacer positioned in a second direction intersecting the first direction of the energy storage element, has a first surface facing the side plate in a third direction intersecting the first and second directions. The side plate has a second surface facing the first surface in the third direction, At least one of the first surface and the second surface has a plurality of protrusions that project toward the other surface. The plurality of protrusions are arranged at different positions in the first direction and the second direction. Energy storage device.

2. The side plate has an insulating member on which the plurality of protrusions are formed. The energy storage device according to claim 1.

3. An energy storage device comprising an energy storage element and a side plate positioned in a first direction relative to the energy storage element, The energy storage element, or the spacer positioned in a second direction intersecting the first direction of the energy storage element, has a first surface facing the side plate in a third direction intersecting the first and second directions. The side plate has a second surface facing the first surface in the third direction, The first surface has a plurality of protrusions that project toward the second surface. The plurality of protrusions are arranged at different positions in the first direction. Energy storage device.

4. The plurality of protrusions are arranged in positions that do not overlap in the first direction. The energy storage device according to any one of claims 1 to 3.

5. At least one of the plurality of protrusions is positioned so as viewed from the third direction that it overlaps with a part of the energy storage element. The energy storage device according to any one of claims 1 to 4.

6. At least one of the plurality of protrusions has an inclined surface that slopes away from the side plate in the first direction as it moves away from the energy storage element in the third direction. The energy storage device according to any one of claims 1 to 5.

Images