Power storage device

Abstract

A power storage device 10 is provided with a power storage element 210, a spacer 220 that is disposed in a predetermined direction (Z-axis direction) of the power storage element 210, and a bonding layer 270 that is disposed between the power storage element 210 and the spacer 220 and bonds the power storage element 210 and the spacer 220. The spacer 220 has a first protruding part 220b that is disposed at a position adjacent to the bonding layer 270 in a crossing direction crossing the predetermined direction, and protrudes toward the power storage element 210, and a second protruding part 220d that is disposed at a position different from that of the first protruding part 220b, protrudes toward the power storage element 210, and has a protrusion height lower than the first protruding part 220b.

Description

[Technical Field]

[0001] The present invention relates to an electricity storage device including an electricity storage element and a spacer. [Background technology]

[0002] Conventionally, there has been known an electric storage device that includes an electric storage element and a spacer, and the electric storage element and the spacer are bonded with an adhesive layer. For example, Patent Document 1 discloses an assembled battery (electric storage device) that includes a plurality of battery cells (electric storage elements) and separators (spacers), and the battery cells and the separators are bonded with an adhesive (adhesive layer). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-119156 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional energy storage device, the adhesive strength between the energy storage elements and the spacers may be reduced. Specifically, in the conventional energy storage device, in which the energy storage elements and the spacers are bonded together with an adhesive layer, the thickness of the adhesive layer varies due to the dimensional tolerances of each component, which may cause the adhesive layer to be compressed. Furthermore, the energy storage elements expand with use and repeatedly expand and contract with charging and discharging, which also compress the adhesive layer and subject the adhesive layer to repeated stress. As a result, in the conventional energy storage device, the adhesive layer between the energy storage elements and the spacers may be excessively compressed or may be subjected to repeated stress in a compressed state, which may cause the adhesive strength between the energy storage elements and the spacers to be reduced.

[0005] The present invention was made by the inventors of the present application with a new focus on the above-mentioned problem, and has an object to provide an electricity storage device that can improve the adhesiveness between electricity storage elements and spacers. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, an energy storage device according to one embodiment of the present invention comprises an energy storage element, a spacer arranged in a predetermined direction of the energy storage element, and an adhesive layer arranged between the energy storage element and the spacer and adhering the energy storage element and the spacer, wherein the spacer has a first protrusion arranged adjacent to the adhesive layer in a cross direction intersecting the predetermined direction and protruding toward the energy storage element, and a second protrusion arranged at a different position from the first protrusion and protruding toward the energy storage element with a protruding height lower than that of the first protrusion.

[0007] According to this, in the energy storage device, the spacer has a first protrusion disposed adjacent to the adhesive layer that bonds the energy storage element and the spacer, and a second protrusion having a protruding height lower than the first protrusion. Because the first protrusion is disposed adjacent to the adhesive layer in the spacer, even if the thickness of the adhesive layer varies due to dimensional tolerances of the components, the first protrusion can be crushed to absorb the variation. Furthermore, even if the energy storage element expands, the first protrusion can be crushed to absorb the expansion of the energy storage element. Furthermore, because the spacer has a second protrusion having a protruding height lower than the first protrusion, the second protrusion can prevent the first protrusion from being crushed too much. This allows the adhesive layer between the energy storage element and the spacer to maintain an appropriate thickness, preventing the adhesive layer from being overcompressed or being subjected to repeated stress in an overcompressed state. This improves the adhesion between the energy storage element and the spacer.

[0008] The second protrusion may be disposed at a position facing a center portion of the energy storage element.

[0009] According to this, since the central portion of the energy storage element is prone to swelling, the second protrusion of the spacer is positioned opposite the central portion of the energy storage element. This makes it possible to suppress swelling of the central portion of the energy storage element, thereby effectively suppressing excessive compression of the adhesive layer. Furthermore, by positioning the second protrusion at a position opposite the central portion of the energy storage element, the adhesive layer is positioned at a position not opposite the central portion. Here, the central portion of the energy storage element is prone to repeated expansion and contraction due to charging and discharging. Therefore, by positioning the adhesive layer at a position not opposite the central portion, it is possible to suppress the adhesive layer from being subjected to repeated stress due to the expansion and contraction of the energy storage element. As a result, the adhesion between the energy storage element and the spacer can be improved.

[0010] The spacer may have two of the first protrusions at positions sandwiching the adhesive layer in the intersecting direction.

[0011] According to this, since the spacer has two first protrusions at positions sandwiching the adhesive layer, it is possible to prevent the adhesive layer from protruding from a predetermined position (between the two first protrusions). As a result, the adhesive layer can be positioned in an appropriate position by the two first protrusions, thereby improving the adhesion between the energy storage element and the spacer.

[0012] The spacer may further include a third protruding portion disposed between the first protruding portion and the second protruding portion and having a protruding height lower than that of the first protruding portion.

[0013] According to this, the spacer has a third protruding portion between the first protruding portion and the second protruding portion, the third protruding portion having a protruding height lower than the first protruding portion. In this way, by disposing the third protruding portion, in addition to the second protruding portion, which has a protruding height lower than the first protruding portion, on the spacer, it is possible to further prevent the first protruding portion from being crushed too much. This further prevents the adhesive layer from being compressed too much or from being subjected to repeated stress in an overly compressed state, thereby improving the adhesion between the energy storage element and the spacer.

[0014] In addition, the storage element may have an electrode body having a flat portion formed at a position opposite the spacer, and at least a portion of the adhesive layer may be positioned in a position that does not overlap with the flat portion when viewed from the specified direction.

[0015] The portion of the energy storage element facing the flat portion of the electrode body is prone to expansion with use, and is prone to repeated expansion and contraction due to charging and discharging. For this reason, at least a portion of the adhesive layer is positioned so as not to overlap the flat portion. This prevents the adhesive layer from being excessively compressed by the expansion of the energy storage element or being subjected to repeated stress, thereby improving the adhesion between the energy storage element and the spacer.

[0016] The present invention can be realized not only as an electricity storage device but also as a spacer. [Effects of the Invention]

[0017] According to the electricity storage device of the present invention, the adhesion between the electricity storage elements and the spacers can be improved. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view showing the appearance of a power storage device according to an embodiment; [Figure 2] 2 is a perspective view showing the inside of the exterior body with the main body and the lid of the exterior body separated in the energy storage device according to the embodiment; FIG. [Figure 3] FIG. 2 is an exploded perspective view showing components inside an exterior body of the energy storage device according to the embodiment. [Figure 4] FIG. 2 is an exploded perspective view showing the components of the electricity storage unit according to the embodiment. [Figure 5] FIG. 2 is an exploded perspective view showing the components of the energy storage device according to the embodiment. [Figure 6] 1A and 1B are a perspective view and a cross-sectional view showing a configuration of a spacer according to an embodiment. [Figure 7]10 is a plan view showing the configuration of a spacer according to an embodiment and the positional relationship with an energy storage element. FIG. [Figure 8] 10 is a cross-sectional view showing a state in which a spacer and an energy storage element according to an embodiment are bonded together by an adhesive layer. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, with reference to the drawings, a description will be given of an energy storage device according to an embodiment of the present invention (including its modified examples). Note that the embodiments described below all show comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, manufacturing processes, and the order of manufacturing processes shown in the following embodiments are merely examples and are not intended to limit the present invention. Furthermore, in each drawing, dimensions and the like are not strictly illustrated. Furthermore, in each drawing, the same or similar components are assigned the same reference numerals.

[0020] In the following description and drawings, the longitudinal direction of the exterior body of the energy storage device, the arrangement direction of the energy storage unit and the electrical device, the arrangement direction of the pair of side plates, the extension direction of the pair of end plates, the opposing direction of the short side surfaces of the container of the energy storage element, or the arrangement direction of the pair of electrode terminals of one energy storage element is defined as the X-axis direction. The arrangement direction of the energy storage element and the bus bar or bus bar frame, or the arrangement direction of the main body and the lid of the container of the energy storage element is defined as the Y-axis direction. The arrangement direction of the main body and the lid of the exterior body of the energy storage device, the arrangement direction of the pair of end plates, the arrangement direction of the energy storage element and the end plates, the opposing direction of the long side surfaces of the container of the energy storage element, the flattening direction of the energy storage element, the stacking direction of the electrode plates of the electrode body of the energy storage element, or the up-down direction is defined as the Z-axis direction. The X-axis, Y-axis, and Z-axis directions intersect each other (orthogonal in this embodiment). Note that depending on the usage mode, the Z-axis may not be the up-down direction; however, for convenience of explanation, the Z-axis will be described below as the up-down direction.

[0021] In the following description, for example, the positive X-axis direction refers to the direction of the X-axis arrow, and the negative X-axis direction refers to the direction opposite to the positive X-axis direction. The same applies to the Y-axis and Z-axis directions. In the following, the Z-axis direction may also be referred to as a predetermined direction, and a direction intersecting with the predetermined direction (any direction within the XY plane) may also be referred to as an intersecting direction. Furthermore, expressions indicating relative directions or attitudes, such as parallel and orthogonal, may also include cases where the directions or attitudes are not strictly those of interest. For example, saying that two directions are orthogonal does not only mean that the two directions are completely orthogonal, but also means that the directions are substantially orthogonal, i.e., there may be a difference of, for example, a few percent.

[0022] (Embodiment) [1 General Description of the Power Storage Device 10] First, a schematic configuration of an energy storage device 10 according to the present embodiment will be described. Fig. 1 is a perspective view showing the appearance of the energy storage device 10 according to the present embodiment. Fig. 2 is a perspective view showing the inside of the exterior body 100 of the energy storage device 10 according to the present embodiment, with the main body and the lid of the exterior body 100 separated. Fig. 3 is an exploded perspective view showing the components inside the exterior body 100 of the energy storage device 10 according to the present embodiment.

[0023] The power storage device 10 is a device that can charge with electricity from an external source and discharge electricity to the outside, and in this embodiment, has a substantially rectangular parallelepiped shape. For example, the power storage device 10 is a battery module (battery assembly) used for power storage or power supply purposes. Specifically, the power storage device 10 is used as a battery for driving or starting the engine of a mobile object such as an automobile, motorcycle, personal watercraft, ship, snowmobile, agricultural machinery, construction machinery, or electric railway vehicle. Examples of the automobile include an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a gasoline-powered automobile. Examples of the electric railway vehicle include a train, a monorail, and a linear motor car. The power storage device 10 can also be used as a stationary battery for home use or a power generator.

[0024] 1 to 3, the energy storage device 10 includes an exterior body 100, an energy storage unit 200 housed in the exterior body 100, a mounting member 300, an electric device 400, and a bus bar unit 500. In addition to the above components, the energy storage device 10 may also include an exhaust section for exhausting gas discharged from the energy storage unit 200 to the outside of the exterior body 100, and a connector connected to the electric device 400 by an electric wire or the like for transmitting signals to the outside.

[0025] The exterior body 100 is a box-shaped (approximately rectangular parallelepiped) container (module case) that constitutes the exterior body of the energy storage device 10. In other words, the exterior body 100 is disposed outside the energy storage unit 200, the electrical equipment 400, etc., and secures the energy storage unit 200, the electrical equipment 400, etc. in predetermined positions to protect them from impacts and the like. The exterior body 100 is formed from an insulating material such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyethersulfone (PES), ABS resin, or a composite material thereof, or a metal with an insulating coating. The exterior body 100 thereby prevents the power storage unit 200, the electric device 400, etc. from coming into contact with external metal members, etc. Note that the exterior body 100 may be formed of a conductive member such as a metal, as long as the electrical insulation of the power storage unit 200, the electric device 400, etc. is maintained.

[0026] The exterior body 100 includes an exterior body main body 110 constituting the main body of the exterior body 100, and an exterior body lid 120 constituting the lid of the exterior body 100. The exterior body main body 110 is a bottomed rectangular cylindrical housing (chassis) with an opening formed therein, and houses the energy storage element 210, the electrical device 400, and the like. The exterior body lid 120 is a flat rectangular member that closes the opening of the exterior body main body 110. The exterior body lid 120 is joined to the exterior body main body 110 preferably in an airtight or watertight manner by adhesive, heat sealing, ultrasonic welding, or the like. Furthermore, the exterior body lid 120 is provided with external terminals 130, which are a pair of module terminals (common terminals) on the positive and negative sides. The energy storage device 10 charges with electricity from the outside and discharges electricity to the outside via the pair of external terminals 130. The external terminals 130 are formed of a conductive metal material such as aluminum, an aluminum alloy, copper, or a copper alloy.

[0027] The energy storage unit 200 has a shape that is flat in the Z-axis direction and long in the X-axis direction, with multiple energy storage elements 210 placed horizontally (laying on their side) and stacked flat in the Z-axis direction and arranged in the X-axis direction. Specifically, the energy storage unit 200 has a configuration in which the multiple energy storage elements 210 arranged in the Z-axis direction and the X-axis direction are sandwiched in the Z-axis direction and the X-axis direction by a pair of end plates 230 and a pair of side plates 240, together with spacers 220 and 223. A more detailed description of the configuration of the energy storage unit 200 will be given later.

[0028] The electric device 400 is a device that can monitor the state of the energy storage elements 210 included in the energy storage unit 200 and control the energy storage elements 210, and is attached to the energy storage unit 200. In the present embodiment, the electric device 400 is a flat rectangular member that is arranged at an end of the energy storage unit 200 in the longitudinal direction, that is, in the positive direction of the X-axis of the energy storage unit 200. The electric device 400 has electric components such as a circuit board, a shunt resistor, and a connector that monitor the charge and discharge states of the energy storage elements 210 and control the charge and discharge of the energy storage elements 210. The electric device 400 has a configuration in which these electric components are housed in an insulating cover member.

[0029] The mounting member 300 is a member that mounts the electric device 400 to the power storage unit 200. That is, the mounting member 300 is a flat plate-like member that is disposed between the power storage unit 200 and the electric device 400, and is mounted to the power storage unit 200, and to which the electric device 400 is mounted. The mounting member 300 is formed of, for example, any electrically insulating resin material that can be used for the exterior body 100 described above.

[0030] The mounting member 300 is arranged to face a surface of the energy storage unit 200 that is different from the surface on which the electrode terminals of the energy storage elements 210 are arranged. Specifically, the mounting member 300 is arranged in the X-axis direction of the energy storage unit 200. In the present embodiment, the mounting member 300 is attached to a side surface of the energy storage unit 200 that is in the positive direction of the X-axis, thereby attaching the electric device 400 to the side surface of the energy storage unit 200 that is in the positive direction of the X-axis in an upright position (a position parallel to the YZ plane). The mounting member 300 is also attached to at least one of the pair of end plates 230 of the energy storage unit 200 and the side plate 240 that connects the pair of end plates 230. In the present embodiment, the mounting member 300 is attached to both of the pair of end plates 230 and the side plate 240 that is in the positive direction of the X-axis.

[0031] The busbar unit 500 is a member that electrically connects the power storage unit 200 and the electric device 400, electrically connects the electric device 400 and the external terminal 130, and electrically connects the power storage unit 200 and the external terminal 130. The busbar unit 500 includes a busbar 510 and a relay 520.

[0032] The bus bar 510 is a plate-shaped member that connects a bus bar 250 (described later) included in the power storage unit 200 to the electric device 400, connects the electric device 400 to the external terminal 130, connects the bus bar 250 to the relay 520, and connects the relay 520 to the external terminal 130. In the present embodiment, the bus bar 510 is connected (joined) to the bus bar 250, the electric device 400, the external terminal 130, or the relay 520 by bolting, but may be connected (joined) by welding, crimping, or the like. The bus bar 510 is formed of, for example, a conductive member made of a metal such as aluminum, an aluminum alloy, copper, a copper alloy, or nickel, or a combination thereof, or a conductive member other than a metal. The relay 520 is a relay (electric relay) that is arranged between the power storage unit 200 and the external terminal 130 via the bus bar 510.

[0033] [2. Description of the Configuration of the Power Storage Unit 200] Next, the configuration of the energy storage unit 200 will be described in detail with reference to Fig. 4 in addition to Fig. 3. Fig. 4 is an exploded perspective view showing the components of the energy storage unit 200 according to the present embodiment. Note that in Fig. 4, bus bar 250 and bus bar frame 260 of the energy storage unit 200 are omitted.

[0034] As shown in Figures 3 and 4, the energy storage unit 200 has energy storage elements 210 (211, 212), spacers 220 (221, 222), 223, end plates 230 (231, 232), side plates 240 (241, 242, 243), a bus bar 250, and a bus bar frame 260.

[0035] The energy storage elements 210 are secondary batteries (single cells) that can charge and discharge electricity, and more specifically, are nonaqueous electrolyte secondary batteries such as lithium-ion secondary batteries. The energy storage elements 210 have a flat rectangular parallelepiped (rectangular) shape. In this embodiment, eight energy storage elements 210 are placed horizontally (laying on their sides) (with the long sides of the energy storage elements 210 facing the Z-axis direction) and arranged in the Z-axis and X-axis directions. Specifically, four first energy storage elements 211 on the negative X-axis direction side are stacked (flat) in the Z-axis direction, and four second energy storage elements 212 on the positive X-axis direction side are stacked (flat) in the Z-axis direction. The four first energy storage elements 211 and the four second energy storage elements 212 are arranged side by side in the X-axis direction. A detailed description of the configuration of the energy storage elements 210 will be given later.

[0036] The number of the energy storage elements 210 is not particularly limited, and any number of the energy storage elements 210 may be stacked (flat) in the Z-axis direction, or any number of the energy storage elements 210 may be arranged in the X-axis direction. That is, the energy storage unit 200 may have only one energy storage element 210. The shape of the energy storage element 210 is not limited to the above-mentioned rectangular shape, and may be other shapes such as a polygonal prism, a cylindrical shape, an elliptical cylindrical shape, or an oblong cylindrical shape. The energy storage element 210 is not limited to a nonaqueous electrolyte secondary battery, and may be a secondary battery other than a nonaqueous electrolyte secondary battery, or may be a capacitor. The energy storage element 210 may not be a secondary battery, but may be a primary battery that can use stored electricity without the user having to charge it. The energy storage element 210 may be a laminate-type energy storage element.

[0037] Spacers 220 (221, 222), 223 are flat, rectangular members that are arranged adjacent to and to the side (Z-axis direction or X-axis direction) of energy storage element 210 and electrically insulate energy storage element 210 from other members. Spacers 220, 223 are formed of, for example, any electrically insulating resin material that can be used for exterior body 100 described above.

[0038] Specifically, the spacers 221 are intermediate spacers (inter-cell spacers) arranged in a predetermined direction (Z-axis direction) of the energy storage elements 210. That is, the spacers 221 are arranged between two adjacent energy storage elements 210 (between two first energy storage elements 211 and between two second energy storage elements 212) to electrically insulate the two energy storage elements 210. In the present embodiment, three spacers 221 are arranged corresponding to four first energy storage elements 211, but when the number of first energy storage elements 211 is other than four, the number of spacers 221 is also changed appropriately depending on the number of first energy storage elements 211. The same applies to the second energy storage elements 212.

[0039] The spacers 222 are end spacers arranged in a predetermined direction (Z-axis direction) of the end storage elements 210. That is, the spacers 222 are arranged between the end storage elements 210 (first storage elements 211 and second storage elements 212 at the end) and the end plates 230 (231, 232), and electrically insulate the end storage elements 210 from the end plates 230 (231, 232). That is, two spacers 222 are arranged on both sides of the four first storage elements 211 in the Z-axis direction, and two spacers 222 are arranged on both sides of the four second storage elements 212 in the Z-axis direction. A detailed description of the configuration of these spacers 220 (spacers 221, 222) will be given later.

[0040] The spacers 223 are disposed between the energy storage elements 210 and the side plates 240 (241, 242, 243) and electrically insulate the energy storage elements 210 from the side plates 240 (241, 242, 243). That is, two spacers 223 are disposed on both sides of the four first energy storage elements 211 in the X-axis direction between the four first energy storage elements 211 and the side plates 241 and 243. Furthermore, two spacers 223 are disposed on both sides of the four second energy storage elements 212 in the X-axis direction between the four second energy storage elements 212 and the side plates 242 and 243.

[0041] The end plates 230 and the side plates 240 are members (restraining members) that compress (restrain) the energy storage elements 210 from the outside in the Z-axis direction. That is, the end plates 230 and the side plates 240 sandwich the energy storage elements 210 and the spacers 220 from both sides in the Z-axis direction, thereby compressing (restraining) each of the energy storage elements 210 and the spacers 220 from both sides in the Z-axis direction. The end plates 230 and the side plates 240 are formed of metal members such as stainless steel, aluminum, aluminum alloy, iron, plated steel plate, etc., but may also be formed of an insulating member such as a highly rigid resin.

[0042] The end plates 230 (231, 232) are a pair of flat plate-shaped members that are arranged at positions sandwiching the plurality of energy storage elements 210 (the plurality of first energy storage elements 211 and the plurality of second energy storage elements 212) and the plurality of spacers 220 in the Z-axis direction, and sandwich these in the Z-axis direction. As a result, the pair of end plates 230 collectively restrain the plurality of energy storage elements 210 and the plurality of spacers 220 in the Z-axis direction (collectively imparting a restraining force in the Z-axis direction to the plurality of energy storage elements 210 and the plurality of spacers 220). Note that, of the pair of end plates 230, end plate 231 is the end plate 230 on the negative side of the Z-axis, and end plate 232 is the end plate 230 on the positive side of the Z-axis.

[0043] The side plates 240 (241, 242, 243) are flat members attached at both ends to a pair of end plates 230, and connect the pair of end plates 230 to restrain the plurality of energy storage elements 210 and the plurality of spacers 220. In other words, the side plates 240 are arranged extending in the Z-axis direction so as to straddle the plurality of energy storage elements 210 and the plurality of spacers 220, and apply a restraining force to the plurality of energy storage elements 210 etc. in the arrangement direction (Z-axis direction).

[0044] In the present embodiment, side plate 241 is arranged in the negative direction of the X axis from first energy storage element 211, side plate 242 is arranged in the positive direction of the X axis from second energy storage element 212, and side plate 243 is arranged between first energy storage element 211 and second energy storage element 212. Side plates 241, 242, and 243 are attached at both ends in the Z axis direction to both ends and the center of a pair of end plates 230 in the X axis direction. Note that side plate 240 has a through hole formed therethrough in the Y axis direction for weight reduction and the like, but the through hole need not be formed.

[0045] In this manner, the end plate 230 and the side plate 240 sandwich and restrain the plurality of energy storage elements 210 and the plurality of spacers 220 from both sides in the X-axis direction and both sides in the Z-axis direction. The end plate 230 (231, 232) and each side plate 240 are connected (joined) to each other by a plurality of connecting members 230a (231a, 232a) aligned in the Y-axis direction. In this embodiment, the connecting members 230a are bolts that penetrate the end plate 230 and are threadedly engaged with female threads formed in the side plate 240, thereby connecting (fastening) the end plate 230 and the side plate 240. The arrangement positions and number of the connecting members 230a are not particularly limited. Other methods may be used to connect the end plate 230 and the side plate 240, such as welding, crimping, adhesive bonding, or welding.

[0046] Bus bar 250 is a flat member connected to energy storage elements 210. Specifically, bus bar 250 is arranged in the negative Y-axis direction of the multiple energy storage elements 210, and is connected (joined) to electrode terminals of the multiple energy storage elements 210 and to bus bar 510. In other words, bus bar 250 connects the electrode terminals of the multiple energy storage elements 210 to each other, and also connects electrode terminals of end energy storage elements 210 to bus bar 510. In this embodiment, bus bar 250 and the electrode terminals of energy storage elements 210 are connected (joined) by welding, but may be connected (joined) by bolting or the like. Bus bar 250 is formed, for example, from any of the materials that can be used for bus bar 510 described above. In addition, in this embodiment, the bus bar 250 connects two storage elements 210 in parallel to form four sets of storage element groups, and these four sets of storage element groups are connected in series, but the bus bar 250 may also connect all eight storage elements 210 in series, or may have another configuration.

[0047] In addition, an electric wire 251 for detecting voltage and the like is connected to the bus bar 250. The electric wire 251 is also connected to the electric device 400, and transmits information such as the voltage of the energy storage element 210 to the electric device 400. The electric wire 251 is also connected to the thermistor 252, and transmits temperature information of the energy storage element 210 to the electric device 400.

[0048] The bus bar frame 260 is a flat, rectangular insulating member that can electrically insulate the bus bar 250 from other members and can regulate the position of the bus bar 250. The bus bar frame 260 is formed, for example, from any electrically insulating resin material that can be used for the above-described exterior body 100. The bus bar frame 260 is arranged in the negative Y-axis direction of the multiple energy storage elements 210 and is positioned relative to the multiple energy storage elements 210. Specifically, the bus bar frame 260 is attached to at least one end plate 230 of the pair of end plates 230 (in this embodiment, both end plates 230). The bus bar 250, the electric wire 251, and the thermistor 252 are also positioned on the bus bar frame 260. As a result, the bus bar 250 is positioned relative to the multiple energy storage elements 210 and joined to electrode terminals of the multiple energy storage elements 210.

[0049] [3. Description of the Configuration of Energy Storage Element 210] Next, the configuration of the energy storage element 210 will be described in detail. Fig. 5 is an exploded perspective view showing each component of the energy storage element 210 according to this embodiment. Specifically, Fig. 5 shows an exploded view of each part of the energy storage element 210 shown in Fig. 4 in a vertically placed (standing) state. Note that all eight energy storage elements 210 (four first energy storage elements 211 and four second energy storage elements 212) have the same configuration, and therefore the configuration of one energy storage element 210 will be described below.

[0050] As shown in FIG. 5, the energy storage element 210 includes a container 210a, a pair of electrode terminals 210b (positive and negative), and a pair of upper gaskets 210c (positive and negative). The container 210a also contains a pair of lower gaskets 210d (positive and negative), a pair of current collectors 210e (positive and negative), and an electrode assembly 210f. An electrolyte (non-aqueous electrolyte) is enclosed within the container 210a, but this is not shown. The electrolyte may be of any type, provided it does not impair the performance of the energy storage element 210, and various electrolytes may be selected. In addition to the above components, spacers may be disposed on the sides or below the electrode assembly 210f, an insulating film enclosing the electrode assembly 210f, or an insulating sheet covering the outer surface of the container 210a.

[0051] The container 210a is a rectangular parallelepiped (square or box-shaped) case having a container body 210a1 with an opening formed therein and a container lid 210a2 that closes the opening of the container body 210a1. With this configuration, the container 210a can be sealed by, for example, welding the container body 210a1 and the container lid 210a2 together after the electrode assembly 210f and other components are housed inside the container body 210a1. The materials for the container body 210a1 and the container lid 210a2 are not particularly limited, but are preferably weldable metals such as stainless steel, aluminum, aluminum alloy, iron, and plated steel sheet.

[0052] The container body 210a1 is a rectangular cylindrical member with a bottom that constitutes the main body of the container 210a, and has an opening on the negative Y-axis side. That is, the container body 210a1 has a pair of rectangular, planar (flat) long side surfaces on both sides in the Z-axis direction, a pair of rectangular, planar (flat) short side surfaces on both sides in the X-axis direction, and a rectangular, planar (flat) bottom surface on the positive Y-axis side. The container lid 210a2 is a rectangular plate-like member that constitutes the lid of the container 210a, and is disposed on the negative Y-axis side of the container body 210a1, extending in the X-axis direction.

[0053] The electrode body 210f is an electricity storage element (power generating element) formed by laminating a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate is formed by forming a positive electrode active material layer on a positive electrode substrate layer, which is a current collecting foil made of a metal such as aluminum or an aluminum alloy. The negative electrode plate is formed by forming a negative electrode active material layer on a negative electrode substrate layer, which is a current collecting foil made of a metal such as copper or a copper alloy. As the active material used for 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 absorbing and releasing lithium ions. In this embodiment, the electrode body 210f is a wound type (so-called vertically wound type) electrode body formed by winding electrode plates (positive electrode plate and negative electrode plate) around a winding axis (a virtual axis parallel to the X-axis direction) extending in the X-axis direction.

[0054] Here, because the electrode plates (positive and negative electrode plates) of the electrode assembly 210f are stacked in the Z-axis direction, the Z-axis direction is also referred to as the stacking direction. That is, the electrode assembly 210f is formed by stacking the electrode plates in the stacking direction. Note that the electrode assembly 210f has a pair of flat portions 210f1 aligned in the Z-axis direction and a pair of curved portions 210f2 aligned in the Y-axis direction by winding the electrode plates. The stacking direction is the stacking direction of the electrode plates in the flat portion 210f1. The flat portion 210f1 is a flat portion connecting the ends of the pair of curved portions 210f2, and the curved portion 210f2 is a portion curved in a semicircular shape or the like so as to protrude in the Y-axis direction. The stacking direction can also be defined as the direction in which the flat surface of the flat portion 210f1 faces or the direction in which the pair of flat portions 210f1 face each other. Therefore, it can be said that the multiple first energy storage elements 211 are arranged in the stacking direction, and the multiple second energy storage elements 212 are also arranged in the stacking direction. The X-axis direction in which the first energy storage elements 211 and the second energy storage elements 212 are arranged is also referred to as the arrangement direction. In other words, the first energy storage elements 211 and the second energy storage elements 212 are arranged in an arrangement direction that intersects with the stacking direction.

[0055] Furthermore, since the electrode body 210f is wound with the positive and negative electrode plates shifted from each other in the X-axis direction, the positive and negative electrode plates have portions (active material layer non-formed portions) at the ends in the shifted direction where the active material is not formed (coated) and the base material layer is exposed. In other words, the electrode body 210f has connection portions 210f3 at both ends in the X-axis direction that protrude on both sides in the X-axis direction from the flat portion 210f1 and the curved portion 210f2, and are formed by stacking the active material layer non-formed portions of the positive and negative electrode plates and connecting to the current collector 210e.

[0056] The electrode body 210f may be an electrode body of any shape, such as a so-called horizontally wound electrode body formed by winding an electrode plate around a winding axis extending in the Y-axis direction, a laminated (stacked) electrode body formed by stacking multiple flat electrode plates, or a bellows-shaped electrode body in which the electrode plates are folded like bellows. In the case of a horizontally wound electrode body, the flat portion is the flat part other than the curved part and the connection part (tab) with the current collector, and in the case of a laminated (stacked) and bellows-shaped electrode body, the flat part is the flat part other than the connection part (tab) with the current collector.

[0057] The electrode terminals 210b are terminals (positive and negative terminals) of the energy storage element 210, and are arranged on the container lid portion 210a2 so as to protrude in the negative Y-axis direction. The electrode terminals 210b are electrically connected to the positive and negative electrode plates of the electrode body 210f via the current collector 210e. The electrode terminals 210b are formed of a conductive material such as a metal, such as aluminum, an aluminum alloy, copper, or a copper alloy.

[0058] The current collector 210e is a conductive member (positive electrode current collector and negative electrode current collector) electrically connected to the electrode terminal 210b and the connection portion 210f3 of the electrode body 210f. The current collector 210e is made of aluminum, an aluminum alloy, copper, a copper alloy, or the like. The upper gasket 210c and the lower gasket 210d are flat, electrically insulating sealing members disposed between the container lid portion 210a2 and the electrode terminal 210b and the current collector 210e. The upper gasket 210c and the lower gasket 210d are made of, for example, any electrically insulating resin material that can be used for the exterior body 100 described above.

[0059] [4 Explanation of the structure of the spacer 220] Next, the configuration of the spacer 220 (spacers 221, 222) will be described in detail. Note that the multiple spacers 221 all have the same configuration, and the spacer 222 has the same configuration of protrusions formed on both sides in the Z-axis direction as the spacer 221. For this reason, the following description will be given with one spacer 221 shown to illustrate the configurations of the spacers 221 and 222.

[0060] FIG. 6 is a perspective view and a cross-sectional view showing the configuration of a spacer 220 according to this embodiment. Specifically, FIG. 6(a) is a perspective view showing the configuration of the spacer 221 shown in FIG. 4, and FIG. 6(b) shows the configuration of the spacer 221 shown in FIG. 6(a) when cut along a plane parallel to the XZ plane passing through line VIb-VIb. FIG. 7 is a plan view showing the configuration of the spacer 220 according to this embodiment and the positional relationship with the energy storage element 210. Specifically, FIG. 7(a) is a plan view showing the configuration of the spacer 221, and FIG. 7(b) is a plan view showing the configuration of the energy storage element 210. FIG. 8 is a cross-sectional view showing a state in which the spacer 220 according to this embodiment and the energy storage element 210 are bonded together with an adhesive layer 270. Specifically, (a) of Fig. 8 is a cross-sectional view showing a state in which the spacer 221 and the energy storage element 210 are bonded together when the energy storage device 10 is assembled, and (b) of Fig. 8 is a cross-sectional view showing a state in which the spacer 221 and the energy storage element 210 are bonded together after assembly of the energy storage device 10 is completed or during use. Note that Fig. 8 shows a cross section taken at the same position as Fig. 6(b).

[0061] As shown in these figures, the spacer 220 (spacer 221) has a spacer main body 220a, a first protruding portion 220b, an adhesive layer arrangement portion 220c, a second protruding portion 220d, and a third protruding portion 220e. The spacer 221 has the first protruding portion 220b, the adhesive layer arrangement portion 220c, the second protruding portion 220d, and the third protruding portion 220e on both the surface of the spacer main body 220a on the positive Z-axis direction side and the surface on the negative Z-axis direction side. Therefore, the following description will focus on the first protruding portion 220b, the adhesive layer arrangement portion 220c, the second protruding portion 220d, and the third protruding portion 220e on the positive Z-axis direction side of the spacer main body 220a, and will omit a description of the negative Z-axis side.

[0062] Spacer body 220a is a flat, rectangular member that constitutes the main body of spacer 220, and is disposed opposite the long side surfaces of containers 210a of energy storage elements 210 (see FIGS. 4, 8, etc.). In other words, spacer body 220a is disposed between the long side surfaces of containers 210a of two energy storage elements 210.

[0063] The first protrusion 220b is a protruding portion that protrudes from the spacer main body 220a in the positive direction of the Z axis. That is, the first protrusion 220b protrudes toward the energy storage element 210 (more specifically, toward the long side surface of the container 210a of the energy storage element 210). Specifically, the first protrusion 220b is an annular (quadratic annular) rib (protrusion) formed so as to surround the outer periphery of the spacer main body 220a. In this embodiment, two annular first protrusions 220b are arranged at an interval on the outer periphery of the spacer main body 220a.

[0064] The adhesive layer disposing portion 220c is a ring-shaped (quadratic ring-shaped) recessed portion disposed between the two first protruding portions 220b, and an adhesive layer 270 (described later) is disposed (applied) thereon. That is, the first protruding portion 220b is disposed at a position adjacent to the adhesive layer disposing portion 220c in an intersecting direction intersecting the predetermined direction (Z-axis direction). In other words, the two first protruding portions 220b are disposed at positions sandwiching the adhesive layer disposing portion 220c in the intersecting direction. Note that the intersecting direction is any direction intersecting the Z-axis direction, and in this embodiment, is the X-axis direction and the Y-axis direction. That is, the two first protruding portions 220b are disposed at positions sandwiching the adhesive layer disposing portion 220c in the X-axis direction and the Y-axis direction.

[0065] 7, the energy storage element 210 has an electrode body 210f on which a flat portion 210f1 is formed at a position facing the spacer 220. When viewed from a predetermined direction (Z-axis direction), the inner first protrusion 220b of the two first protrusions 220b is disposed at a position overlapping the flat portion 210f1, while the outer first protrusion 220b is disposed at a position not overlapping the flat portion 210f1. Therefore, at least a portion of the adhesive layer arrangement portion 220c is disposed at a position not overlapping the flat portion 210f1 of the electrode body 210f when viewed from the predetermined direction (Z-axis direction). In this embodiment, when viewed from the predetermined direction (Z-axis direction), at least a portion (a portion on both sides in the X-axis direction and on the negative Y-axis direction) of the outer first protrusion 220b is disposed at a position not overlapping the electrode body 210f. Therefore, at least a portion of the adhesive layer arrangement portion 220c is disposed at a position not overlapping the electrode body 210f when viewed from the predetermined direction (Z-axis direction).

[0066] Similar to the first protrusion 220b, the second protrusion 220d is a protruding portion that protrudes from the spacer main body 220a in the positive direction of the Z axis. That is, the second protrusion 220d is disposed at a position different from that of the first protrusion 220b, and protrudes toward the energy storage device 210 (more specifically, toward the long side surface of the container 210a of the energy storage device 210). Specifically, the second protrusion 220d is formed at a position more inward than the first protrusion 220b, has a width in the X-axis direction or the Y-axis direction greater than that of the first protrusion 220b, and is lower in height in the Z axis direction than that of the first protrusion 220b. In the present embodiment, the second protrusion 220d is a circular protrusion that is formed at the center of the spacer main body 220a, is disposed at a position facing the center of the energy storage device 210, and protrudes lower in height than the first protrusion 220b.

[0067] Like the first protrusion 220b, the third protrusion 220e is a protruding portion protruding from the spacer main body 220a in the positive direction of the Z axis. Specifically, the third protrusion 220e is a linear rib (protrusion) disposed between the first protrusion 220b and the second protrusion 220d and protruding toward the energy storage device 210 (specifically, toward the long side surface of the container 210a of the energy storage device 210). In this embodiment, a plurality of third protrusions 220e are disposed extending radially from the periphery of the second protrusion 220d toward the first protrusion 220b. Specifically, four third protrusions 220e are disposed extending from both ends in the X axis direction and both ends in the Y axis direction of the second protrusion 220d toward both sides in the X axis direction and both ends in the Y axis direction. The third protrusions 220e are connected to the second protrusion 220d and are not connected to the first protrusion 220b. Furthermore, the third protruding portion 220e is formed to be wider than the first protruding portion 220b and to have a lower protruding height (lower height in the Z-axis direction) than the first protruding portion 220b. In this embodiment, the third protruding portion 220e has the same protruding height as the second protruding portion 220d.

[0068] As shown in FIG. 8A, an adhesive layer 270 is disposed in the adhesive layer disposing portion 220c between the two first protruding portions 220b. In this embodiment, an adhesive is applied to the entire adhesive layer disposing portion 220c, and the adhesive is solidified to form the adhesive layer 270 over the entire adhesive layer disposing portion 220c. As a result, the adhesive layer 270 becomes a ring-shaped (quadratic ring-shaped) portion disposed between the two first protruding portions 220b. In the state shown in FIG. 8A (when the energy storage device 10 is assembled), the first protruding portion 220b abuts against the container 210a of the energy storage element 210, but the second protruding portion 220d and the third protruding portion 220e do not abut against the container 210a. The adhesive used for the adhesive layer 270 may be, for example, a gel-like resin material. Alternatively, a liquid or solid adhesive such as a hot-melt adhesive may also be used.

[0069] In this way, the first protrusions 220b are ribs for disposing (applying) the adhesive layer 270, and are arranged at positions adjacent to the adhesive layer 270 in an intersecting direction (X-axis direction in FIG. 8) that intersects with the above-mentioned predetermined direction (Z-axis direction). In other words, the spacer 220 has two first protrusions 220b at positions sandwiching the adhesive layer 270 in the intersecting direction. The adhesive layer 270 is arranged between the energy storage element 210 and the spacer 220, and bonds the energy storage element 210 and the spacer 220 together.

[0070] 7, at least a portion of the adhesive layer disposing portion 220c is disposed at a position that does not overlap with the flat portion 210f1 of the electrode body 210f when viewed from the predetermined direction (Z-axis direction), and therefore at least a portion of the adhesive layer 270 is disposed at a position that does not overlap with the flat portion 210f1. Note that, as described above, in this embodiment, at least a portion of the adhesive layer disposing portion 220c is disposed at a position that does not overlap with the electrode body 210f when viewed from the predetermined direction (Z-axis direction), and therefore at least a portion of the adhesive layer 270 is disposed at a position that does not overlap with the electrode body 210f.

[0071] 8(b), after assembly of the energy storage device 10 is completed or during use, the long side of the container 210a of the energy storage device 210 approaches the spacer 220 due to dimensional tolerances of the components, expansion of the energy storage device 210, or the like. As a result, the first protrusion 220b is compressed and its protrusion height decreases, which in turn compresses the adhesive layer 270. However, the compression of the first protrusion 220b and the adhesive layer 270 is suppressed by the second protrusion 220d and the third protrusion 220e, and the first protrusion 220b and the adhesive layer 270 have the same thickness in the Z-axis direction as the second protrusion 220d and the third protrusion 220e. In this way, the second protrusion 220d and the third protrusion 220e are protrusions that suppress crushing of the first protrusion 220b and the adhesive layer 270.

[0072] [5. Explanation of effects] As described above, in the energy storage device 10 according to the embodiment of the present invention, the spacer 220 includes the first protrusion 220b disposed adjacent to the adhesive layer 270 that bonds the energy storage elements 210 and the spacer 220, and the second protrusion 220d having a protruding height lower than that of the first protrusion 220b. Because the first protrusion 220b is disposed adjacent to the adhesive layer 270, even if the thickness of the adhesive layer 270 varies due to dimensional tolerances of components during assembly of the energy storage device 10, the first protrusion 220b can be crushed to absorb the variation. Furthermore, even if the energy storage elements 210 expand during use of the energy storage device 10, the first protrusion 220b can be crushed to absorb the expansion of the energy storage elements 210. Furthermore, because the spacer 220 includes the second protrusion 220d having a protruding height lower than that of the first protrusion 220b, the second protrusion 220d can prevent the first protrusion 220b from being crushed too much. This makes it possible to maintain an appropriate thickness of the adhesive layer 270 between the energy storage elements 210 and the spacers 220, and to prevent the adhesive layer 270 from being compressed too much or from being subjected to repeated stress in an overly compressed state during assembly and use of the energy storage device 10. This makes it possible to improve the adhesion between the energy storage elements 210 and the spacers 220.

[0073] Furthermore, since the central portion of the energy storage element 210 (the central portion of the long side surface of the container 210a) is prone to swelling, the second protrusion 220d of the spacer 220 is disposed in a position facing the central portion of the energy storage element 210. This can suppress swelling of the central portion of the energy storage element 210, thereby effectively suppressing excessive compression of the adhesive layer 270. Furthermore, by disposing the second protrusion 220d in a position facing the central portion of the energy storage element 210, the adhesive layer 270 is disposed in a position not facing the central portion. Here, the central portion of the energy storage element 210 is prone to repeated expansion and contraction due to charging and discharging. Therefore, by disposing the adhesive layer 270 in a position not facing the central portion, it is possible to suppress repeated stress on the adhesive layer 270 due to expansion and contraction of the energy storage element 210. As a result, the adhesion between the energy storage element 210 and the spacer 220 can be improved.

[0074] Furthermore, since the spacer 220 has two first protrusions 220b at positions sandwiching the adhesive layer 270, it is possible to prevent the adhesive layer 270 from protruding from a predetermined position (between the two first protrusions 220b). As a result, the adhesive layer 270 can be positioned in an appropriate position by the two first protrusions 220b, thereby improving the adhesion between the energy storage element 210 and the spacer 220.

[0075] Furthermore, the spacer 220 has a third protruding portion 220e between the first protruding portion 220b and the second protruding portion 220d, the third protruding portion 220e having a lower protruding height than the first protruding portion 220b. In this way, by disposing the third protruding portion 220e, which has a lower protruding height than the first protruding portion 220b, in addition to the second protruding portion 220d, on the spacer 220, it is possible to further prevent the first protruding portion 220b from being crushed too much. This further prevents the adhesive layer 270 from being compressed too much or from being subjected to repeated stress in an overly compressed state, thereby improving the adhesion between the energy storage element 210 and the spacer 220.

[0076] Furthermore, the portion of the energy storage element 210 facing the flat portion 210f1 of the electrode body 210f is likely to expand with use and is also likely to repeatedly expand and contract due to charging and discharging. For this reason, at least a portion of the adhesive layer 270 is disposed in a position that does not overlap with the flat portion 210f1. This prevents the adhesive layer 270 from being excessively compressed due to the expansion of the energy storage element 210 or from being subjected to repeated stress, thereby improving the adhesion between the energy storage element 210 and the spacer 220.

[0077] Furthermore, in order to prevent swelling of the energy storage element 210, the central portion of the energy storage element 210 (a position corresponding to the flat portion 210f1 of the electrode body 210f) may be recessed during manufacturing, which makes it difficult to bond the central portion of the energy storage element 210 to the spacer 220. For this reason, by arranging the adhesive layer 270 in a position that does not face the central portion (a position that does not overlap with the flat portion 210f1 of the electrode body 210f), the energy storage element 210 and the spacer 220 can be easily bonded together.

[0078] [6 Explanation of Variations] Although the energy storage device 10 according to the embodiment of the present invention has been described above, the present invention is not limited to this embodiment. In other words, the embodiment disclosed herein is illustrative in all respects and is not restrictive, and the scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope equivalent to the claims.

[0079] For example, in the above embodiment, the first protrusion 220b of the spacer 220 is a rectangular annular rib formed to surround the outer periphery of the spacer main body 220a. However, the shape of the first protrusion 220b is not particularly limited and may be a circular, elliptical, or oval annular rib, or may be a linear or curved rib other than a ring, or may be a strip-shaped protrusion. Furthermore, the first protrusion 220b may be disposed in the center or the like of the spacer main body 220a rather than the outer periphery. Furthermore, instead of two first protrusions 220b being disposed on both sides of the adhesive layer disposing portion 220c (or the adhesive layer 270), only one first protrusion 220b may be disposed on one side of the adhesive layer disposing portion 220c (or the adhesive layer 270).

[0080] In the above embodiment, the second protrusion 220d of the spacer 220 is a circular protrusion formed in the center of the spacer main body 220a. However, the shape of the second protrusion 220d is not particularly limited, and may be a shape other than a circle, such as an annular shape such as an annular ring, a polygonal shape, a linear shape, or a curved shape. Furthermore, the second protrusion 220d may be disposed on the outer periphery of the spacer main body 220a, or multiple second protrusions 220d may be disposed on the spacer 220.

[0081] In the above embodiment, the third protrusion 220e of the spacer 220 is a linear rib extending radially from the second protrusion 220d toward the first protrusion 220b. However, the shape of the third protrusion 220e is not particularly limited, and it may be a curved rib, a strip-like protrusion, or the like. Furthermore, the third protrusion 220e may be connected to the first protrusion 220b or not connected to the second protrusion 220d. It may be located anywhere between the first protrusion 220b and the second protrusion 220d, or it may not be located between the first protrusion 220b and the second protrusion 220d. The number of third protrusions 220e is also not particularly limited, and only one third protrusion 220e may be provided. The third protrusion 220e may have a higher or lower protrusion height than the second protrusion 220d. Furthermore, the spacer 220 does not necessarily have to have a third protrusion 220e.

[0082] Furthermore, in the above embodiment, the adhesive layer 270 is arranged over the entire adhesive layer arrangement portion 220c, but the adhesive layer 270 may be arranged only over a portion of the adhesive layer arrangement portion 220c.

[0083] In the above embodiment, the adhesive layer arrangement portion 220c and the adhesive layer 270 are arranged at positions where at least a portion thereof does not overlap the flat portion 210f1 of the electrode body 210f of the energy storage element 210 when viewed from a predetermined direction. However, the entirety of one or both of the adhesive layer arrangement portion 220c and the adhesive layer 270 may be arranged at a position where it overlaps the flat portion 210f1 when viewed from the predetermined direction.

[0084] In the above embodiment, any one of the plurality of spacers 220 (221, 222) may not have the above configuration. Similarly, any one of the plurality of energy storage elements 210 may not have the above configuration.

[0085] Furthermore, the power storage device 10 does not necessarily have to include all of the above-described components. For example, the power storage device 10 does not necessarily have to include the spacer 223, the side plate 243, the bus bar frame 260, the thermistor 252, the mounting member 300, the electrical device 400, the relay 520, or the like.

[0086] Furthermore, configurations constructed by arbitrarily combining the components included in the above-described embodiments and their modifications are also included within the scope of the present invention.

[0087] Furthermore, the present invention can be realized not only as the electricity storage device 10 but also as the spacer 220. [Industrial Applicability]

[0088] The present invention can be applied to an electricity storage device including an electricity storage element such as a lithium ion secondary battery. [Explanation of symbols]

[0089] 10. Energy storage device 100 exterior body 200 Energy Storage Unit 210 Energy storage element 210a container 210a1 container body 210a2 container lid 210b Electrode terminal 210e current collector 210f electrode body 210f1 flat part 210f2 curved section 210f3 connection part 211 First storage element 212 Second storage element 220, 221, 222, 223 spacers 220a Spacer body 220b First protrusion 220c Adhesive layer arrangement part 220d Second protrusion 220e Third protrusion 230, 231, 232 End plates 240, 241, 242, 243 Side Plates 250, 510 busbar 270 Adhesive layer

Claims

1. A storage element that is flat in a predetermined direction; a spacer disposed in the predetermined direction of the energy storage element; an adhesive layer disposed between the energy storage element and the spacer in the predetermined direction and adhering the energy storage element and the spacer together; The spacer is a spacer main body disposed opposite the energy storage element in the predetermined direction; a first protrusion disposed between the energy storage element and the spacer body at a position adjacent to the adhesive layer in a direction intersecting the predetermined direction, the first protrusion protruding from the spacer body toward the energy storage element; a second protruding portion that is disposed at a position different from the first protruding portion between the energy storage element and the spacer body, protrudes from the spacer body toward the energy storage element, and has a protruding height smaller than that of the first protruding portion; Energy storage device.

2. The second protrusion is disposed at a position facing a center portion of the energy storage element. The power storage device according to claim 1 .

3. The spacer has two first protrusions at positions sandwiching the adhesive layer in the cross direction. The electricity storage device according to claim 1 or 2.

4. The spacer further comprises: a third protruding portion disposed between the first protruding portion and the second protruding portion, the third protruding portion having a lower protruding height than the first protruding portion; The electricity storage device according to any one of claims 1 to 3.

5. the energy storage element has an electrode body having a flat portion formed at a position facing the spacer, At least a part of the adhesive layer is disposed at a position that does not overlap the flat portion when viewed from the predetermined direction. The electricity storage device according to any one of claims 1 to 4.

Images