JP7225795B2 - power storage device - Google Patents

Description

The present invention relates to a power storage device including power storage elements and end plates.

2. Description of the Related Art Conventionally, power storage devices including power storage elements and end plates are widely known. For example, Patent Literature 1 discloses a battery module unit (power storage device) including battery cells (power storage elements) and end plates.

JP 2015-109176 A

However, in the power storage device having the conventional structure, the end plate may be damaged. That is, in the power storage device disclosed in Patent Document 1, the end plate is a plate-like member. Therefore, when the power storage element swells with use, a pressing force is generated toward the end plate. The end plate may be deformed and damaged.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a power storage device capable of suppressing damage to end plates.

To achieve the above object, a power storage device according to one aspect of the present invention is a power storage device including a power storage element, comprising: an end plate disposed at an end of the power storage device on a first direction side; a spacer arranged between the element and the end plate, the spacer having an uneven spacer surface facing the end plate and having an uneven spacer shape; It has a plate uneven surface facing the spacer uneven surface and having an uneven shape along the uneven shape of the spacer uneven surface.

According to this, in the power storage device, the spacer between the power storage element and the end plate has the spacer uneven surface on the surface facing the end plate, and the end plate has plate unevenness along the uneven shape of the spacer uneven surface. have a face. Thus, by forming the spacer uneven surface on the spacer and forming the plate uneven surface along the spacer uneven surface on the end plate, the pressing force generated from the spacer toward the end plate can be transferred to the plate via the spacer uneven surface. It can be received on an uneven surface. In other words, when the storage element swells, the pressing force transmitted from the storage element to the end plate via the spacer is received by the uneven surface of the plate via the uneven surface of the spacer, thereby dispersing the pressing force transmitted to the end plate. can. As a result, local application of force to the end plate can be suppressed, so damage to the end plate can be suppressed.

Further, the surface of the spacer facing the storage element may have a shape along the surface of the storage element facing the spacer.

According to this, the surface of the spacer on the storage element side has a shape along the surface of the storage element on the spacer side. In this way, by forming the surface of the spacer on the power storage element side along the power storage element, the force from the power storage element can be distributed and transmitted to the spacer. As a result, the force applied from the spacer to the end plate can be prevented from becoming biased, so damage to the end plate can be further reduced.

Further, the spacer uneven surface has a spacer inclined surface inclined with respect to the first direction,
The uneven plate surface may have a plate inclined surface along the spacer inclined surface.

According to this, the spacer uneven surface of the spacer has a spacer inclined surface, and the plate uneven surface of the end plate has a plate inclined surface along the spacer inclined surface. In this way, by forming the spacer inclined surface on the uneven spacer surface and forming the plate inclined surface along the spacer inclined surface on the plate uneven surface, force is transmitted from the spacer to the end plate via the inclined surface. As a result, the force applied from the spacers to the endplates can be more dispersed, and damage to the endplates can be further suppressed.

At least one of the spacer and the end plate has a protrusion that protrudes toward the other and contacts the other, and a gap is formed between the uneven surface of the spacer and the uneven surface of the plate. It is permissible to assume that

According to this, a gap is formed between the uneven surface of the spacer and the uneven surface of the plate by abutting the projecting portion of at least one of the spacer and the end plate against the other. In this way, even if the spacers are deformed, the spacers do not abut on the end plates for a certain period of time after the power storage element begins to swell, so it is possible to suppress the application of force to the end plates. As a result, even when the power storage element swells greatly, the maximum stress applied from the spacer to the end plate can be reduced, so damage to the end plate can be further suppressed.

At least one of the spacer and the end plate has an insulating layer extending in a second direction intersecting the first direction and in a third direction intersecting the first direction and the second direction. may

According to this, since at least one of the spacer and the end plate has the insulating layer, the energy storage element and the end plate can be easily insulated. In this way, damage to the end plates can be suppressed while insulating the storage element from the end plates.

Further, the end plate has a first plate portion having the uneven plate surface, and a second plate portion arranged on the first direction side of the first plate portion, and the second plate portion is , an attachment portion extending in the first direction and attached to an external member, and at least one of the second plate portion and the attachment portion extends in the third direction intersecting the first direction, It may be arranged at the central position of one plate portion.

According to this, the end plate has a first plate portion having an uneven plate surface and a second plate portion having an attachment portion to be attached to an external member, and the second plate portion and the attachment portion are At least one is arranged at the central position of the first plate portion. Thus, when the second plate portion is arranged at the center position of the first plate portion, the force transmitted from the storage element to the end plate can be received at the center position of the end plate. Further, when the mounting portion is arranged at the central position of the first plate portion, it is possible to reduce the bending moment applied to the mounting portion, which is the portion fixed to the external member. As a result, it is possible to suppress the force applied to the end plate, thereby further suppressing damage to the end plate.

The end plate further includes a third plate portion disposed between the first plate portion and the second plate portion and extending from one end to the other end of the first plate portion in the third direction. may have

According to this, the end plate has a third plate portion extending from one end to the other end of the first plate portion between the first plate portion and the second plate portion. Therefore, the force applied to the second plate portion can be received from one end to the other end of the first plate portion via the third plate portion. As a result, the unevenness of the force applied to the first plate portion can be suppressed, so that damage to the end plates can be further suppressed.

Note that the present invention can be implemented not only as such a power storage device, but also as a spacer and an end plate included in the power storage device.

According to the power storage device of the present invention, damage to the end plates can be suppressed.

1 is a perspective view showing an appearance of a power storage device according to an embodiment; FIG. FIG. 2 is an exploded perspective view showing each component when the power storage device according to the embodiment is exploded; 1 is a perspective view showing a configuration of an electric storage element according to an embodiment; FIG. 4 is a perspective view showing the configuration of an end spacer according to the embodiment; FIG. It is a perspective view showing the structure of the end plate according to the embodiment. It is a perspective view which shows the positional relationship of the end spacer which concerns on embodiment, and an end plate. It is a sectional view showing the physical relationship of the end spacer concerning an embodiment, and an end plate. It is a sectional view showing the physical relationship of the end spacer concerning an embodiment, and an end plate.

Hereinafter, power storage devices according to embodiments (and modifications thereof) of the present invention will be described with reference to the drawings. It should be noted that the embodiments described below represent comprehensive or specific examples. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of constituent elements, manufacturing processes, order of manufacturing processes, and the like shown in the following embodiments are examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in independent claims representing the highest concept will be described as arbitrary constituent elements. Also, in each drawing, dimensions and the like are not strictly illustrated.

In the following description and drawings, the direction in which the storage elements are arranged, the direction in which the spacers (intermediate spacers and end spacers) are arranged, the direction in which the end plates are arranged, the direction in which the storage elements, the spacers, and the end plates are arranged, and the direction in which one storage element is arranged The opposite direction of the pair of long sides of the container, or the thickness direction of the storage element, spacer, or end plate is defined as the X-axis direction. The Y-axis direction is defined as the direction in which the container body and the lid of the storage element are arranged, or the direction in which the storage element and the bus bar are arranged. The direction in which a pair of electrode terminals in one storage element are aligned, the direction in which a pair of short sides of a container of one storage element face each other, the direction in which side plates are aligned, the direction in which insulating plates are aligned, the direction in which side plates and insulating plates are aligned, Alternatively, the vertical direction is defined as the Z-axis direction. These X-axis direction, Y-axis direction, and Z-axis direction are directions that cross each other (perpendicularly in this embodiment). Although the Z-axis direction may not be the vertical direction depending on the mode of use, the Z-axis direction will be described below for convenience of explanation. Further, in the following description, for example, the positive direction of the X-axis indicates the direction of the arrow of the X-axis, and the negative direction of the X-axis indicates the opposite direction to the positive direction of the X-axis. The same applies to the Y-axis direction and the Z-axis direction. Furthermore, hereinafter, the X-axis direction (or X-axis plus direction) is also called the first direction, the Y-axis direction is also called the second direction, and the Z-axis direction is also called the third direction.

(Embodiment)
[1 General description of power storage device 10]
First, the configuration of power storage device 10 will be described. FIG. 1 is a perspective view showing the appearance of power storage device 10 according to the present embodiment. FIG. 2 is an exploded perspective view showing each component when power storage device 10 according to the present embodiment is exploded.

Power storage device 10 is a device capable of charging electricity from the outside and discharging electricity to the outside, and has a substantially rectangular parallelepiped shape in the present embodiment. For example, the power storage device 10 is a battery module (assembled battery) used for power storage or power supply. Specifically, the power storage device 10 is, for example, an electric vehicle (EV), a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV) such as an automobile, a motorcycle, a watercraft, a snowmobile, an agricultural machine, a construction Used as a stationary battery or the like for driving machines or moving bodies such as railway vehicles for electric railways such as trains, monorails, and linear motor cars, or for starting engines, or for home use or generators. be done.

As shown in FIGS. 1 and 2, power storage device 10 includes a plurality of (16 in this embodiment) power storage elements 100, a plurality of (15 in this embodiment) intermediate spacers 200, and a pair of end spacers 200. A spacer 300 , a pair of end plates 400 , a pair of insulating plates 600 , a pair of side plates 700 and a busbar 800 are provided. Further, an adhesive layer 510 is arranged between the adjacent storage elements 100 , an adhesive layer 520 is arranged between the storage element 100 and the end spacer 300 , and between the storage element 100 and the insulating plate 600 An adhesive layer 530 is disposed. A pair of external terminals 910 (a positive electrode external terminal and a negative electrode external terminal), which are terminals of the power storage device 10 , are arranged on the end spacer 300 . Power storage device 10 includes a busbar frame holding busbar 800, wiring for voltage measurement of power storage element 100, wiring for temperature measurement, a thermistor, a circuit board for monitoring the state of charge and the state of discharge of power storage element 100, and the like. An electric device such as a relay may also be provided.

The storage element 100 is a secondary battery (single battery) capable of charging and discharging electricity, and more specifically, a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The power storage element 100 has a flattened rectangular parallelepiped (square) shape, and is laid down so that the long side faces the X-axis direction and the electrode terminals face the Y-axis plus direction. arranged in a direction. Moreover, the storage element 100 is arranged adjacent to the intermediate spacer 200 or the end spacer 300 . That is, each of the plurality of power storage elements 100 is alternately arranged with each of the plurality of intermediate spacers 200 and the pair of end spacers 300 and arranged in the X-axis direction. In the present embodiment, 15 intermediate spacers 200 are arranged between adjacent energy storage elements 100 among the 16 energy storage elements 100, and the end energy storage elements 100 of the 16 energy storage elements 100 A pair of end spacers 300 are arranged at positions sandwiching the . A detailed description of the configuration of this storage element 100 will be given later.

The number of power storage elements 100 is not particularly limited, and may be a plurality other than 16, or may be one. In addition, the shape of the power storage element 100 is not particularly limited, and may be any shape other than a rectangular parallelepiped shape, such as a polygonal columnar shape, a cylindrical shape, an elliptical columnar shape, an oval columnar shape, or a laminate type power storage device. It can also be used as an element. Moreover, the storage element 100 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, or may be a capacitor. Also, the storage device 100 may be a primary battery that allows the stored electricity to be used without being charged by the user, instead of a secondary battery. Furthermore, the storage element 100 may be a battery using a solid electrolyte.

The intermediate spacers 200 and the end spacers 300 are arranged on the sides of the power storage element 100 (the positive direction of the X axis or the negative direction of the X axis) to insulate the power storage element 100 from other members and prevent the power storage element 100 from swelling. It is a spacer that suppresses the Intermediate spacer 200 and end spacer 300 are made of, for example, polycarbonate (PC), polypropylene (PP), polyethylene (PE), polyphenylene sulfide resin (PPS), polyethylene terephthalate (PET), polyetheretherketone (PEEK), tetrafluoro Insulating resin materials such as ethylene perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polybutylene terephthalate (PBT), polyether sulfone (PES), ABS resin, and composite materials thereof formed. Note that the intermediate spacer 200 and the end spacer 300 may be made of a material other than resin as long as it has insulating properties. It may be formed of a mica plate or the like formed of a material. Also, not all of the intermediate spacers 200 and the pair of end spacers 300 need to be made of the same material.

The intermediate spacer 200 is a rectangular plate-like spacer arranged at the center position of the energy storage element 100 in the Y-axis direction between two adjacent energy storage elements 100 . Adhesive layers 510 such as double-sided tape are arranged on both sides of the intermediate spacer 200 in the Y-axis direction, and the storage elements 100 on both sides of the intermediate spacer 200 in the X-axis direction are adhered by the adhesive layer 510 . Thus, the intermediate spacer 200 is sandwiched between the energy storage elements 100 on both sides in the X-axis direction and fixed to the energy storage elements 100 on both sides in the X-axis direction. In this embodiment, 15 intermediate spacers 200 are arranged corresponding to 16 power storage elements 100. However, if the number of power storage elements 100 is other than 16, the number of intermediate spacers 200 is is also changed according to the number of power storage elements 100 .

The end spacer 300 is a rectangular and plate-shaped spacer arranged between the end storage element 100 and the end plate 400 . Since the end spacer 300 is made of an insulating material as described above, it functions as an insulating layer extending in the Y-axis direction (second direction) and the Z-axis direction (third direction). Also, the end spacer 300 is a member having higher elastic performance (lower Young's modulus or lower rigidity) than the end plate 400 . An adhesive layer 520 such as a double-sided tape is arranged on the end spacer 300 on the storage element 100 side. A detailed description of the configuration of the end spacer 300 will be given later.

The end plate 400 and the side plate 700 are members that press the power storage elements 100 from the outside in the direction in which the power storage elements 100 are arranged (the X-axis direction). That is, the end plates 400 and the side plates 700 sandwich the plurality of power storage elements 100 from both sides in the alignment direction, thereby pressing the power storage elements 100 included in the plurality of power storage elements 100 from both sides in the alignment direction.

Specifically, the end plates 400 are arranged on both sides of the plurality of power storage elements 100 in the X-axis direction, and sandwich the plurality of power storage elements 100 from both sides in the direction in which the plurality of power storage elements 100 are arranged (X-axis direction). It is a plate-shaped member (also called a clamping member) to hold. The end plate 400 is made of a metallic (conductive) material such as stainless steel, iron, plated steel plate, aluminum, aluminum alloy, etc., from the viewpoint of ensuring strength. The material of the end plate 400 is not particularly limited. For example, the end plate 400 may be formed of an insulating material with high strength, or may be subjected to an insulating treatment. A detailed description of the configuration of the end plate 400 will be given later.

The side plate 700 is an elongated plate-shaped member (also referred to as a binding member or a binding bar) having both ends attached to the end plates 400 and binding the plurality of power storage elements 100 . That is, the side plate 700 is arranged so as to extend in the X-axis direction so as to straddle the plurality of storage elements 100, the plurality of intermediate spacers 200, and the pair of end spacers 300. is applied in the direction of arrangement (X-axis direction). In the present embodiment, two side plates 700 are arranged on both sides in the Z-axis direction of the plurality of power storage elements 100 at positions sandwiching the insulating plate 600 with the power storage elements 100 . Each of the two side plates 700 is attached to the Z-axis direction end portions of the two end plates 400 at both X-axis direction end portions. As a result, the two side plates 700 sandwich and constrain the plurality of power storage elements 100 and the like from both sides in the X-axis direction and both sides in the Z-axis direction.

Also, the side plate 700 is fixed to the end plate 400 by a plurality of fixing members 701 such as bolts arranged in the Y-axis direction. The attachment of the side plate 700 to the end plate 400 is not limited to fixing with bolts or the like, and may be fixed (joined) by welding, adhesion, riveting, caulking, or the like. The side plate 700 may be made of any material, but is made of the same material as the end plate 400 from the viewpoint of securing strength, for example. Also, the side plate 700 may be a block-shaped or rod-shaped member or the like.

The insulating plates 600 are long flat insulating members (insulators) arranged on both sides of the plurality of power storage elements 100 in the Z-axis direction and extending in the X-axis direction. That is, the insulating plate 600 is arranged between the plurality of power storage elements 100 and the like and the side plate 700 so as to straddle the plurality of power storage elements 100 , the plurality of intermediate spacers 200 and the pair of end spacers 300 . and the side plate 700 are insulated. Here, an adhesive layer 530 such as a double-sided tape is arranged between the storage element 100 and the insulating plate 600 , and the storage element 100 and the insulating plate 600 are adhered by the adhesive layer 530 . The insulating plate 600 may be made of any material as long as it is an insulating member, but is made of the same material as the intermediate spacer 200 and the end spacer 300, for example. Note that the two insulating plates 600 may be made of different materials.

The bus bar 800 is a conductive plate-like member arranged on the plurality of storage elements 100 and electrically connecting the electrode terminals of the plurality of storage elements 100 . In the present embodiment, bus bar 800 connects a plurality of power storage elements 100 in series by sequentially connecting the positive terminals and negative terminals of adjacent power storage elements 100 . In addition, external terminals 910 on the positive electrode side and the negative electrode side are connected to bus bars 800 arranged at the ends. The busbar 800 is made of a conductive member made of metal such as aluminum, aluminum alloy, copper, copper alloy, or the like. The connection form of the storage elements 100 is not particularly limited, and any one of the storage elements 100 may be connected in parallel.

[2 Detailed Description of Electricity Storage Element 100]
Next, the configuration of the storage element 100 will be described in detail. FIG. 3 is a perspective view showing the structure of the storage device 100 according to this embodiment. Specifically, FIG. 3 is an enlarged perspective view showing a state in which the intermediate spacer 200 and the adhesive layers 510, 520, 530 are removed from the storage element 100 in FIG. In addition, since all the 16 electric storage elements 100 in FIG. 2 have the same configuration, one electric storage element 100 will be described below.

As shown in FIG. 3, the electric storage element 100 includes a container 110, a pair of electrode terminals 120 (a positive electrode terminal and a negative electrode terminal), and a pair of gaskets 130 (a positive electrode side gasket and a negative electrode side gasket). Further, an electrode assembly, a pair of current collectors (a positive electrode current collector and a negative electrode current collector), an electrolytic solution (non-aqueous electrolyte), and the like are housed inside the container 110, but these are not shown in the drawing. are omitted. There is no particular limitation on the type of the electrolytic solution as long as it does not impair the performance of the storage element 100, and various types can be selected. Gaskets are also arranged between the container 110 (cover 112 to be described later) and the current collector, and spacers are arranged on the sides of the current collector, etc., but illustration of these is omitted.

The container 110 is a rectangular parallelepiped (square) container having a container body 111 having an opening, a lid 112 closing the opening of the container body 111, and an insulating sheet 113 covering the outer surface of the container body 111. be. The container main body 111 is a rectangular tubular member that constitutes the main body of the container 110 and has a bottom. The lid body 112 is a rectangular plate-shaped member that constitutes the lid portion of the container 110 , and is arranged to extend in the Z-axis direction on the Y-axis plus direction side of the container body 111 . The lid 112 has a gas discharge valve 112a that releases the pressure inside the container 110 when the pressure rises, and a liquid injection part (not shown) for injecting an electrolytic solution into the container 110. etc. are provided. Although the material of the container body 111 and the lid 112 is not particularly limited, it is preferably a weldable metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel plate.

The insulating sheet 113 is an insulating sheet-like member arranged on the outer surface of the container body 111 to cover the outer surface of the container body 111 . The material of the insulating sheet 113 is not particularly limited as long as it can ensure the insulation required for the power storage element 100. Examples include insulating resins such as PC, PP, PE, PPS, PET, PBT, and ABS resin; Epoxy resin, Kapton, Teflon (registered trademark), silicone, polyisoprene, and polyvinyl chloride can be exemplified.

In this manner, the electrode body and the like are accommodated inside the container body 111, the container body 111 and the lid body 112 are joined by welding or the like to seal the inside, and the insulating sheet 113 is arranged on the outer surface of the container body 111. A container 110 is formed at the end. Thus, the container 110 has a pair of long side portions 110a on both sides in the X-axis direction, a pair of short side portions 110b on both sides in the Z-axis direction, and a bottom portion 110c on the Y-axis minus direction side. It is configured to have The long side surface portion 110a is a rectangular flat surface portion forming the long side surface of the container 110, the short side surface portion 110b is a rectangular flat surface portion forming the short side surface of the container 110, and the bottom surface portion 110c is a rectangular flat surface portion forming the short side surface of the container 110. It is a rectangular planar portion forming the bottom surface of 110 . In this embodiment, the insulating sheet 113 is disposed on all of the pair of long side portions 110a, the pair of short side portions 110b, and the bottom portion 110c, but is not disposed on the bottom portion 110c. A configuration in which they are not arranged on any of the surface portions is also possible.

The electrode terminals 120 are terminals (a positive terminal and a negative terminal) of the power storage element 100 arranged on the lid 112, and are electrically connected to the positive plate and the negative plate of the electrode body via current collectors. . In other words, the electrode terminal 120 is made of metal for leading electricity stored in the electrode body to the external space of the storage element 100 and for introducing electricity into the internal space of the storage element 100 to store the electricity in the electrode body. It is a member made of The electrode terminal 120 is made of aluminum, an aluminum alloy, copper, a copper alloy, or the like. The gasket 130 is a member arranged around the electrode terminal 120 and between the electrode terminal 120 and the lid 112 to ensure insulation and airtightness between the electrode terminal 120 and the lid 112. . The gasket 130 is made of an insulating material such as PP, PE, PPS, PET, PEEK, PFA, PTFE, PBT, PES, and ABS resin.

The electrode assembly is a power storage element (power generation element) formed by laminating a positive electrode plate, a negative electrode plate, and a separator. Here, the positive electrode plate included in the electrode assembly is formed by forming a positive electrode active material layer on a positive electrode base material layer, which is a long belt-shaped collector foil made of a metal such as aluminum or an aluminum alloy. Further, the negative electrode plate is formed by forming a negative electrode active material layer on a negative electrode base material layer, which is a long belt-shaped collector foil made of a metal such as copper or a copper alloy. As the positive electrode active material used for the positive electrode active material layer and the negative electrode active material used for the negative electrode active material layer, known materials can be appropriately used as long as they can intercalate and deintercalate lithium ions. The current collectors are members (positive electrode current collector and negative electrode current collector) having conductivity and rigidity electrically connected to the electrode terminal 120 and the electrode body. The positive electrode current collector is made of aluminum or an aluminum alloy like the positive electrode substrate layer of the positive electrode plate, and the negative electrode current collector is made of copper or a copper alloy like the negative electrode substrate layer of the negative electrode plate. It is

[3 Detailed Description of End Spacer 300]
Next, the configuration of the end spacer 300 will be described in detail. FIG. 4 is a perspective view showing the configuration of the end spacer 300 according to this embodiment. Specifically, FIG. 4 is a perspective view showing the end spacer 300 on the positive direction side of the X axis in FIG. 2 together with the terminal member 900 having the external terminal 910 . In FIG. 2, the end spacer 300 on the side of the X-axis plus direction and the end spacer 300 on the side of the X-axis minus direction have symmetrical shapes with respect to the YZ plane. A description of the spacer 300 is omitted.

As shown in FIG. 4 , the end spacer 300 has a spacer body portion 310 , a terminal block 320 and a spacer projection portion 330 . The spacer main body portion 310 is a plate-like portion that constitutes the main body portion of the end spacer 300. The spacer main body portion 310 has a spacer uneven surface 310a having an uneven shape on the surface on the positive side of the X axis, and the surface on the negative side of the X axis. It has a flat (planar shape) spacer flat surface 310b.

Here, the spacer body portion 310 has a spacer convex portion 311 , a spacer concave portion 312 and a spacer inclined portion 313 . The spacer convex portion 311 is a convex portion of the spacer main body portion 310 that protrudes in the positive direction of the X axis, and is located at the end of the spacer main body portion 310 on the positive side of the Z axis, the end on the negative side of the Z axis, and Three spacer projections 311 located in the center in the Z-axis direction are arranged to extend in the Y-axis direction. The spacer recessed portion 312 is a recessed portion of the spacer body portion 310 that is recessed in the negative direction of the X-axis, and is located between two adjacent spacer projecting portions 311 out of the three spacer projecting portions 311 . 312 are arranged extending in the Y-axis direction. The spacer inclined portions 313 are gently inclined from the spacer convex portions 311 to the spacer concave portions 312. The four spacer inclined portions 313 positioned between the respective spacer convex portions 311 and the spacer concave portions 312 , are arranged to extend in the Y-axis direction.

Specifically, the spacer convex portion 311 is formed with a plurality of recessed portions 311a that are recessed in the negative direction of the X-axis and arranged in the direction of the Y-axis. Moreover, it has a shape provided with a plurality of ribs 311b arranged in the Y-axis direction. A spacer convex surface 311c is formed by arranging the tip surfaces (surfaces on the positive side of the X-axis) of the plurality of ribs 311b. That is, the spacer convex surface 311c is a surface of the spacer convex portion 311 on the X-axis plus direction side, and is a plane parallel to the YZ plane in which a plurality of holes are formed.

Similarly, the spacer recessed portion 312 is formed with a plurality of recessed portions 312a that are recessed in the negative X-axis direction and are aligned in the Y-axis direction and the Z-axis direction. Moreover, it has a shape provided with a plurality of ribs 312b arranged in the Y-axis direction. A spacer concave surface 312c is formed by arranging the tip surfaces (surfaces on the positive side of the X-axis) of the plurality of ribs 312b. That is, the spacer concave surface 312c is a surface on the X-axis positive direction side of the spacer concave surface 312 and is a plane parallel to the YZ plane in which a plurality of holes are formed.

The spacer inclined portion 313 is a portion that connects the spacer convex portion 311 and the spacer concave portion 312 . That is, the spacer inclined portion 313 is connected to the spacer convex portion 311 at the end on the Z-axis positive direction side, and is connected to the spacer concave portion 312 on the Z-axis negative direction side, and gradually changes from a convex portion to a concave portion. It has a slanted shape. As a result, the spacer inclined portion 313 is formed with a spacer inclined surface 313a connecting the spacer convex surface 311c and the spacer concave surface 312c. That is, the spacer inclined surface 313a is a surface on the X-axis positive direction side of the spacer inclined portion 313, and is an inclined surface inclined with respect to the X-axis direction (first direction) in which the plurality of holes are formed. Specifically, the spacer inclined surface 313a is an inclined surface inclined from the X-axis direction to the Z-axis plus direction or the Z-axis minus direction.

In this way, the spacer uneven surface 310a has the spacer convex surface 311c, the spacer concave surface 312c, and the spacer inclined surface 313a, so that the spacer uneven surface 310a has a wavy shape that undulates in the Z-axis direction. are doing.

Moreover, the spacer body portion 310 further has two spacer-side fitting portions 314 arranged in the Y-axis direction. The spacer-side fitting portion 314 is a cylindrical portion that protrudes from the spacer uneven surface 310a in the positive direction of the X axis, and is inserted into a through-hole 412a (described later) formed in the end plate 400 to be fitted. , to fix the end spacer 300 to the end plate 400 .

The terminal block 320 is a pedestal portion provided at the end portion of the end spacer 300 on the Y-axis plus direction side, on which the external terminal 910 is arranged. In the present embodiment, a terminal member 900 having external terminals 910 and bus bars 920 connected to power storage elements 100 is insert-molded into terminal block 320 and formed integrally with terminal block 320 .

The spacer projecting portion 330 is accommodated in a recess formed in the spacer uneven surface 310a of the spacer main body portion 310, and a part on the X-axis positive direction side projects from the spacer uneven surface 310a in the X-axis positive direction. It is a cylindrical member (see FIG. 7). Specifically, the spacer protrusion 330 is a collar to which the fixing member 701 is fastened to fix the side plate 700 to the end spacer 300 and the end plate 400 . In the present embodiment, three spacer projecting portions 330 are arranged side by side in the Y-axis direction at the ends of the spacer body portion 310 on the Z-axis plus direction side and the Z-axis minus direction side, respectively.

Note that the shape of the spacer projecting portion 330 is not particularly limited, and may be any shape such as an oval shape, an elliptical shape, a cylindrical shape such as a polygonal shape, or a columnar shape when viewed from the positive direction of the X-axis. The number of spacer projections 330 is also not limited. The spacer protruding portion 330 may be a portion of the spacer body portion 310 that protrudes in the positive direction of the X axis from the uneven spacer surface 310a instead of the collar. may That is, at least one of the end spacer 300 and the end plate 400 should have a protruding portion that protrudes toward the other and contacts the other.

[4 Detailed Description of End Plate 400]
Next, the configuration of the end plate 400 will be described in detail. FIG. 5 is a perspective view showing the configuration of the end plate 400 according to this embodiment. Specifically, FIG. 5 is an exploded perspective view showing the exploded end plate 400 on the positive direction side of the X axis in FIG. In FIG. 2, the end plate 400 on the X-axis plus direction side and the end plate 400 on the X-axis minus direction side have the same configuration, so the end plate 400 on the X-axis minus direction side will be described. are omitted.

As shown in FIG. 5 , the end plate 400 has a first plate portion 410 , a second plate portion 420 and a third plate portion 430 . The first plate portion 410 is a corrugated plate-like member arranged on the X-axis plus direction side (first direction side) of the end spacer 300 . The second plate portion 420 is a plate-like member arranged on the X-axis plus direction side (first direction side) of the first plate portion 410 . The third plate portion 430 is a plate-like member arranged between the first plate portion 410 and the second plate portion 420 in the X-axis direction. That is, the third plate portion 430 is arranged on the X-axis positive direction side of the first plate portion 410 , and the second plate portion 420 is arranged on the X-axis positive direction side of the third plate portion 430 .

Specifically, the first plate portion 410 has a plate concave portion 411 , a plate convex portion 412 and a plate inclined portion 413 . The plate recessed portion 411 is a recessed portion of the first plate portion 410 that is recessed in the positive direction of the X-axis. Three plate recesses 411 located in the center in the Z-axis direction are arranged to extend in the Y-axis direction. The plate convex portion 412 is a convex portion of the first plate portion 410 that protrudes in the negative direction of the X axis, and two plates positioned between two adjacent plate concave portions 411 out of the three plate concave portions 411. A convex portion 412 is arranged to extend in the Y-axis direction. The plate slanted portion 413 is a portion that is gently slanted from the plate recess 411 toward the plate protrusion 412. The four plate slopes 413 positioned between the plate recess 411 and the plate protrusion 412 , are arranged to extend in the Y-axis direction.

The plate recess 411 at the end on the Z-axis positive direction side is formed with three openings 411a into which the three spacer projecting portions 330 arranged on the Z-axis positive direction side of the end spacer 300 are inserted. . Similarly, the plate recess 411 at the end on the Z-axis negative direction side is formed with three openings 411a into which the three spacer projecting portions 330 arranged on the Z-axis negative direction side of the end spacer 300 are inserted. there is Furthermore, two through-holes 412a into which the two spacer-side fitting portions 314 of the end spacer 300 are inserted and fitted are formed in the plate convex portion 412 on the Z-axis positive direction side.

The third plate portion 430 extends from one end of the first plate portion 410 to the other end in the Z-axis direction (third direction), and extends from one end of the first plate portion 410 in the Y-axis direction. It is a rectangular and flat plate-shaped member that extends from the end to the other end. Three through-holes 431 into which the fixing member 701 is inserted are formed in the third plate portion 430 at the end on the positive side of the Z-axis and the end on the negative side of the Z-axis. Furthermore, the third plate portion 430 is formed with two through holes 432 for preventing interference with the two spacer-side fitting portions 314 .

The second plate portion 420 is arranged at the center position of the first plate portion 410 (that is, the center position of the third plate portion 430) in the Z-axis direction (third direction), and is located at the center position of the third plate portion 430 in the Y-axis direction. It is a plate-shaped member that extends from one end of the portion 430 to the other end. Here, the second plate portion 420 includes a second plate main body portion 421 attached to a central position of the third plate portion 430, and a second plate main body portion 421 extending in the X-axis direction (first direction). and an attachment portion 422 attached to a member of the . The second plate main body portion 421 is a rectangular flat plate-like portion that is parallel to the YZ plane and elongated in the Y-axis direction. The mounting portion 422 is a rectangular flat plate-like portion that is parallel to the XY plane and elongated in the Y-axis direction. That is, the attachment portion 422 has a shape that is bent from the second plate body portion 421 toward the X-axis direction. The attachment portion 422 is formed with three through holes 422a arranged in the Y-axis direction, which are used when the attachment portion 422 is attached to an external member.

[5 Description of positional relationship between end spacer 300 and end plate 400]
Next, the positional relationship between the end spacers 300 and the end plates 400 will be described in detail. FIG. 6 is a perspective view showing the positional relationship between the end spacer 300 and the end plate 400 according to this embodiment. Specifically, FIG. 6 is a perspective view showing the configuration when the end spacer 300 and the end plate 400 on the positive direction side of the X axis in FIG. 2 are assembled. 7 and 8 are cross-sectional views showing the positional relationship between the end spacer 300 and the end plate 400 according to this embodiment. Specifically, FIG. 7 is a cross-sectional view showing the configuration when the configuration in FIG. 6 is cut along the VII-VII cross section, and FIG. 8 is the configuration when the configuration in FIG. 6 is cut along the VIII-VIII cross section. It is a cross-sectional view showing the. In addition, in FIGS. 7 and 8, the positions of the storage elements 100 are indicated by dashed lines. Note that the configuration on the negative side of the X axis in FIG. 2 is the same, so the description is omitted.

As shown in these figures, the end spacer 300 is arranged on the X-axis positive direction side (first direction side) of the power storage element 100 , and the end plate 400 is arranged on the X-axis positive direction side (first direction side) of the end spacer 300 . side). That is, the end plate 400 is arranged at the end of the power storage device 10 on the X-axis plus direction side (first direction side), and the end spacer 300 is arranged between the power storage element 100 and the end plate 400 .

With such a configuration, the spacer uneven surface 310 a of the end spacer 300 is arranged to face the first plate portion 410 of the end plate 400 . That is, the first plate portion 410 has a plate uneven surface 410a that faces the spacer uneven surface 310a and has an uneven shape that follows the uneven shape of the spacer uneven surface 310a. Specifically, the plate uneven surface 410a has a plate concave surface 411b, a plate convex surface 412b, and a plate inclined surface 413a. have.

The plate concave surface 411b is the surface of the plate concave portion 411 of the first plate portion 410 on the X-axis negative direction side, and is a plane parallel to the YZ plane along the spacer convex surface 311c. The plate convex surface 412b is a surface on the X-axis negative direction side of the plate convex portion 412, and is a plane parallel to the YZ plane along the spacer concave surface 312c. The plate inclined surface 413a is a surface on the X-axis negative direction side of the plate inclined portion 413, and is an inclined surface along the spacer inclined surface 313a. The spacer inclined surface 313a and the plate inclined surface 413a are preferably inclined at an angle of 15° or more and 75° or less with respect to the X-axis direction, and are inclined at an angle of 30° or more and 60° or less. is more preferable, and it is even more preferable to incline at an angle of 40° or more and 50° or less.

The spacer projecting portion 330 is arranged in contact with the end plate 400, thereby forming a gap between the spacer uneven surface 310a and the plate uneven surface 410a. Specifically, the spacer projecting portion 330 passes through an opening 411 a formed in the first plate portion 410 of the end plate 400 and is arranged in contact with the third plate portion 430 . A gap is formed between the spacer convex surface 311c, the spacer concave surface 312c and the spacer inclined surface 313a and the plate concave surface 411b, the plate convex surface 412b and the plate inclined surface 413a.

Spacer flat surface 310 b of end spacer 300 is arranged to face storage element 100 . That is, the spacer flat surface 310 b is the surface of the end spacer 300 facing the storage element 100 and has a shape along the surface of the storage element 100 facing the end spacer 300 . Thereby, the spacer flat surface 310 b is adhered to the storage element 100 by the adhesive layer 520 . In the present embodiment, since the long side portion 110a of the container 110 of the storage element 100 is flat, the end spacer 300 has a flat spacer flat surface 310b. It is sufficient that the surface has a shape corresponding to the shape of the container 110 . In other words, when the long side portion 110a of the storage element 100 is curved instead of flat, the end spacer 300 may have a curved surface along the long side portion 110a on the storage element 100 side.

Since the second plate portion 420 is arranged at the center position of the first plate portion 410 in the Z-axis direction, the mounting portion 422 is also arranged at the center position of the first plate portion 410 . Here, the central position of the first plate portion 410 is, for example, a position corresponding to the central three portions when the first plate portion 410 is divided into five in the Z-axis direction. With this configuration, both ends of the end plate 400 in the Z-axis direction are supported by the first plate portion 410, and the central portion in the Z-axis direction is supported by the second plate portion 420. is about 2/3 of the case where the Z-axis direction end of is supported by the second plate portion 420 . Thereby, an increase in the plate thickness of the end plate 400 can be suppressed. Thus, at least one of the second plate portion 420 and the attachment portion 422 is arranged at the center position of the first plate portion 410 in the Z-axis direction (third direction).

In addition, it is more preferable that the central position of the first plate portion 410 is a position corresponding to the central two portions when the first plate portion 410 is divided into four. In this case, the generated stress is about 1/2 of that when the Z-axis direction end portion of the end plate 400 is supported by the second plate portion 420 . Further, it is more preferable to set the position corresponding to the central portion when the first plate portion 410 is divided into three. In this case, the generated stress is about 1/3 of that when the Z-axis direction end portion of the end plate 400 is supported by the second plate portion 420 .

[6 Explanation of effects]
As described above, according to power storage device 10 according to the present embodiment, end spacer 300 has spacer uneven surface 310a on the surface facing end plate 400, and end plate 400 has spacer uneven surface 310a. It has a plate uneven surface 410a along the shape. By forming the spacer uneven surface 310a on the end spacer 300 and forming the plate uneven surface 410a on the end plate 400 in this manner, the pressing force generated from the end spacer 300 toward the end plate 400 is applied to the spacer uneven surface 310a. It can be received by the uneven plate surface 410a through the plate. That is, when the energy storage element 100 swells, the pressing force transmitted from the energy storage element 100 to the end plate 400 via the end spacer 300 is received by the plate uneven surface 410a via the spacer uneven surface 310a. The transmitted pressing force can be dispersed. As a result, local force applied to the end plate 400 can be suppressed, and damage to the end plate 400 can be suppressed. If damage to the end plate 400 can be suppressed, an increase in the plate thickness of the end plate 400 can be suppressed, so weight reduction and space saving can be achieved.

Moreover, the surface of the end spacer 300 on the power storage element 100 side has a shape along the surface of the power storage element 100 on the end spacer 300 side. By shaping the surface of the end spacer 300 on the power storage element 100 side along the power storage element 100 in this way, the force from the power storage element 100 can be distributed and transmitted to the end spacer 300 . As a result, the force applied from the end spacers 300 to the end plate 400 can be prevented from being biased, so damage to the end plate 400 can be further reduced. Specifically, it is as follows.

In power storage device 10, end spacer 300 is provided with spacer uneven surface 310a, and end plate 400 is provided with plate uneven surface 410a. 310a can be received on the plate uneven surface 410a. Thereby, the pressing force transmitted to the end plate 400 can be dispersed. Here, in order to disperse and transmit the pressing force generated by the expansion of the power storage element 100 to the end plates 400, when the pressing force is transmitted to the end spacers 300, which are intermediates, It is desirable to have the load distributed as much as possible.

Conventionally, the shape of the long side of an electric storage element varies due to manufacturing variations, such as an overall concave shape, a substantially flat shape, and an overall bulging shape. For this reason, some end spacers are provided with crushing ribs. However, there is a growing tendency to pack electrode bodies into energy storage elements due to the demand for improved energy density. In such a case, if an end spacer provided with a crushing rib is used, the pressing force will be concentrated on the rib portion even in normal times, and if swelling occurs in the storage element, this tendency will become even stronger. That is, when the pressing force generated by the swelling of the storage element is transmitted to the end spacers, the pressing force concentrates on the portion where the crushing ribs are installed, making it difficult to disperse the pressing force.

In addition, there is also a form in which an end spacer having a structure in which a ventilation passage is provided is employed in order to send cooling air between the storage element and the storage element. In such a configuration, the pressing force generated when the storage element swells is first consumed by collapsing the ventilation passage between the storage element and the storage element provided by the end spacers. That is, the tendency of the pressing force to disperse depends on the shape of the ventilation passage, and the structure is not always optimized in terms of the transmission of the pressing force.

In other words, in order to distribute the pressing force to the end spacers 300 as much as possible, the surface of the end spacer 300 on the storage element 100 side has a shape that follows the surface of the storage element 100 on the end spacer 300 side. is most desirable. As a result, the pressing force generated by the swelling of the power storage element 100 becomes a distributed load when it is transmitted to the end spacer 300, which is an intermediate inclusion, and presses the plate uneven surface 410a via the spacer uneven surface 310a. can be transmitted in a more distributed manner.

The spacer uneven surface 310a of the end spacer 300 has a spacer inclined surface 313a, and the plate uneven surface 410a of the end plate 400 has a plate inclined surface 413a along the spacer inclined surface 313a. In this manner, the spacer inclined surface 313a is formed on the spacer uneven surface 310a, and the plate inclined surface 413a is formed along the spacer inclined surface 313a on the plate uneven surface 410a. Power is transmitted through As a result, the force applied from the end spacers 300 to the end plates 400 can be more dispersed, so damage to the end plates 400 can be further suppressed.

Specifically, it is as follows. Since the end spacer 300 has the spacer uneven surface 310a and the end plate 400 has the plate uneven surface 410a, the contact area between the end spacer 300 and the end plate 400 increases, and the pressing force per unit area decreases. do. As a result, the force applied to the end plate 400 can be received in a more dispersed manner, and damage to the end plate 400 can be further suppressed. Further, the spacer uneven surface 310a has the spacer inclined surface 313a, and the plate uneven surface 410a has the plate inclined surface 413a. It is possible to generate a component force along. As a result, the pressing force acting on the end plate 400 as a horizontal force component can be further reduced, and damage to the end plate 400 can be further suppressed.

At least one projection (spacer projection 330) of the end spacer 300 and the end plate 400 contacts the other, so that a gap is formed between the spacer uneven surface 310a and the plate uneven surface 410a. there is In this way, even if the end spacers 300 are deformed, the end spacers 300 do not abut on the end plates 400 for a certain period of time after the power storage element 100 starts to swell. can. As a result, even when the power storage element 100 swells greatly, the maximum stress applied from the end spacers 300 to the end plates 400 can be reduced, so damage to the end plates 400 can be further suppressed.

Specifically, it is as follows. When the end spacer 300 and the end plate 400 are in contact with each other from the beginning, the load is transmitted to the end plate 400 immediately after the power storage element 100 begins to swell. converted to force. On the other hand, if a certain gap is formed between the end spacer 300 and the end plate 400, the energy is consumed by eating up the gap when the power storage element 100 starts to swell, so the load is propagated to the end plate 400 as a load. never Then, the gap is eaten up, and from the time when the end spacer 300 and the end plate 400 start coming into contact with each other, the load is transmitted to the end plate 400 . In other words, when comparing the amount of swelling of the same storage element 100, swelling occurs more in the end plate 400 when a certain gap is formed than when the end spacer 300 and the end plate 400 are in contact from the beginning. The maximum load to be applied can be reduced. Thereby, damage to the end plate 400 can be further suppressed.

At least one of the end spacers 300 and the end plates 400 has an insulating layer (in the present embodiment, the end spacers 300 function as insulating layers). can be insulated to In this way, damage to the end plate 400 can be suppressed while insulating the storage element 100 and the end plate 400 . Further, since it is not necessary to arrange another insulating layer between the storage element 100 and the end plate 400, weight reduction and space saving can be achieved.

In addition, the end plate 400 has a first plate portion 410 having a plate uneven surface 410a, and a second plate portion 420 having an attachment portion 422 attached to an external member. At least one of the mounting portions 422 is arranged at the center position of the first plate portion 410 . In this way, when the second plate portion 420 is arranged at the central position of the first plate portion 410 , the force to the end plate 400 transmitted from the power storage element 100 can be received at the central position of the end plate 400 . Further, when the mounting portion 422 is arranged at the central position of the first plate portion 410, the bending moment applied to the mounting portion 422, which is the portion fixed to the external member, can be reduced. Since the force applied to the end plate 400 can be suppressed by these, the damage of the end plate 400 can be suppressed more.

The end plate 400 also has a third plate portion 430 extending from one end of the first plate portion 410 to the other end between the first plate portion 410 and the second plate portion 420 . Therefore, the force applied to the second plate portion 420 can be received from one end to the other end of the first plate portion 410 via the third plate portion 430 . As a result, unevenness of the force applied to the first plate portion 410 can be suppressed, so damage to the end plate 400 can be further suppressed.

[7 Description of Modifications]
Although power storage device 10 according to the present embodiment has been described above, the present invention is not limited to the above embodiment. In other words, the embodiments disclosed this time are illustrative in all respects and are not restrictive, and the scope of the present invention is indicated by the scope of the claims, and is within the meaning and scope equivalent to the scope of the claims. Includes all changes in

For example, in the above-described embodiment, the spacer uneven surface 310a of the end spacer 300 has a wavy shape. However, the spacer uneven surface 310a may have any shape of the spacer convex surface 311c and the spacer concave surface 312c, and the spacer inclined surface 313a inclined in any direction. may be assumed to have Further, the spacer uneven surface 310a may not have the spacer inclined surface 313a, that is, may have an uneven shape without an inclined surface.

In the above embodiment, the end spacer 300 has a surface facing the storage element 100 having a shape along the surface of the storage element 100 facing the end spacer 300 . However, the shape of the surface of the end spacer 300 facing the power storage element 100 is not limited to the above, and may have, for example, an inclined surface or an uneven surface.

Further, in the above embodiment, the protruding portion of at least one of the end spacer 300 and the end plate 400 abuts against the other, thereby forming a gap between the spacer uneven surface 310a and the plate uneven surface 410a. bottom. However, the end spacer 300 and the end plate 400 may not have such a projecting portion, and the spacer uneven surface 310a and the plate uneven surface 410a may be placed in contact with each other. Moreover, although the projecting portion is provided, the spacer uneven surface 310a and the plate uneven surface 410a may be arranged in contact with each other.

In the above embodiment, the end spacer 300 is an insulating layer extending in the Y-axis direction (second direction) and the Z-axis direction (third direction). However, at least one of the end spacers 300 and the end plates 400 should have an insulating layer extending in the second direction and the third direction. For example, an insulating layer may be arranged on or inside the end spacer 300 or the end plate 400, or the end plate 400 may be made of an insulating material.

Further, in the above embodiment, the end plate 400 is composed of three members, the first plate portion 410, the second plate portion 420, and the third plate portion 430. As shown in FIG. However, the end plate 400 may be composed of a plurality of members other than three members, or may be composed of only the first plate portion 410 .

Also, in the above embodiment, the end plate 400 has at least one of the second plate portion 420 and the mounting portion 422 arranged at the center position of the first plate portion 410 . However, both the second plate portion 420 and the mounting portion 422 may be arranged at the end portion of the first plate portion 410 .

In the above embodiment, both the positive X-axis direction side and the negative X-axis direction side of power storage device 10 have the above-described configuration. Either one of the negative axial direction sides may have a configuration different from that described above.

Moreover, the form constructed by arbitrarily combining each component provided in the above embodiment and its modification is also included in the scope of the present invention.

Moreover, the present invention can be realized not only as such a power storage device 10 but also as the end spacer 300 and the end plate 400 included in the power storage device 10 .

INDUSTRIAL APPLICABILITY The present invention can be applied to a power storage device having a power storage element such as a lithium ion secondary battery.

10 power storage device 100 power storage element 110 container 110a long side surface 300 end spacer 310 spacer main body 310a spacer uneven surface 310b spacer flat surface 311 spacer convex portion 311c spacer convex surface 312 spacer concave portion 312c spacer concave surface 313 spacer inclined portion 313a spacer inclined surface 330 spacer Protruding portion 400 End plate 410 First plate portion 410a Plate uneven surface 411 Plate concave portion 411b Plate concave surface 412 Plate convex portion 412b Plate convex surface 413 Plate inclined portion 413a Plate inclined surface 420 Second plate portion 422 Mounting portion 430 Third plate portion

Claims (7)

A power storage device comprising a power storage element,
an end plate arranged at the end of the power storage device on the first direction side;
a spacer arranged between the power storage element and the end plate;
the spacer has an uneven spacer surface facing the end plate and having an uneven shape;
the end plate has a plate uneven surface facing the spacer uneven surface and having an uneven shape along the uneven shape of the spacer uneven surface ;
at least one of the spacer and the end plate has a protrusion that protrudes toward the other and contacts the other;
A gap is formed between the spacer uneven surface and the plate uneven surface.
storage device. The gap includes a gap between surfaces orthogonal to the first direction of the spacer uneven surface and the plate uneven surface.
The power storage device according to claim 1 . 3. The power storage device according to claim 1 , wherein a surface of the spacer facing the energy storage element has a shape along a surface of the energy storage element facing the spacer. The spacer uneven surface has a spacer inclined surface inclined with respect to the first direction,
The power storage device according to any one of claims 1 to 3, wherein the plate uneven surface has a plate inclined surface along the spacer inclined surface. At least one of the spacer and the end plate has an insulating layer extending in a second direction intersecting the first direction and in a third direction intersecting the first direction and the second direction. 5. The power storage device according to any one of 4. The end plate is
a first plate portion having the uneven plate surface;
a second plate portion arranged on the first direction side of the first plate portion;
The second plate portion has an attachment portion extending in the first direction and attached to an external member,
At least one of the second plate portion and the mounting portion is arranged at a center position of the first plate portion in a third direction that intersects the first direction. storage device. The end plate further includes:
7. The electricity storage according to claim 6, further comprising a third plate portion disposed between the first plate portion and the second plate portion and extending from one end of the first plate portion to the other end in the third direction. Device.

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