JPWO2019131356A1 - Power storage device - Google Patents

Abstract

The power storage device (power storage element (10)) includes a first member (positive electrode current collector (500) (electrode connection portion (520))) and a second member (electrode) arranged on the first direction side of the first member. A body (400) (positive electrode focusing portion (410))), and the first member and the second member have a caulking joint portion (20) formed by a concavo-convex structure protruding in the first direction. The caulking joint (20) has a first convex portion (electrode body first protruding portion (411)) in which the second member protrudes in the first direction and a first concave portion (first concave portion) in which the first member is recessed in the first direction. It has a current collector first recess (523)) and a second recess recessed in the first direction from the first recess (collector second recess (524)).

Description

The present invention relates to a power storage device including two members that are caulked and joined.

Conventionally, a power storage device including two members that are caulked and joined is known. According to Patent Document 1, in a tab lead formed by joining a metal plate for solder connection to a lead body connected to an electrode in a non-aqueous electrolyte device, the lead body has a hook-shaped portion, and the metal plate has a hook. A non-aqueous electrolyte battery (power storage device) having a configuration that encloses a shaped portion and is fitted in the hook-shaped portion is disclosed.

JP-A-2015-32441

However, in a configuration in which two members are caulked and joined as in the conventional power storage device, the joint between the two members may be loosened or detached due to external vibration or impact. .. Therefore, it is desired to further improve the joint strength of the two members.

An object of the present invention is to provide a power storage device capable of improving the bonding strength of two caulked members.

The power storage device according to one aspect of the present invention is a power storage device including a power storage element, and includes a first member and a second member arranged on the first direction side of the first member. The member and the second member have a caulking joint formed by a concavo-convex structure that projects in the first direction, and the caulking joint has a first that the second member projects in the first direction. It has a convex portion, a first recess in which the first member is recessed in the first direction, and a second recess in which the first member is recessed in the first direction.

According to the power storage device of the present invention, the bonding strength of two caulked members can be improved.

FIG. 1 is a perspective view showing the appearance of the power storage element according to the embodiment. FIG. 2 is a perspective view showing components arranged inside the container of the power storage element according to the embodiment. FIG. 3 is an exploded perspective view showing each component by disassembling the power storage element according to the embodiment. FIG. 4 is a cross-sectional view showing a configuration in which the positive electrode current collector according to the embodiment is joined to the positive electrode focusing portion of the electrode body. FIG. 5 is a perspective view and a cross-sectional view showing the configuration of the caulking joint according to the embodiment. FIG. 6 is a cross-sectional view showing the configuration of the caulking joint according to the first modification of the embodiment. FIG. 7 is a cross-sectional view showing the configuration of the caulking joint according to the second modification of the embodiment.

The power storage device according to one aspect of the present invention is a power storage device including a power storage element, and includes a first member and a second member arranged on the first direction side of the first member. The member and the second member have a caulking joint formed by a concavo-convex structure that projects in the first direction, and the caulking joint has a first that the second member projects in the first direction. It has a convex portion, a first recess in which the first member is recessed in the first direction, and a second recess in which the first member is recessed in the first direction.

According to this, in the power storage device, the caulking joint formed on the first member and the second member has a first convex portion in which the second member protrudes in the first direction and a first member recessed in the first direction. However, it has a first recess and a second recess recessed in the first direction from the first recess. That is, in the caulking joint portion, when the first convex portion is formed on the second member and the first concave portion is formed on the first member for joining, the second concave portion is formed on the first concave portion. In this way, by forming the second recess in the first recess at the time of caulking, the portion at the position of the second recess spreads to the outside of the second recess, and the joint portion is compressed. As a result, the joint strength of the caulked joint portion can be improved, and the joint strength of the two caulked members (first member and second member) can be improved.

The first concave portion may be arranged such that the end portion on the first direction side thereof is arranged inward of the outer edge of the end portion on the first direction side of the first convex portion when viewed from the first direction.

According to this, in the caulking joint, the end of the first concave portion on the first direction side when viewed from the first direction is arranged inward of the outer edge of the end on the first direction side of the first convex portion. Has been done. That is, at the time of caulking, the first concave portion is formed inward of the first convex portion. As a result, the portion located at the position of the first recess can be expanded to the outside of the first recess with a relatively small force to press the joint portion, so that the joint strength of the crimped joint can be improved relatively easily.

The first member has a first part arranged on the first direction side of the second recess, and the thickness of the first part in the first direction is the thickness of the second recess in the first direction. It may be smaller than the depth.

According to this, in the caulking joint, the first member has a first part arranged on the first direction side of the second recess, and the thickness of the first part is smaller than the depth of the second recess. That is, the first portion of the first member is pressed until the thickness of the first portion of the second recess on the first direction side becomes smaller than the depth of the second recess. As a result, the first portion located at the position of the second recess spreads to the outside of the second recess and the joint portion is pressed, so that the joint strength of the caulked joint can be improved.

The first member includes a first part arranged on the first direction side of the second recess, and a second part arranged on the second direction side intersecting the first direction of the first recess. The thickness of the first part in the first direction may be smaller than the thickness of the second part in the second direction.

According to this, in the caulking joint, the first member is arranged on the first part arranged on the first direction side of the second recess and the second direction side intersecting the first direction of the first recess. It has a second part, and the thickness of the first part is smaller than the thickness of the second part. That is, the first portion of the first member is pressed until the thickness of the first portion of the second recess on the first direction side becomes smaller than the thickness of the second portion of the first recess on the second direction side. As a result, the first portion located at the position of the second recess spreads to the outside of the second recess and the joint portion is pressed, so that the joint strength of the caulked joint can be improved.

The caulking joint further has a second convex portion in which the first member protrudes in the first direction, and a third convex portion in which the first member protrudes in the first direction from the second convex portion. May be good.

According to this, the caulking joint has a second convex portion in which the first member protrudes in the first direction and a third convex portion in which the first member protrudes in the first direction from the second convex portion. That is, in the caulking joint, the first member has a two-step convex portion. As a result, a two-stage interlock is applied between the first member and the second member, and the joint strength of the caulked joint can be further improved.

The power storage element may have an electrode body, and the first member and the second member may be conductive members arranged in the path of the current flowing through the electrode body.

According to this, since the first member and the second member are conductive members arranged in the main current path, the performance of the power storage device may be deteriorated due to the decrease in the bonding strength. Therefore, the effect of improving the joint strength of the first member and the second member is great.

The present invention can be realized not only as such a power storage device, but also as two members (first member and second member) included in the power storage device.

Hereinafter, a power storage element as a power storage device according to an embodiment of the present invention (and a modification thereof) will be described with reference to the drawings. Each of the embodiments described below provides a comprehensive or specific example. Numerical values, shapes, materials, components, arrangement positions of components, connection forms, etc. shown in the following embodiments are examples, and are not intended to limit the present invention. Among the components in the following embodiments, the components not described in the independent claims indicating the top-level concept are described as arbitrary components. In each figure, the dimensions and the like are not exactly illustrated.

In the following description and drawings, the arrangement direction of the pair of electrode terminals of the power storage element, the arrangement direction of the pair of current collectors, the arrangement direction of both ends of the electrode body (the pair of active material layer non-forming portions), and the electrode body. The winding axis direction, the width direction of the legs of the current collector, or the opposite direction of the short side surface of the container is defined as the X-axis direction. Opposing direction of the long side surface of the container, short side direction of the short side surface of the container, thickness direction of the container, stacking direction of the electrode body electrode body at the caulking joint, or contact between the current collector and the electrode body at the caulking joint. The alignment direction with the board is defined as the Y-axis direction. The alignment direction of the container body and the lid of the power storage element, the longitudinal direction of the short side surface of the container, or the extension direction of the legs of the current collector is defined as the Z-axis direction. These X-axis directions, Y-axis directions, and Z-axis directions intersect each other (orthogonally in the present embodiment). In the following description, the X-axis plus direction indicates the arrow direction of the X-axis, and the X-axis minus direction indicates the direction opposite to the X-axis plus direction. The same applies to the Y-axis direction and the Z-axis direction.

(Embodiment)
[1 General description of power storage element 10]
First, with reference to FIGS. 1 to 3, a general description of the power storage element 10 according to the present embodiment will be given. The power storage element 10 is an example of a power storage device including the power storage element. That is, when the power storage device includes only one power storage element 10, the power storage device becomes the power storage element 10. Therefore, in the following, the power storage element 10 will be described as an example of the power storage device.

FIG. 1 is a perspective view showing the appearance of the power storage element 10 according to the present embodiment. FIG. 2 is a perspective view showing components arranged inside the container 100 of the power storage element 10 according to the present embodiment. Specifically, FIG. 2 is a perspective view showing a configuration in which the container body 111 is separated from the power storage element 10. That is, the figure shows a state after the positive electrode current collector 500 and the negative electrode current collector 600 are joined to the electrode body 400. FIG. 3 is an exploded perspective view showing each component by disassembling the power storage element 10 according to the present embodiment. That is, the figure shows a state before joining the positive electrode current collector 500 and the negative electrode current collector 600 to the electrode body 400. In the figure, the container body 111 is omitted.

The power storage element 10 is a secondary battery capable of charging electricity and discharging electricity, and specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The power storage element 10 is used as a power source for automobiles such as an electric vehicle (EV), a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV), a power source for electronic devices, a power source for power storage, and the like.

The power storage element 10 is not limited to the non-aqueous electrolyte secondary battery, and may be a secondary battery other than the non-aqueous electrolyte secondary battery, or may be a capacitor. The power storage element 10 may not be a secondary battery but a primary battery that can use the stored electricity without being charged by the user. The power storage element 10 may be a battery using a solid electrolyte. In the present embodiment, the rectangular parallelepiped (square) power storage element 10 is shown, but the shape of the power storage element 10 is not limited to the rectangular parallelepiped shape, and is a cylindrical shape, a long cylindrical shape, or a polygonal column shape other than the rectangular parallelepiped shape. Etc., or may be a laminated type power storage element.

As shown in FIG. 1, the power storage element 10 includes a container 100, a positive electrode terminal 200, and a negative electrode terminal 300. As shown in FIG. 2, the electrode body 400, the positive electrode current collector 500, and the negative electrode current collector 600 are housed inside the container 100.

Gaskets and the like are arranged between the lid 110 and the positive electrode terminal 200 and between the lid 110 and the positive electrode current collector 500 in order to improve insulation and airtightness, but they are omitted in the figure. Is illustrated. The same applies to the negative electrode side. An electrolytic solution (non-aqueous electrolyte) is sealed inside the container 100, but the illustration is omitted. The type of the electrolytic solution is not particularly limited as long as it does not impair the performance of the power storage element 10, and various types can be selected. In addition to the above components, spacers arranged on the sides of the positive electrode current collector 500 and the negative electrode current collector 600, a gas discharge valve for releasing the pressure in the container 100 when the pressure rises, or An insulating film or the like that wraps the electrode body 400 or the like may be arranged.

The container 100 is composed of a container main body 111 having a rectangular tubular shape and a bottom, and a lid 110 which is a plate-shaped member that closes the opening of the container main body 111. The container 100 has a structure in which the lid 110 and the container body 111 are welded or the like after the electrode body 400 or the like is housed inside, so that the inside can be sealed. The materials of the lid 110 and the container body 111 are not particularly limited, and weldable metals such as stainless steel, aluminum, and aluminum alloy can be used, but resins can also be used.

The electrode body 400 includes a positive electrode plate, a negative electrode plate, and a separator, and is a power storage element (power generation element) capable of storing electricity. The positive electrode plate is an electrode plate in which a positive electrode active material layer is formed on a positive electrode base material layer which is a long strip-shaped current collecting foil made of aluminum, an aluminum alloy, or the like. The negative electrode plate is an electrode plate in which a negative electrode active material layer is formed on a negative electrode base material layer which is a long strip-shaped current collecting foil made of copper, a copper alloy, or the like. As the current collecting foil, known materials such as nickel, iron, stainless steel, titanium, calcined carbon, conductive polymer, conductive glass, and Al—Cd alloy can also be used as appropriate. As the positive electrode active material and the negative electrode active material used for the positive electrode active material layer and the negative electrode active material layer, known materials can be appropriately used as long as they are active materials that can occlude and release lithium ions. As the separator, a microporous sheet made of resin or a non-woven fabric can be used.

In the electrode body 400, a separator is arranged between the positive electrode plate and the negative electrode plate and wound around the electrode body 400. Specifically, in the electrode body 400, the positive electrode plate and the negative electrode plate are wound by being displaced from each other in the direction of the winding shaft (virtual shaft parallel to the X-axis direction in the present embodiment) via the separator. ing. In the positive electrode plate and the negative electrode plate, a portion where the active material is not applied (the active material layer is not formed) and the base material layer is exposed (active material layer non-formed portion) is provided at the end portions in the shifted directions. Have.

That is, the electrode body 400 has laminated electrode plates (positive electrode plate and negative electrode plate). The electrode body 400 has a positive electrode focusing portion 410 in which an active material layer non-forming portion of a positive electrode plate is laminated and bundled at one end in the winding axis direction (end in the X-axis plus direction). The electrode body 400 has a negative electrode focusing portion 420 in which the active material layer non-forming portion of the negative electrode plate is laminated and bundled at the other end portion in the winding axis direction (the end portion in the minus direction of the X axis). The thickness of the active material layer non-forming portion (current collector foil) of the positive electrode plate and the negative electrode plate is about 5 μm to 20 μm, and by bundling about 30 to 40 of these, the positive electrode focusing portion 410 and the negative electrode focusing portion 420 are formed. It is formed. In the present embodiment, the cross-sectional shape of the electrode body 400 is shown as an oval shape, but it may be circular or elliptical.

The positive electrode terminal 200 is an electrode terminal electrically connected to the positive electrode plate of the electrode body 400, and the negative electrode terminal 300 is an electrode terminal electrically connected to the negative electrode plate of the electrode body 400. That is, the positive electrode terminal 200 and the negative electrode terminal 300 lead the electricity stored in the electrode body 400 to the external space of the power storage element 10, and the electricity is stored in the internal space of the power storage element 10 in order to store electricity in the electrode body 400. It is a metal electrode terminal for introducing. The positive electrode terminal 200 and the negative electrode terminal 300 are attached to a lid 110 arranged above the electrode body 400. Specifically, as shown in FIG. 3, the positive electrode terminal 200 has a positive electrode when the protruding portion 210 is inserted into the through hole 110a of the lid 110 and the opening 511 of the positive electrode current collector 500 and crimped. It is fixed to the lid 110 together with the current collector 500. The same applies to the negative electrode terminal 300.

The positive electrode current collector 500 is arranged between the positive electrode focusing portion 410 of the electrode body 400 and the side wall of the container body 111, and is electrically connected to the positive electrode terminal 200 and the positive electrode plate of the electrode body 400. It is a member provided with. The negative electrode current collector 600 is arranged between the negative electrode focusing portion 420 of the electrode body 400 and the side wall of the container body 111, and is electrically connected to the negative electrode terminal 300 and the negative electrode plate of the electrode body 400. It is a member provided with.

Specifically, the positive electrode current collector 500 and the negative electrode current collector 600 have a conductive plate shape that is arranged in a bent state along the side wall and the lid 110 from the side wall of the container body 111 to the lid 110. It is a member. The positive electrode current collector 500 and the negative electrode current collector 600 are fixedly connected (joined) to the lid 110. The positive electrode current collector 500 and the negative electrode current collector 600 are fixedly connected (bonded) to the laminated electrode plates of the electrode body 400, that is, the positive electrode focusing portion 410 and the negative electrode focusing portion 420, respectively. With this configuration, the electrode body 400 is held (supported) in a state of being suspended from the lid 110 by the positive electrode current collector 500 and the negative electrode current collector 600, and shaking due to vibration, impact, or the like is suppressed.

The material of the positive electrode current collector 500 is not limited, but is made of aluminum, an aluminum alloy, or the like, like the positive electrode base material layer of the electrode body 400. The material of the negative electrode current collector 600 is not limited, but it is formed of copper, a copper alloy, or the like, like the negative electrode base material layer of the electrode body 400.

[2 Explanation of the configuration around the caulking joint 20]
As shown in FIG. 2, the positive electrode current collector 500 is joined to the positive electrode focusing portion 410 of the electrode body 400 at a plurality of caulking joint portions 20. The negative electrode current collector 600 is joined to the negative electrode focusing portion 420 of the electrode body 400 at a plurality of caulking joint portions 30. The schematic configuration around the caulking joints 20 and 30 will be described below with reference to FIG. Since the area around the caulking joint 20 on the positive electrode side and the area around the caulking joint 30 on the negative electrode side have the same configuration, the configuration around the caulking joint 20 on the positive electrode side will be described below. The description of the configuration around the caulking joint 30 will be omitted.

FIG. 4 is a cross-sectional view showing a configuration in which the positive electrode current collector 500 according to the present embodiment is joined to the positive electrode focusing portion 410 of the electrode body 400. Specifically, the figure shows a configuration in which the positive electrode current collector 500 and the positive electrode focusing portion 410 shown in FIG. 2 are cut in a YZ plane passing through the caulking joint portion 20.

As shown in FIGS. 3 and 4, the positive electrode current collector 500 includes a terminal connection portion 510 and two electrode connection portions extending from both ends of the terminal connection portion 510 in the Y-axis direction in the negative direction of the Z-axis. It has 520 and.

The terminal connection portion 510 is a base portion of the positive electrode current collector 500 connected (bonded) to the positive electrode terminal 200. That is, the terminal connection portion 510 is a flat plate-shaped portion arranged on the positive electrode terminal 200 side (upper side, Z-axis plus direction) of the positive electrode current collector 500, and is electrically and mechanically connected to the positive electrode terminal 200. ..

The electrode connecting portion 520 is a leg portion of the positive electrode current collector 500 connected (bonded) to the electrode body 400. That is, the electrode connecting portion 520 is a portion arranged on the electrode body 400 side (lower side, Z-axis minus direction side) of the positive electrode current collector 500, and is electrically and mechanically connected to the electrode body 400. Specifically, the electrode connecting portion 520 is a long and flat portion extending in the Z-axis direction, and has two opposed flat focusing portions in the positive electrode focusing portion 410 of the electrode body 400. The electrode connection portions 520 are joined to each other.

As shown in FIG. 4, a backing plate 700 is arranged inside the positive electrode focusing portion 410, and the electrode connecting portion 520, the positive electrode focusing portion 410, and the backing plate 700 are mechanically joined to four (2). A caulking joint 20 (two at each electrode connection 520) is formed. That is, the electrode connecting portion 520 and the positive electrode focusing portion 410 include a caulking joint portion 20 in which one of them is fitted to each other in a concavo-convex structure in which one of them projects toward the other. Specifically, the caulking joint portion 20 is formed with an uneven structure in which the electrode connecting portion 520 and the positive electrode focusing portion 410 project in the Y-axis positive direction or the Y-axis negative direction (hereinafter, also referred to as the first direction). The electrode connecting portion 520 and the positive electrode focusing portion 410 are fitted and joined to each other. The caulking joint portion 20 can be formed by caulking and plastically deforming the electrode connecting portion 520, the positive electrode focusing portion 410, and the backing plate 700 (specifically, by performing clinch caulking jointing).

The electrode connecting portion 520 (positive electrode current collector 500) is an example of the first member, and the positive electrode focusing portion 410 (electrode body 400) is an example of the second member arranged on the first direction side of the first member. is there. The electrode connecting portion 520 (positive electrode current collector 500) and the positive electrode focusing portion 410 (electrode body 400) are examples of conductive members arranged in the path of the current flowing through the electrode body 400. The current flowing through the electrode body 400 is the charging current of the power storage element 10 or the discharge current (main current) of the power storage element 10. The current path is a current path between the electrode body 400 and the positive electrode terminal 200 and the negative electrode terminal 300, or a current path from the positive electrode terminal 200 and the negative electrode terminal 300 to the outside of the power storage element 10.

The caulking joint 20 is a cylindrically protruding portion, and the two caulking joints 20 are arranged so as to project toward each other at positions facing each other. That is, the first member and the second member have two pairs (two pairs) of a pair of caulking joints 20 at positions facing each other in the Y-axis direction. A detailed description of the configuration of the caulking joint 20 will be described later.

The backing plate 700 is a cover that protects the positive electrode focusing portion 410, which is arranged at a position sandwiching the positive electrode focusing portion 410 with the electrode connecting portion 520. Specifically, the backing plate 700 is a rectangular and flat plate-shaped member extending in the Z-axis direction along the positive electrode focusing portion 410, and is formed so as to have a uniform thickness in the state before joining. There is. The material of the backing plate 700 is not particularly limited, but is a metal member made of aluminum, an aluminum alloy, or the like, like the positive electrode base material layer of the electrode body 400. A backing plate is similarly arranged on the negative electrode side, and the material of the backing plate on the negative electrode side is not particularly limited, but is formed of copper or a copper alloy or the like like the negative electrode base material layer of the electrode body 400. It is a metal member.

[3 Explanation of the configuration of the caulking joint 20]
Next, the configuration of the caulking joint 20 will be described in more detail. FIG. 5 is a perspective view and a cross-sectional view showing the configuration of the caulking joint portion 20 according to the present embodiment. Specifically, FIG. 5A is a perspective view of the caulking joint 20 on the Y-axis minus direction side shown in FIG. 4 as viewed from the backing plate 700 side (protruding side). FIG. 5B is a cross-sectional view showing a configuration when the caulking joint portion 20 shown in FIG. 5A is cut along a YZ plane including a Vb-Vb line. The caulking joint 20 on the positive side of the Y-axis shown in FIG. 4 has the opposite direction to the caulking joint 20 on the negative side of the Y-axis in the Y-axis direction, but the description is omitted because the configuration is the same. To do.

As shown in FIG. 5, the caulking joint portion 20 is a joint portion having a circular shape when viewed from above, which protrudes in the positive direction of the Y axis. In the figure, the top view is a view from the Y-axis plus direction. The top view circular shape means that it has a circular shape when viewed from the Y-axis plus direction. Specifically, in the caulking joint portion 20, the electrode connecting portion 520 of the positive electrode current collector 500 projects toward the positive electrode focusing portion 410 of the electrode body 400, and the bottomed substantially cylindrical portion of the electrode connecting portion 520 is formed. The positive electrode focusing portion 410 has a concave-convex structure that protrudes toward a substantially cylindrical portion with a bottom. In the caulking joint portion 20, the positive electrode focusing portion 410 protrudes toward the backing plate 700, and the bottomed substantially cylindrical portion of the positive electrode focusing portion 410 protrudes toward the bottomed substantially cylindrical portion of the backing plate 700. It can be said that it has an uneven structure.

In such a configuration, the electrode connecting portion 520, the positive electrode focusing portion 410, and the backing plate 700 have a first protruding portion (current collector first protruding portion 521, electrode) projecting in the first direction at the caulking joint portion 20. It has a body first protruding portion 411 and a plate first protruding portion 701). The first direction is the protruding direction of the first protruding portion, that is, the direction from the electrode connecting portion 520 toward the backing plate 700, and is the Y-axis plus direction in FIG. The first protruding portion has a second protruding portion (current collector second protruding portion 522 and electrode body second protruding portion 412) protruding in the second direction intersecting the first direction. In the present embodiment, the second direction is a direction orthogonal to the first direction, and is all directions in the XZ plane (both sides in the Z-axis direction in FIG. 5).

Specifically, the electrode connecting portion 520 has a current collector first protruding portion 521 that protrudes in the first direction (Y-axis plus direction) toward the positive electrode focusing portion 410. The current collector first protruding portion 521 is a bottomed substantially cylindrical convex portion in which the surface of the electrode connecting portion 520 on the positive electrode focusing portion 410 side protrudes toward the positive electrode focusing portion 410 side. In other words, the current collector first protruding portion 521 has a shape in which the surface of the electrode connecting portion 520 opposite to the positive electrode focusing portion 410 is recessed toward the positive electrode focusing portion 410 side. That is, the current collector first protrusion 521 is formed with a current collector first recess 523 in which the electrode connecting portion 520 is recessed in the first direction. The current collector first recess 523 is a concave portion having a circular shape when viewed from above, which is formed on the back side of the current collector first protrusion 521. The current collector first recess 523 is an example of a first recess in which the first member is recessed in the first direction.

The current collector first protrusion 521 is formed with a current collector second recess 524 recessed in the first direction from the current collector first recess 523. The current collector second recess 524 is a concave portion having a circular shape when viewed from above, in which the central portion of the bottom portion located on the first direction side of the current collector first protrusion 521 is recessed in the first direction. As a result, in the current collector first protruding portion 521, the current collector first part 525, which is a thin portion, is formed on the first direction side of the current collector second recess 524. The current collector first part 525 is a thin-walled portion having a circular shape (disk shape) formed in the central portion of the bottom portion of the current collector first recess 523. The current collector second recess 524 is an example of a second recess recessed in the first direction from the first recess. The current collector first part 525 is an example of the first part arranged on the first direction side of the second recess.

The thickness of the current collector first part 525 is smaller than the depth of the current collector second recess 524. That is, the thickness D1 of the current collector first part 525 in the first direction is smaller than the depth D2 of the current collector second recess 524 in the first direction. The minimum value of the thickness D1 of the current collector first part 525 may be smaller than the maximum value of the depth D2 of the current collector second recess 524, but the maximum value of the thickness D1 of the current collector first part 525 is , It is preferable that the depth D2 of the second recess 524 of the current collector is smaller than the minimum value.

The thickness of the current collector first part 525 is smaller than the thickness of the current collector second part 526 arranged on the second direction side intersecting the first direction of the current collector first recess 523. The current collector second portion 526 is a substantially cylindrical portion forming a side wall of the current collector first protrusion 521. That is, the thickness D1 of the current collector first part 525 in the first direction is smaller than the thickness D3 of the current collector second part 526 in the second direction. The minimum value of the thickness D1 of the current collector first part 525 may be smaller than the maximum value of the thickness D3 of the current collector second part 526, but the maximum value of the thickness D1 of the current collector first part 525 is It is preferably smaller than the minimum value of the thickness D3 of the second part 526 of the current collector. The second part 526 of the current collector is an example of the second part arranged on the second direction side intersecting the first direction of the first recess.

The current collector first protruding portion 521 has a current collector second protruding portion 522 that protrudes in the second direction. The current collector second protrusion 522 is an annular top view projecting from the end of the current collector first protrusion 521 on the first direction side toward the electrode body first protrusion 411 over the entire circumference. It is a part.

The positive electrode focusing portion 410 is arranged on the first direction side (Y-axis plus direction side) of the current collector first protruding portion 521 of the electrode connecting portion 520, and the electrode body first projecting toward the backing plate 700 in the first direction. It has one protruding portion 411. The electrode body first protruding portion 411 is a bottomed substantially cylindrical convex portion in which the surface of the positive electrode focusing portion 410 on the backing plate 700 side protrudes toward the backing plate 700. In other words, the electrode body first protruding portion 411 has a shape in which the surface of the positive electrode focusing portion 410 on the electrode connecting portion 520 side is recessed toward the backing plate 700 side. That is, the electrode body first protrusion 411 is formed with the electrode body first recess 413 in which the positive electrode focusing portion 410 is recessed in the first direction. The electrode body first recess 413 is a top view circular recess formed on the back side of the electrode body first protrusion 411.

The electrode body first protruding portion 411 has an electrode body first part 414 which is a disk-shaped bottom portion located on the first direction side, and an electrode body second part 415 which is a substantially cylindrical side wall. The electrode body first part 414 is a portion arranged on the first direction side of the current collector first part 525, and the electrode body second part 415 is the entire circumference along the outer circumference of the current collector second part 526. It is a part placed in. That is, when viewed from the first direction, the end portion of the current collector second portion 526 on the first direction side is arranged inward of the end portion of the electrode body second portion 415 on the first direction side. In other words, the end of the current collector first recess 523 on the first direction side when viewed from the first direction is arranged inside the outer edge of the end on the first direction side of the electrode body first protrusion 411. Has been done.

The electrode body first protrusion 411 has an electrode body second protrusion 412 that protrudes in the first direction and the second direction. The electrode body second protrusion 412 extends from the end of the electrode body first protrusion 411 on the first direction side toward the plate first protrusion 701 and the plate second protrusion 702 described later over the entire circumference. It is an annular part of the top view that protrudes. The electrode body first protruding portion 411 is an example of a first convex portion in which the second member protrudes in the first direction.

The backing plate 700 is arranged on the first direction side (Y-axis plus direction side) of the electrode body first protrusion 411 of the positive electrode focusing portion 410, and is projected in the first direction toward the direction away from the positive electrode focusing portion 410. It has a plate first protrusion 701. The first protruding portion 701 of the plate is a bottomed substantially cylindrical convex portion whose surface of the backing plate 700 opposite to the positive electrode focusing portion 410 protrudes to the opposite side of the positive electrode focusing portion 410. In other words, the first protruding portion 701 of the plate has a shape in which the surface of the backing plate 700 on the positive electrode focusing portion 410 side is recessed toward the side opposite to the positive electrode focusing portion 410. That is, the plate first protrusion 701 is formed with the plate first recess 703 in which the backing plate 700 is recessed in the first direction. The plate first recess 703 is a top-view circular recess formed on the back side of the plate first protrusion 701.

The plate first protruding portion 701 has a plate-shaped bottom portion 704, which is a disk-shaped bottom portion located on the first direction side, and a plate second portion 705, which is a substantially cylindrical side wall. The first part 704 of the plate is a portion arranged on the first direction side of the first part 414 of the electrode body, and the second part 705 of the plate is arranged all around along the outer circumference of the second part 415 of the electrode body. It is the part to be done. That is, when viewed from the first direction, the end portion on the first direction side of the second portion 415 of the electrode body is arranged inward of the end portion on the first direction side of the second portion 705 of the plate. In other words, in the electrode body first recess 413, the end portion on the first direction side when viewed from the first direction is arranged inward of the outer edge of the end portion on the first direction side of the plate first protrusion 701. ing.

The plate first protrusion 701 has a plate second protrusion 702 that protrudes in the first direction and is annular in the top view at the end on the first direction side.

Of the current collector first protrusion 521, the electrode body first protrusion 411, the plate first protrusion 701, the current collector second protrusion 522, the electrode body second protrusion 412, and the plate second protrusion 702. The protruding direction is not limited to the above direction. The direction may be inclined from the above direction, and the protruding shape is not limited to the above. The second protruding portion 522 of the current collector may also protrude in the first direction. The second protruding portion 412 of the electrode body does not have to protrude in the first direction. The second protrusion 702 of the plate does not have to protrude in the first direction.

The second protruding portion 702 of the plate may project in the second direction from the end on the first direction side of the first protruding portion 701 of the plate. In order to make it easy to remove from the plate, it is preferable that the second protruding portion 702 of the plate does not protrude in the second direction. Similarly, in order to make the caulking joint 20 easier to remove from the die, the width of the plate first protrusion 701 and the plate second protrusion 702 in the second direction (width in the Z-axis direction in FIG. 5) is set. It is preferable that the size becomes smaller toward the tip (the end on the first direction side). Similarly, in order to make it easier to remove the caulking joint 20 from the punch, the width of the current collector first recess 523 and the current collector second recess 524 in the second direction (width in the Z-axis direction in FIG. 5) is set at the tip. It is preferable that the size becomes smaller toward (the end on the first direction side).

[4 Explanation of effect]
As described above, according to the power storage element 10 as the power storage device according to the embodiment of the present invention, the electrode connection portion 520 (first member) of the positive electrode current collector 500 and the positive electrode focusing portion 410 (the first member) of the electrode body 400. In the caulking joint portion 20 formed in the two members), the electrode body first protruding portion 411 (first convex portion) in which the positive electrode focusing portion 410 protrudes in the first direction and the electrode connecting portion 520 are recessed in the first direction. It has a current collector first recess 523 (first recess) and a current collector second recess 524 (second recess) recessed in the first direction from the current collector first recess 523. That is, in the caulking joint portion 20, when the electrode body first protrusion 411 is formed in the positive electrode focusing portion 410 and the current collector first recess 523 is formed in the electrode connection portion 520 to perform the joining, the current collector first is formed. A second recess 524 of the current collector is formed in the recess 523. In this way, by forming the current collector second recess 524 in the current collector first recess 523 at the time of caulking, the portion at the position of the current collector second recess 524 becomes the current collector second. It spreads to the outside of the recess 524 and the joint is compressed. As a result, the bonding strength of the caulked joint portion 20 can be improved, and the bonding strength of the two caulked members (positive electrode current collector 500 and electrode body 400) can be improved.

In the caulking joint 20, the end of the current collector first recess 523 on the first direction side when viewed from the first direction is the inner edge of the outer edge of the first direction end of the electrode body first protrusion 411. It is located in the direction. That is, at the time of caulking, the current collector first recess 523 is formed inward of the electrode body first protrusion 411. As a result, the portion located at the current collector first recess 523 can be expanded to the outside of the current collector first recess 523 with a relatively small force to press the joint portion, so that the joint can be caulked relatively easily. The joint strength of the portion 20 can be improved.

In the caulking joint portion 20, the electrode connecting portion 520 has a current collector first part 525 (first part) arranged on the first direction side of the current collector second recess 524, and is a current collector first part. The thickness of 525 is smaller than the depth of the second recess 524 of the current collector. That is, the current collector first until the thickness of the current collector first part 525 on the first direction side of the current collector second recess 524 in the electrode connection portion 520 becomes smaller than the depth of the current collector second recess 524. Squeeze part 525. As a result, the current collector first part 525, which was located at the position of the current collector second recess 524, spreads to the outside of the current collector second recess 524, and the joint portion is compressed, so that the caulking joint portion 20 is joined. The strength can be improved.

In the caulking joint portion 20, the electrode connecting portion 520 has a current collector second portion 526 (second portion) arranged on the second direction side intersecting the first direction of the current collector first recess 523. The thickness of the current collector first part 525 is smaller than the thickness of the current collector second part 526. That is, the thickness of the current collector first part 525 on the first direction side of the current collector second recess 524 in the electrode connection portion 520 is the thickness of the current collector second part 525 on the second direction side of the current collector first recess 523. The current collector first part 525 is pressed until it becomes smaller than the thickness of 526. As a result, the current collector first part 525, which was located at the position of the current collector second recess 524, spreads to the outside of the current collector second recess 524, and the joint portion is compressed, so that the caulking joint portion 20 is joined. The strength can be improved.

Since the electrode connecting portion 520 and the positive electrode focusing portion 410 are conductive members arranged in the main current path, the performance of the power storage element 10 may deteriorate due to the decrease in bonding strength. Therefore, the effect of improving the joint strength of the electrode connecting portion 520 and the positive electrode focusing portion 410 is great.

Generally, when two conductive members are caulked and bonded, the contact area tends to be smaller than that of bonding such as ultrasonic welding, but the electrode connecting portion 520 and the positive electrode focusing portion 410 have a main current. Since it is a flowing part, the current resistance increases as the contact area decreases. Therefore, in the caulking joint portion 20, by forming the current collector second recess 524 and expanding the joint portion to the outside, the contact area can be increased and the energization resistance can be suppressed from increasing.

Two-stage (double) caulking joints can also form two-stage recesses (current collector first recess 523 and current collector second recess 524). In this case, the positive electrode focusing portion 410 and the backing plate are formed. Since the two-step convex portion is formed on the 700, the protruding height of the caulking joint portion becomes high. Therefore, the caulking joint portion 20 in the present embodiment can keep the protruding height low as compared with the case where the two-stage caulking joint is performed, and space can be saved.

Since the negative electrode current collector 600 side has the same configuration as the positive electrode current collector 500 side, the same effect can be obtained.

[5 Description of a modified example of the embodiment]
(Modification example 1)
Next, a modification 1 of the above embodiment will be described. FIG. 6 is a cross-sectional view showing the configuration of the caulking joint portion 20a according to the first modification of the present embodiment. The figure corresponds to (b) of FIG.

As shown in FIG. 6, the caulking joint portion 20a in the present modification has a current collector first protruding portion 521a instead of the current collector first protruding portion 521 of the caulking joint portion 20 in the above embodiment. ing. The current collector first protruding portion 521a includes the current collector first recess 523, the current collector second recess 524, the current collector first part 525, and the current collector of the current collector first protruding portion 521 in the above embodiment. Instead of the second body part 526, it has a current collector first recess 523a, a current collector second recess 524a, a current collector first part 525a, and a current collector second part 526a. Other configurations of this modification are the same as those of the above embodiment, and detailed description thereof will be omitted.

Specifically, the current collector first protruding portion 521a is formed with a current collector second recess 524a having a depth deeper than that of the current collector second recess 524 in the above embodiment. That is, the current collector second recess 524a is formed so as to be recessed in the first direction from the Y-axis minus direction side with respect to the center position of the current collector first recess 523a in the Y-axis direction. As a result, on the first direction side of the second recess 524a of the current collector, the current collector first part 525a having a circular shape (disk shape) having a diameter larger than that of the current collector first part 525 in the above embodiment. Is placed. A substantially cylindrical current collector second portion 526a is arranged on the second direction side of the current collector second recess 524a. Similar to the above embodiment, the thickness D1 of the current collector first part 525a in the first direction is smaller than the depth D2 of the current collector second recess 524a in the first direction, and the current collector second part 526a It is smaller than the thickness D3 in the second direction of.

As described above, according to the caulking joint portion 20a according to the present modification, the same effect as that of the above-described embodiment is obtained. In particular, in this modification, the joint strength of the caulking joint portion 20 can be improved by forming the current collector second recess 524a having a deep depth.

(Modification 2)
Next, a modification 2 of the above embodiment will be described. FIG. 7 is a cross-sectional view showing the configuration of the caulking joint portion 20b according to the second modification of the present embodiment. The figure corresponds to (b) of FIG.

As shown in FIG. 7, the caulking joint portion 20b in this modified example is a current collector instead of the current collector first protruding portion 521 and the electrode body first protruding portion 411 of the caulking joint portion 20 in the above embodiment. It has a first protruding portion 521b and a first protruding portion 411b of the electrode body. The current collector first protruding portion 521b is a convex portion in which the electrode connecting portion 520 protrudes in the first direction, and has a current collector third protruding portion 527 protruding in the first direction. The electrode body first protruding portion 411b is a convex portion in which the positive electrode focusing portion 410 protrudes in the first direction, and has an electrode body third protruding portion 416 protruding in the first direction. Other configurations of this modification are the same as those of the above embodiment, and detailed description thereof will be omitted.

As described above, the current collector first protruding portion 521b and the electrode body first protruding portion 411b each have a two-stage convex portion. The first-stage convex portion of the current collector first protruding portion 521b is an example of a second convex portion in which the first member protrudes in the first direction, and the second-stage convex portion (current collector third protruding portion). 527) is an example of a third convex portion protruding in the first direction from the second convex portion.

As described above, according to the caulking joint portion 20b according to the present modification, the same effect as that of the above-described embodiment is obtained. In particular, in this modification, in the caulking joint portion 20b, the current collector first protruding portion 521b has a two-stage convex portion. As a result, a two-stage interlock is applied between the electrode connecting portion 520 and the positive electrode focusing portion 410, and the bonding strength of the caulking joint portion 20b can be improved. Since the first protruding portion 411b of the electrode body also has a two-step convex portion, a two-step interlock is applied between the positive electrode focusing portion 410 and the backing plate 700, further improving the joint strength of the caulking joint portion 20b. it can.

In this modification, at least one of the current collector first protruding portion 521b and the electrode body first protruding portion 411b may have a two-stage convex portion. That is, the electrode body first protruding portion 411b may not have the two-step convex portion, and the current collector first protruding portion 521b may not have the two-step convex portion.

(Other variants)
Although the power storage element as the power storage device according to the embodiment of the present invention and the modified example thereof has been described above, the present invention is not limited to the embodiment and the modified example thereof. That is, it should be considered that the embodiments disclosed this time and examples thereof are examples in all respects and are not restrictive. The scope of the present invention is shown not by the above description but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

In the caulking joint 20 of the above-described embodiment and its modification, an interatomic bond may be formed between the current collector first part 525 and 525a and the electrode body first part 414. That is, at the time of current collector caulking, the oxide film existing on the surface of the current collector first part 525 is broken to expose a new metal surface, and an interatomic bond is formed with the electrode body first part 414. To. Thereby, the joint strength of the caulking joint portion 20 can be further improved.

In the above-described embodiment and its modification, it is assumed that the pair of caulking joints are arranged at positions facing each other. However, the caulking joints do not have to be located at opposite positions. The number of caulking joints is not particularly limited, and any number of caulking joints may be formed in the electrode connecting portion 520. The number of electrode connection portions 520 is not limited, and the positive electrode current collector 500 may have only one electrode connection portion 520, or may have three or more electrode connection portions 520. You may decide. When the electrode connecting portion 520 is made into one, the dies and punches can be easily arranged on both sides of the electrode connecting portion 520, so that the caulking joint can be easily formed.

In the above embodiment and the modified example thereof, it is assumed that the positive electrode current collector 500 has caulking joints formed on both of the two electrode connection portions 520, but only on one of the electrode connection portions 520. A configuration in which a caulking joint is formed may be used. In the power storage element, it was decided that a junction was formed on both the positive electrode current collector 500 and the negative electrode current collector 600, but the junction was formed only on either the positive electrode current collector 500 or the negative electrode current collector 600. May be formed.

In the above embodiment and the modified example thereof, the caulking joint portion is determined to protrude in the positive direction or the negative side of the Y axis (in the positive direction of the Y axis in FIGS. 5 to 7). That is, the caulking joint portion is a joint portion having a concavo-convex structure in which the positive electrode current collector 500 projects toward the electrode body 400 and the backing plate 700. However, the caulking joint portion may be a joint portion having an uneven structure in which the backing plate 700 and the electrode body 400 project toward the positive electrode current collector 500. This configuration is preferable when the backing plate 700 is thicker than the positive electrode current collector 500. The caulking joint portion may have a shape in which the protruding height is lowered by being crushed in the height direction (Y-axis direction).

In the above-described embodiment and its modified example, the caulking joint portion has an outer shape having a circular shape when viewed from above. However, the outer shape of the caulked joint may be oval, elliptical, polygonal, or the like when viewed from above. Similarly, the first concave portion formed in the caulked joint may have an oval shape, an elliptical shape, a polygonal shape, or the like when viewed from above.

In the above-described embodiment and its modified example, in the caulking joint portion, a second concave portion having a circular shape when viewed from above is formed in the central portion of the bottom portion of the first concave portion. However, the second recess may be formed at the end of the bottom of the first recess, and the shape is not particularly limited, and may be oval, elliptical, polygonal, or the like when viewed from above. May be good.

In the above-described embodiment and its modification, the caulking joint portion is determined to have one second recess formed in the first recess. However, in the caulking joint, a plurality of second recesses may be formed in the first recess, or a third recess is further formed in the second recess, and three or more recesses are formed. It may have been.

In the above-described embodiment and its modification, the thickness of the first part of the caulked joint is smaller than the depth of the second recess and smaller than the thickness of the second part. However, the thickness of the first part may be larger than the depth of the second recess, or may be larger than the thickness of the second part.

In the above-described embodiment and its modification, the first recess and the second recess of the caulking joint may be formed by one caulking operation or may be formed by dividing into a plurality of caulking operations.

In the above embodiment and its modified example, the electrode body 400 is a so-called vertically wound winding type electrode body in which the winding shaft is parallel to the lid body 110. However, the electrode body 400 may be a so-called horizontal winding type electrode body in which the winding axis is perpendicular to the lid body 110. The shape of the electrode body 400 is not limited to the winding type, and may be a stack type in which flat plate-shaped electrode plates are laminated, a electrode plate and / or a separator folded in a bellows shape.

In the above-described embodiment and its modification, the positive electrode current collector 500, the electrode body 400, and the backing plate 700 are joined, but other members may also be joined together. Alternatively, the backing plate 700 may not be provided, and the positive electrode current collector 500 and the electrode body 400 may be joined to form a caulking joint.

In the above-described embodiment and its modification, the positive electrode current collector 500 and the electrode body 400 are joined only at the caulking joint, but in addition to the joining at the caulking joint, joining by another joining method is used. May be done. Other bonding methods include ultrasonic welding, resistance welding, arc welding, and welding by irradiating a laser or electron beam. In this way, by performing joining by another joining method in addition to the caulking joint portion, it is possible to improve the joining strength and reduce the contact resistance.

In the above embodiment and its modified example, it is assumed that one caulking joint is formed independently. However, a plurality of caulking joints may be formed in succession. Adjacent portions of the two caulking joints may be integrated into a shape in which the two caulking joints are connected (twin point), or three or more caulking joints may be connected and integrated. .. With such a configuration, it is possible to improve the joint strength and reduce the contact resistance.

In the above-described embodiment and its modification, clinch caulking bonding is exemplified as an example of plastically deforming the positive electrode current collector 500 and the electrode body 400 when the positive electrode current collector 500 and the electrode body 400 are bonded. However, the present invention is not limited to this, and a caulking joint different from the clinch caulking joint may be used.

In the above embodiment and its modification, the first member is a current collector (electrode connecting portion 520 of the positive electrode current collector 500), and the second member is the electrode body 400 (positive electrode focusing portion 410). And said. However, the first member and the second member may be two members arranged in the path of the current flowing through the electrode body 400 and joined to each other, and are not limited to the current collector and the electrode body 400. When a conductive member such as a lead is arranged between the electrode body 400 and the current collector, the first member and the second member may be the electrode body 400 and the conductive member, or the current collector. And the conductive member. When the electrode terminal (positive electrode terminal 200 or negative electrode terminal 300) is composed of two members, the first member and the second member may be the two members constituting the electrode terminal. When the current collector (positive electrode current collector 500 or negative electrode current collector 600) is composed of two members, the first member and the second member may be the two members constituting the current collector. Good. The first member and the second member may be an electrode terminal and a current collector. When the container 100 is dropped to the potential of the positive electrode or the negative electrode, the first member and the second member may be an electrode terminal and a container 100, or may be a current collector and a container 100.

In the above embodiment and its modification, the power storage device includes only one power storage element (that is, the power storage device is a power storage element), and the first member and the second member are two members of the power storage element. It was decided to be. However, the power storage device is a module including a plurality of power storage elements or a pack including a plurality of the modules, and the first member and the second member may be two members included in the module or the pack. Good. When the first member and the second member are provided in the module, the first member and the second member are a bus bar between the electrode terminal of the power storage element and the power storage element, or a bus bar connected to the electrode terminal of the power storage element. And may be an external terminal of the module, or may be the two members when these bus bars are composed of two members. When the first member and the second member are provided in the pack, the first member and the second member are of the bus bar and the pack connected to the external terminal of the module and the bus bar between the modules and the external terminal of the module. It may be an external terminal, or it may be the two members when these bus bars are composed of two members. When the power storage device is provided with a relay or a fuse, the first member and the second member may be a bus bar and a relay, or a bus bar and a fuse. Even in these cases, the configurations of the first member and the second member and their effects are the same as those of the above-described embodiment and its modifications.

Further, the first member and the second member may be two metal members in the module or pack that are not arranged in the path of the current flowing through the electrode body 400. As the first member and the second member, an end plate arranged at both ends of the plurality of power storage elements to sandwich the plurality of power storage elements, a restraint bar connected to the end plate and restraining the plurality of power storage elements, and the like can be considered. Be done. Alternatively, as the first member and the second member, an exterior body and a lid of an exterior body accommodating a plurality of power storage elements can be considered. The first member and the second member may be two adjacent exterior bodies (two adjacent module cases, two adjacent pack cases, etc.).

The first member and the second member may be two plates other than the metal member such as reinforced plastic in the module or the pack instead of the two metal members. As the first member and the second member, the above-mentioned end plate and restraint bar, the outer body of the outer body, the lid, and the like can be considered. The first member and the second member may be two adjacent exterior bodies (two adjacent module cases, two adjacent pack cases, etc.).

The scope of the present invention also includes a form constructed by arbitrarily combining the components included in the above-described embodiment and its modifications.

The present invention can be realized not only as such a power storage device, but also as two members (first member and second member) included in the power storage device.

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

10 Power storage elements 20, 20a, 20b, 30 Caulking joint 400 Electrode body 410 Positive electrode focusing part 411, 411b Electrode body first protrusion 412 Electrode body second protrusion 413 Electrode body first recess 414 Electrode body first part 415 Electrode Body second part 416 Electrode body third protrusion 500 Positive electrode current collector 520 Electrode connection part 521, 521a, 521b Current collector first protrusion 522 Current collector second protrusion 523, 523a Current collector first recess 524 , 524a Current collector second recess 525, 525a Current collector first part 526, 526a Current collector second part 527 Current collector third protrusion

Claims (6)

A power storage device equipped with a power storage element
A first member and a second member arranged on the first direction side of the first member are provided.
The first member and the second member have a caulking joint formed with a concavo-convex structure protruding in the first direction.
The caulking joint is
The first convex portion from which the second member protrudes in the first direction,
A first recess in which the first member is recessed in the first direction,
A power storage device having a second recess recessed from the first recess in the first direction. Claim 1 in which the end portion of the first concave portion on the first direction side is arranged inside the outer edge of the end portion of the first convex portion on the first direction side when viewed from the first direction. The power storage device described in. The first member has a first portion arranged on the first direction side of the second recess.
The power storage device according to claim 1 or 2, wherein the thickness of the first part in the first direction is smaller than the depth of the second recess in the first direction. The first member includes a first part arranged on the first direction side of the second recess, and a second part arranged on the second direction side intersecting the first direction of the first recess. Have,
The power storage device according to any one of claims 1 to 3, wherein the thickness of the first part in the first direction is smaller than the thickness of the second part in the second direction. The caulking joint further
A second convex portion from which the first member protrudes in the first direction,
The power storage device according to any one of claims 1 to 4, further comprising a third convex portion protruding from the second convex portion in the first direction. The power storage element has an electrode body and has an electrode body.
The power storage device according to any one of claims 1 to 5, wherein the first member and the second member are conductive members arranged in a path of an electric current flowing through the electrode body.

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