JP2019067762A - Manufacturing method of power storage element, power storage element, and power storage device - Google Patents

Abstract

To provide a manufacturing method of a power storage element capable of suppressing damage to a joint portion of two conductive members.SOLUTION: A manufacturing method of a power storage element 10 including a first conductive member and a second conductive member disposed in a path of current flowing through an electrode body 400 and joined to each other includes a first forming step of forming a recess or a through hole in at least one of the first conductive member and the second conductive member and a second forming step of forming a caulking joint portion 20 having a concavo-convex structure in which any one of the first conductive member and the second conductive member protrudes toward the other at a position where the recess or the through hole is formed.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a method of manufacturing a storage element including two conductive members joined to each other, a storage element, a storage device, and the like.

  Conventionally, a storage element is known which comprises two conductive members joined together. For example, Patent Document 1 discloses a storage element having a configuration in which an electrode body and a current collector are joined.

JP, 2016-189323, A

  In the above conventional storage element, two conductive members (electrode body and current collector) are crimped and joined. Here, when two conductive members are crimped and joined, it is preferable to apply oil to the die or punch to perform caulking in order to easily peel the conductive member from the joining tool (die, punch) after the caulking. It is known. However, the inventor of the present application may find that when the oil above the specified amount is accumulated between the die and the punch, the thickness of the crimped joint becomes thin due to the crimped joint being compressed by the thickness of the oil. I found out. When the thickness of the caulking joint becomes thinner, a thin portion of the caulking joint may be broken, or if the caulking joint is a main current path, a large current flows in the thin portion of the caulking joint. There is a possibility that the joint portion may be damaged, such as being melted and broken.

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide a method of manufacturing an electric storage device, an electric storage device, an electric storage device and the like which can suppress damage to a joint portion of two conductive members. I assume.

  In order to achieve the above object, a method of manufacturing a storage element according to an aspect of the present invention includes a storage element including a first conductive member and a second conductive member disposed in a path of current flowing through an electrode body and joined to each other. A manufacturing method, comprising: forming a recess or a through hole in at least one of the first conductive member and the second conductive member; any one of the first conductive member and the second conductive member And a second forming step of forming a crimped joint of a concavo-convex structure in which one protrudes toward the other at a position where the recess or the through hole is formed.

  According to this, in the method of manufacturing the storage element, the recess or the through hole is formed in at least one of the first conductive member and the second conductive member disposed in the path of the current flowing through the electrode body, and the first conductive member And forming a crimped joint at a position where the recess or through hole of the second conductive member is formed. That is, after forming a recess or a through hole in at least one of the first conductive member and the second conductive member, caulking bonding is performed. Thereby, even when oil is accumulated between the die and the punch at the time of caulking and bonding, the oil can be released to the recess or the through hole. For this reason, it can suppress that the oil between a die | dye and punch presses a crimp joint, and it can suppress that the thickness of a crimp joint becomes thin. If the thickness of the crimped joint can be suppressed from being reduced, the thickness of the crimped joint can be reduced and cracking of the crimped joint can be suppressed. In addition, since the first conductive member and the second conductive member are disposed in the main current path, it is possible that a large current flows and the crimped joint melts when the crimped joint becomes thinner. It can be suppressed. As described above, according to the method of manufacturing the storage element, it is possible to suppress damage to the bonding portion of the two conductive members.

  A storage element according to an aspect of the present invention is a storage element including an electrode body, and includes a first conductive member and a second conductive member disposed in a path of current flowing through the electrode body and joined to each other. The first conductive member and the second conductive member have a caulking joint portion formed of a concavo-convex structure in which either one protrudes toward the other, and the caulking joint portion has a concave portion recessed from the surface. It is formed.

  According to this, in the storage element, the first conductive member and the second conductive member disposed in the path of the current flowing through the electrode body and joined to each other have a caulking joint, and the caulking joint has a surface from the surface A recessed recess is formed. That is, if a concave portion is formed in the caulking joint portion of the first conductive member and the second conductive member, oil is released to the concave portion even if oil is accumulated between the die and the punch in the caulking joint. be able to. For this reason, it can suppress that the oil between a die | dye and punch presses a crimp joint, and it can suppress that the thickness of a crimp joint becomes thin. If the thickness of the crimped joint can be suppressed from being reduced, the thickness of the crimped joint can be reduced and cracking of the crimped joint can be suppressed. In addition, since the first conductive member and the second conductive member are disposed in the main current path, it is possible that a large current flows and the crimped joint melts when the crimped joint becomes thinner. It can be suppressed. Thus, according to the storage element, it is possible to suppress damage to the joint portion of the two conductive members.

  Further, in the caulking joint portion, the one has a first protrusion projecting in a first direction toward the other, and the first protrusion protrudes in a second direction intersecting the first direction. May have a second protrusion.

  According to this, in the caulking joint portion, the first projecting portion projecting in the first direction has the second projecting portion projecting in the second direction intersecting with the first direction. Here, in order to improve the bonding strength of the first conductive member and the second conductive member, in the crimp joint, a second protrusion is formed on the first protrusion to perform a clinching and caulking in an interlock shape. Is preferred. However, when performing clinching and caulking, a large force is applied to the caulking joint, so if oil above the specified amount is accumulated between the die and the punch, the thickness of the caulking joint becomes thinner. The problem becomes noticeable. Therefore, by applying the configuration of the present application, it is possible to perform clinching and caulking while suppressing the thickness of the caulking joint from being reduced. If the clinching and caulking bonding can be performed, the bonding strength of the two conductive members can be improved, and thus the damage of the bonding portion between the two conductive members can be further suppressed.

  Further, the recess may have a non-circular shape as viewed in the normal direction of the surface.

  According to this, the recess of the caulking joint has a non-circular shape. Thereby, at the time of caulking bonding, the oil can be released to the non-circular recess of the caulking joint, so the oil can be released far along the longitudinal direction of the recess. If the oil can be released far, the oil between the die and the punch can be restrained from pressing the caulking joint, so that the thickness of the caulking joint is suppressed from being reduced, and the two conductive members Damage to the joints of the

  Further, the recess may be a groove or a slit formed in at least one of the first conductive member and the second conductive member.

  According to this, the concave portion of the caulking joint is a groove or a slit formed in at least one of the first conductive member and the second conductive member. That is, by forming a groove or a slit in at least one of the first conductive member and the second conductive member and performing caulking bonding, a linear concave portion is formed in the caulking bonding portion. Thereby, at the time of caulking and bonding, the oil can be released to the linear recess of the caulking joint portion, so the oil can be released far along the linear recess. If the oil can be released far, the oil between the die and the punch can be restrained from pressing the caulking joint, so that the thickness of the caulking joint is suppressed from being reduced, and the two conductive members Damage to the joints of the

  Further, the recess may be formed on the surface of the side wall adjacent to the protruding protruding wall of the caulking joint.

  According to this, the recess of the caulking joint is formed on the surface of the side wall adjacent to the projecting wall. Thereby, at the time of caulking bonding, the oil can be released to the recessed portion of the side wall from the location where the oil between the die and the punch in the vicinity of the protruding wall of the caulking joint accumulates. If the oil can be released to the recess of the side wall, the oil can be suppressed from being accumulated between the die and the punch, so that the thickness of the caulking joint can be suppressed from being reduced, and the two conductive members can be joined. It is possible to suppress damage to the part.

  The recess may be formed from the surface of the protruding wall of the caulking joint to the surface of the side wall.

  According to this, the recess of the caulking joint is formed from the protruding wall to the side wall. Thus, at the time of caulking bonding, the oil can be released to the recess of the protruding wall of the caulking joint and can be released to the recess of the side wall from the recess of the protruding wall. If oil can be released to the recessed portions of the projecting wall and the side wall, the oil can be prevented from accumulating between the die and the punch, so that the thickness of the caulking joint can be suppressed from being reduced, and two conductive Damage to the joint of the members can be suppressed.

  Further, a welded portion of the first conductive member and the second conductive member may be formed in the recess.

  According to this, the welded portion of the first conductive member and the second conductive member is formed in the concave portion of the caulking joint portion. Thus, the welding strength of the first conductive member and the second conductive member can be improved by welding the first conductive member and the second conductive member in the concave portion of the caulking joint. That is, the concave portion of the caulking joint can double as a function of releasing the oil and reinforcing the joint strength. This can further suppress damage to the joint portion between the two conductive members.

  Further, the electrode body has stacked electrode plates, the first conductive member is a stacked electrode plate of the electrode body, and the second conductive member is a current collector. It is also good.

  According to this, the first conductive member is an electrode plate on which the electrode body is stacked, and the second conductive member is a current collector. Here, when the electrode body and the current collector are crimped and joined, a high effect can be obtained by using the configuration of the present application. That is, since the electrode plate of the electrode body is thin, it may be damaged if it is compressed too much, but by applying the configuration of the present application, it is possible to suppress the thickness of the electrode body from becoming too thin. For this reason, it is possible to suppress damage to the electrode plate of the electrode body at the joint portion of the electrode body and the current collector.

  Further, a power storage device according to one aspect of the present invention includes a power storage element, and a first metal member and a second metal member joined to each other, wherein the first metal member and the second metal member are either It has a caulking joint formed of a concavo-convex structure in which one projects toward the other, and the caulking joint has a concave portion recessed from the surface.

  According to this, in the power storage device, the first metal member and the second metal member joined to each other have the caulking joint portion, and the caulking joint portion is formed with the concave portion recessed from the surface. That is, if the concave portion is formed in the caulking joint portion of the first metal member and the second metal member, the oil is released to the concave portion even when the oil is accumulated between the die and the punch in the caulking joint. be able to. For this reason, it can suppress that the oil between a die | dye and punch presses a crimp joint, and it can suppress that the thickness of a crimp joint becomes thin. If the thickness of the crimped joint can be suppressed from being reduced, the thickness of the crimped joint can be reduced and cracking of the crimped joint can be suppressed. In addition, when the first metal member and the second metal member are disposed in the main current path, the thickness of the crimped joint is reduced so that a large current flows to cause the crimped joint to melt off. It is possible to suppress As described above, in the two metal members included in the power storage device, damage to the bonding portion between the two metal members can be suppressed.

  Further, a power storage device according to another aspect of the present invention includes a power storage element, and a first plate portion and a second plate portion joined to each other, wherein the first plate portion and the second plate portion are either It has a caulking joint portion formed of a concavo-convex structure in which one side projects toward the other, and the caulking joint portion is formed with a concave portion which is recessed from the surface.

  According to this, in the power storage device, the first plate portion and the second plate portion joined to each other have a caulking joint portion, and the caulking joint portion is formed with a concave portion recessed from the surface. That is, if the concave portion is formed in the caulking joint portion of the first plate portion and the second plate portion, the oil is released to the concave portion even if the oil is accumulated between the die and the punch in the caulking joint. be able to. For this reason, it can suppress that the oil between a die | dye and punch presses a crimp joint, and it can suppress that the thickness of a crimp joint becomes thin. If the thickness of the crimped joint can be suppressed from being reduced, the thickness of the crimped joint can be reduced and cracking of the crimped joint can be suppressed. As described above, in the two plate portions of various materials included in the power storage device, it is possible to suppress damage at the joint portion between the two plate portions.

  The present invention can not only be realized as a method of manufacturing such an electric storage device, an electric storage device or an electric storage device, but also two conductive members (a first conductive member and a second conductive member) and two metal members ( It can also be realized as a caulking joint member provided with a first metal member and a second metal member) or two plate portions (a first plate portion and a second plate portion). The present invention can also be realized as a method of bonding the two conductive members, the two metal members, or the two plate portions (a method of forming a crimped joint).

  According to the manufacturing method of the storage element in the present invention, etc., it is possible to suppress the damage of the bonding portion of the two conductive members.

It is a perspective view which shows the external appearance of the electrical storage element which concerns on embodiment. It is a perspective view which shows the component arrange | positioned inside the container of the electrical storage element which concerns on embodiment. It is a disassembled perspective view which disassembles the electrical storage element which concerns on embodiment, and shows each component. It is sectional drawing which shows the structure in the state by which the positive electrode collector which concerns on embodiment was joined to the positive electrode focusing | converging part of an electrode body. It is a perspective view which shows the structure of the crimp joint part of the positive electrode collector and electrode body which concern on embodiment. It is sectional drawing which shows the internal structure of the crimp joining part of the positive electrode collector and electrode body which concern on embodiment. It is sectional drawing which shows the internal structure of the crimp joining part of the positive electrode collector and electrode body which concern on embodiment. It is a figure explaining the formation method of the crimp joint part concerning embodiment. It is a perspective view which shows the structure of the crimp connection part which concerns on the modification 1 of embodiment. It is a perspective view which shows the structure of the crimp connection part which concerns on the other form of the modification 1 of embodiment. It is a perspective view which shows the structure of the crimp connection part which concerns on the modification 2 of embodiment. It is a perspective view which shows the structure of the crimp joint part which concerns on the modification 3 of embodiment. It is sectional drawing which shows the internal structure of the crimp connection part which concerns on the other form of the modification 3 of embodiment.

  Hereinafter, with reference to the drawings, a method of manufacturing an electricity storage device, an electricity storage device, and an electricity storage device according to an embodiment (and its modification) of the present invention will be described. The embodiments described below are all inclusive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, the manufacturing process, the order of manufacturing processes, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. Further, among the components in the following embodiments, components not described in the independent claim indicating the highest concept are described as arbitrary components. Further, in the drawings, the dimensions and the like are not strictly illustrated.

  Further, in the following description and drawings, the arrangement direction of the pair of electrode terminals included in the storage element, the arrangement direction of the pair of current collectors, the arrangement direction of both end portions of the electrode body (a pair of active material layers not formed) The winding axial direction of the electrode body, the width direction of the legs of the current collector, or the opposing direction of the short side of the container is defined as the X-axis direction. In addition, the opposite direction of the long side of the container, the short direction of the short side of the container, the thickness direction of the container, the lamination direction of the electrode plates of the electrode assembly at the caulking joint, or the current collector and the electrode The alignment direction of the and the cover members is defined as the Y-axis direction. Further, the direction in which the container body and the lid of the storage element are aligned, the longitudinal direction of the short side of the container, or the extending direction of the leg portion of the current collector is defined as the Z-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are directions intersecting with each other (orthogonal in the present embodiment). Further, in the following description, for example, the X axis direction plus side indicates the arrow direction side of the X axis, and the X axis direction minus side indicates the opposite side to the X axis direction plus side. The same applies to the Y-axis direction and the Z-axis direction.

Embodiment
[1. General Description of Storage Element 10]
First, general description of the storage element 10 according to the present embodiment will be given using FIGS. 1 to 3. FIG. 1 is a perspective view showing the appearance of a storage element 10 according to the present embodiment. Moreover, FIG. 2 is a perspective view which shows the component arrange | positioned inside the container 100 of the electrical storage element 10 which concerns on this Embodiment. Specifically, FIG. 2 is a perspective view showing a configuration in which the container body 111 is separated from the 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 decomposing the storage element 10 according to the present embodiment. That is, the figure shows a state before the positive electrode current collector 500 and the negative electrode current collector 600 are bonded to the electrode body 400. Moreover, in the figure, the container main body 111 is abbreviate | omitted and shown in figure.

  The storage element 10 is a secondary battery capable of charging and discharging electricity, and specifically, a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The storage element 10 is used, for example, as a power supply for vehicles such as an electric vehicle (EV), a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV), a power supply for electronic devices, a power supply for power storage, and the like. The 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. In addition, the storage element 10 may not be a secondary battery, but may be a primary battery that can use the stored electricity without charging by the user. Further, although the rectangular parallelepiped (square) storage element 10 is illustrated in the present embodiment, the shape of the storage element 10 is not limited to the rectangular shape, and may be other than a cylindrical shape, a long cylindrical shape, or a rectangular solid. It may be in the shape of a polygonal column or the like, or may be a laminate type storage element.

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

  Although a gasket or the like is disposed 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 enhance the insulation and air tightness, in FIG. The illustration is omitted. The same applies to the negative electrode side. Moreover, although the electrolyte solution (non-aqueous electrolyte) is enclosed in the inside of the container 100, illustration is abbreviate | omitted. In addition, as the said electrolyte solution, if it does not impair the performance of the electrical storage element 10, there will be no restriction | limiting in particular in the kind, Various things can be selected. In addition to the above components, a spacer disposed on the side of the positive electrode current collector 500 and the negative electrode current collector 600, a gas discharge valve for releasing the pressure when the pressure in the container 100 is increased, Alternatively, an insulating film or the like that wraps the electrode body 400 or the like may be disposed.

  The container 100 is configured of a container body 111 having a rectangular cylindrical bottom and a bottom, and a lid 110 which is a plate-like member for closing the opening of the container body 111. In addition, the container 100 can seal the inside by welding the lid 110 and the container main body 111 after the electrode body 400 and the like are accommodated therein. The material of the lid 110 and the container main body 111 is not particularly limited, and may be, for example, a weldable metal such as stainless steel, aluminum, or an aluminum alloy, but a resin may also be used.

  The electrode assembly 400 includes a positive electrode plate, a negative electrode plate, and a separator, and is a 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-like current collector foil made of aluminum, 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-like current collector foil made of copper, copper alloy or the like. In addition, well-known materials, such as nickel, iron, stainless steel, titanium, baked carbon, a conductive polymer, conductive glass, an Al-Cd alloy, can also be used suitably as said current collector foil. In addition, 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 capable of inserting and extracting lithium ions. Moreover, the separator can use the microporous sheet and non-woven fabric which consist of resin, for example.

  The electrode body 400 is formed by arranging and winding a separator between the positive electrode plate and the negative electrode plate. Specifically, in the electrode body 400, the positive electrode plate and the negative electrode plate are wound so as to be mutually shifted in the direction of the winding axis (virtual axis parallel to the X-axis direction in this embodiment) via the separator. ing. And a portion (active material layer non-forming portion) where the active material is not coated (the active material layer is not formed) on the end of each of the positive electrode plate and the negative electrode plate in the shifted direction (the active material layer is not formed) )have.

  That is, the electrode assembly 400 has stacked electrode plates (a positive electrode plate and a negative electrode plate). The electrode body 400 has the positive electrode focusing portion 410 in which the active material layer non-formed portion of the positive electrode plate is stacked and bundled at one end in the winding axial direction (the end on the positive side in the X axis direction). There is. In addition, the electrode body 400 has the negative electrode focusing portion 420 in which the active material layer non-formed portion of the negative electrode plate is stacked and bundled at the other end portion in the winding axial direction (the end portion on the negative side in the X axis direction). ing. For example, the thickness of the active material layer non-forming portion (current collecting 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 sheets, for example, positive electrode focusing portion 410 and negative electrode focusing The part 420 is formed. In the present embodiment, an oval shape is illustrated as the cross-sectional shape of the electrode body 400, 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, positive electrode terminal 200 and negative electrode terminal 300 lead the electricity stored in electrode assembly 400 to the external space of storage element 10, and the electricity in the internal space of storage device 10 for storing electricity in electrode assembly 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 disposed above the electrode assembly 400. Specifically, as shown in FIG. 3, in the positive electrode terminal 200, the protrusion 210 is inserted into the through hole 110a of the lid 110 and the opening 511 of the positive electrode current collector 500 and caulking is performed. 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 disposed between the positive electrode focusing portion 410 of the electrode body 400 and the side wall of the container body 111, and has conductivity and rigidity electrically connected to the positive electrode terminal 200 and the positive electrode plate of the electrode body 400. And a member provided with In addition, the negative electrode current collector 600 is disposed between the negative electrode focusing portion 420 of the electrode body 400 and the sidewall 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. And the rigidity.

  Specifically, the positive electrode current collector 500 and the negative electrode current collector 600 are 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. In addition, the positive electrode current collector 500 and the negative electrode current collector 600 are fixedly connected (joined) to the stacked electrode plates of the electrode assembly 400, that is, the positive electrode focusing portion 410 and the negative electrode focusing portion 420. With this configuration, the electrode assembly 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 or impact is suppressed.

  Although the material of the positive electrode current collector 500 is not limited, for example, like the positive electrode base layer of the electrode assembly 400, it is formed of aluminum or an aluminum alloy. Also, the material of the negative electrode current collector 600 is not limited, but, for example, like the negative electrode base layer of the electrode assembly 400, it is formed of copper or a copper alloy.

[2 Description of crimp joint]
[2.1 Description of configuration around caulking joint 20]
Here, as shown in FIG. 2, the positive electrode current collector 500 is joined to the positive electrode focusing portion 410 of the electrode assembly 400 at a plurality of caulking joints 20. The negative electrode current collector 600 is bonded to the negative electrode focusing portion 420 of the electrode assembly 400 at a plurality of caulking bonding portions 30. The schematic configuration around the caulking joints 20 and 30 will be described below with reference to FIG. In addition, since the caulking joint 20 on the positive electrode side and the caulking joint 30 on the negative electrode side have the same configuration, in the following, the configuration around the caulking joint 20 on the positive electrode side will be described. The description of the configuration around the side caulking joint 30 is omitted.

  FIG. 4 is a cross-sectional view showing a configuration in which positive electrode current collector 500 according to the present embodiment is joined to positive electrode focusing portion 410 of electrode assembly 400. Specifically, this figure shows the configuration in the case where the positive electrode current collector 500 and the positive electrode focusing portion 410 shown in FIG. 2 are cut along the 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 connections extending from both end portions of the terminal connection portion 510 in the Y-axis direction toward the negative side in the Z-axis direction. And a part 520.

  The terminal connection portion 510 is a base of the positive electrode current collector 500 connected (joined) to the positive electrode terminal 200. That is, the terminal connection portion 510 is a flat plate-like portion disposed on the positive electrode terminal 200 side (upper side, positive side in the Z-axis direction) of the positive electrode current collector 500, and is electrically and mechanically connected to the positive electrode terminal 200. Ru.

  The electrode connection portion 520 is a leg portion of the positive electrode current collector 500 connected (joined) to the electrode body 400. That is, the electrode connection portion 520 is a portion disposed on the electrode body 400 side (lower side, the negative side in the Z-axis direction) of the positive electrode current collector 500, and is electrically and mechanically connected to the electrode body 400. Specifically, the electrode connection portion 520 is a long and flat portion extending in the Z-axis direction, and in two positive flat focusing portions of the positive electrode focusing portion 410 of the electrode assembly 400, two electrode flat portions are provided. The electrode connection parts 520 are respectively joined.

  Further, as shown in FIG. 4, a cover member 700 is disposed inside the positive electrode focusing portion 410. The cover member 700 is a cover that is disposed at a position sandwiching the positive electrode focusing portion 410 with the electrode connection portion 520 and that protects the positive electrode focusing portion 410. Specifically, the cover member 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 to have a uniform thickness before bonding. There is. The material of the cover member 700 is not particularly limited. For example, the cover member 700 is a metal member formed of aluminum or an aluminum alloy as in the case of the positive electrode base layer of the electrode assembly 400. A cover member is similarly disposed on the negative electrode side, and the material of the cover member on the negative electrode side is not particularly limited. For example, like the negative electrode base layer of the electrode assembly 400, copper or copper alloy It is a metal member formed by

  Then, the electrode connection portion 520, the positive electrode focusing portion 410, and the cover member 700 are mechanically joined to form four (two for each of the two electrode connection portions 520) caulking joints 20. That is, the caulking joint portion 20 is a joint portion formed in a concavo-convex structure in which one of the stacked electrode plate of the electrode body 400 and the positive electrode current collector 500 protrudes toward the other. Further, the caulking joint portion 20 is a joint portion formed of a concavo-convex structure in which one of the stacked electrode plate of the electrode body 400 and the cover member 700 protrudes toward the other.

  Specifically, caulking joint 20 is a joint of a concavo-convex structure in which electrode connection portion 520 protrudes toward positive electrode focusing portion 410, and electrode connection portion 520 and positive electrode focusing portion 410 are fitted with each other and are joined. It is done. The caulking joint portion 20 is a joint portion of a concavo-convex structure in which the positive electrode focusing portion 410 protrudes toward the cover member 700, and the positive electrode focusing portion 410 and the cover member 700 are fitted and joined to each other. The caulking joint 20 can be formed, for example, by caulking the electrode connection portion 520, the positive electrode focusing portion 410, and the cover member 700 (specifically, by performing a clinching caulking joint).

  Here, the laminated electrode plate of the electrode body 400 and the positive electrode current collector 500 are an example of a first conductive member and a second conductive member. That is, the laminated electrode plate of the electrode assembly 400 and the positive electrode current collector 500 are an example of the first conductive member and the second conductive member which are disposed in the path of the current flowing through the electrode assembly 400 and joined to each other. Further, the stacked electrode plate of the electrode body 400 and the cover member 700 are also examples of the first conductive member and the second conductive member. That is, the laminated electrode plate of the electrode assembly 400 and the cover member 700 are also disposed in the path of the current flowing through the electrode assembly 400 and are an example of the first conductive member and the second conductive member joined to each other. The current flowing through the electrode body 400 is a charging current or a discharging current (main current), and is a current flowing between the electrode body 400 and the positive electrode terminal 200 and the negative electrode terminal 300. Further, the path of the current is a current path between the electrode body 400 and the positive electrode terminal 200 and the negative electrode terminal 300.

  Further, the caulking joint portion 20 is a cylindrical projecting portion, and is disposed so as to project toward each other at a position where the two caulking joint portions 20 face each other. That is, the first conductive member and the second conductive member have two (two pairs) of a pair of caulking joint portions 20 at opposing positions in the Y-axis direction. A detailed description of the configuration of the caulking joint 20 will be described later.

[2.2 Detailed Description of Configuration of Caulking Joint 20]
Next, the configuration of the caulking joint 20 will be described in more detail. FIG. 5 is a perspective view showing a configuration of caulking joint portion 20 between positive electrode current collector 500 and electrode assembly 400 according to the present embodiment. Specifically, this figure is a perspective view of the crimped joint 20 shown in FIG. 4 as viewed from the cover member 700 side (projecting side). 6A and 6B are cross-sectional views showing the internal configuration of caulking joint portion 20 between positive electrode current collector 500 and electrode assembly 400 according to the present embodiment. Specifically, FIG. 6A shows a configuration in which the crimped joint 20 shown in FIG. 5 is cut in a cross section including a VIA-VIA line, and FIG. 6B is a crimped joint shown in FIG. 20 shows a configuration in which section 20 is cut at a cross section including a VIB-VIB line.

  As shown in these figures, the electrode connection portion 520 of the positive electrode current collector 500, the positive electrode focusing portion 410 of the electrode body 400, and the cover member 700 have a first protrusion protruding in the first direction in the caulking joint portion 20. A portion (current collector first projecting portion 521, electrode body first projecting portion 411 and cover first projecting portion 701) is provided. That is, any one of the first conductive member and the second conductive member has a first protrusion projecting in the first direction toward the other. Here, the first direction is the direction in which the first protrusion protrudes, that is, the direction from the electrode connection portion 520 toward the cover member 700, and in the present embodiment, it is the plus side in the Y-axis direction. Moreover, the said 1st protrusion part has the 2nd protrusion (The collector 2nd protrusion part 522 and the electrode body 2nd protrusion part 412) which protrudes in the 2nd direction which cross | intersects a 1st 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 the figure).

  The first projection and the second projection are formed, for example, by plastic deformation of the electrode connection portion 520, the positive electrode focusing portion 410, and the cover member 700 in the caulking joint portion 20. In the present embodiment, the electrode connection portion 520, the positive electrode focusing portion 410, and the cover member 700 are formed by caulking (specifically, clinching and caulking) at the caulking joint 20.

  Specifically, in the crimped joint portion 20, the electrode connection portion 520 has a current-collector first projecting portion 521 that protrudes in the first direction toward the positive electrode focusing portion 410. The current-collector first protrusion 521 is a bottomed substantially cylindrical convex portion in which the surface on the positive electrode focusing portion 410 side of the electrode connection portion 520 protrudes toward the positive electrode focusing portion 410. In other words, the current-collector first protrusion 521 has a shape in which the surface on the opposite side (outside) of the electrode connection portion 520 to the positive electrode focusing portion 410 is recessed toward the positive electrode focusing portion 410 side. Further, the current-collector first protrusion 521 has a current-collector second protrusion 522 that protrudes in the second direction. The current collector second projection 522 is an annular top view viewed from the end on the first direction side of the current collector first projection 521 in the second direction over the entire circumference. In addition, the top view here is a case when it sees from the Y-axis direction plus side, for example, when it sees from the Y-axis direction plus side, it has an annular shape when it sees from the Y-axis direction plus side. Say

  Further, in the caulking joint portion 20, the positive electrode focusing portion 410 has an electrode body first projecting portion 411 that protrudes in the first direction toward the cover member 700. The electrode body first projecting portion 411 is a bottomed substantially cylindrical convex portion in which the surface of the positive electrode focusing portion 410 on the cover member 700 side protrudes toward the cover member 700. In other words, the electrode body first protrusion 411 has a shape in which the surface on the electrode connection portion 520 side of the positive electrode focusing portion 410 is recessed toward the cover member 700 side. Further, the electrode body first projecting portion 411 has an electrode body second projecting portion 412 projecting in the first direction and the second direction. The electrode body second projecting portion 412 is an annular top view viewed from the end on the first direction side of the electrode body first projecting portion 411 in the first direction and the second direction over the entire circumference. is there.

  In addition, in the caulking joint portion 20, the cover member 700 has a cover first projecting portion 701 that protrudes in a first direction away from the positive electrode focusing portion 410. The surface of the cover first protrusion 701 on the side (outside) of the cover member 700 opposite to the positive electrode converging portion 410 is a bottomed substantially cylindrical convex portion that protrudes outward. In other words, the cover first protrusion 701 has a shape in which the surface on the positive electrode focusing portion 410 side of the cover member 700 is recessed toward the opposite side to the positive electrode focusing portion 410. Further, the cover first protrusion 701 has a cover second protrusion 702 having an annular top view and protruding toward the first direction at an end on the first direction side.

  The current collector first protrusion 521, the electrode body first protrusion 411, the cover first protrusion 701, the current collector second protrusion 522, the electrode second protrusion 412, and the cover second protrusion 702 The projecting direction is not limited to the above direction, and may be a direction inclined from the above direction, and the projecting shape is not limited to the above. The current collector second projection 522 may also project in the first direction, and the electrode body second projection 412 may not project in the first direction, or the cover second projection The portion 702 may not protrude in the first direction. In addition, although the cover second projecting portion 702 may protrude in the second direction from the end portion on the first direction side of the cover first projecting portion 701, the joining operation is performed by not projecting in the second direction. Later, the crimped joint 20 can be easily removed from the bonding tool die. In this case, the outer diameter of the cover first protrusion 701 (the width in the Z-axis direction in the figure) may be smaller toward the tip in order to make the crimped joint 20 easier to remove from the die.

  With the above-described configuration, the caulking joint portion 20 has a shape having the protruding wall 22 protruding in the first direction and the side wall 23 adjacent to the protruding wall 22. The protruding wall 22 is a disk-shaped upper wall at the first direction side end of the crimp joint 20. That is, the protruding wall 22 has a disk-shaped upper wall at the first direction side end of the current collector first protruding portion 521, a disk-shaped upper wall at the first direction side end of the electrode body first protruding portion 411, And, it is formed of a disk-shaped upper wall of the first direction side end of the cover first projecting portion 701. The side wall 23 is a cylindrical side wall disposed to surround the projecting wall 22. That is, the side wall 23 includes the side wall surrounding the top wall of the current collector first protrusion 521, the side wall surrounding the top wall of the electrode body first protrusion 411, and the side wall surrounding the top wall of the cover first protrusion 701. It is configured.

[2.3 Description of Recess 21 of Caulking Joint 20]
Here, the caulking joint portion 20 is formed with a recess 21 that is recessed from the surface. That is, the caulking joint portion 20 is formed with a recess 21 recessed from at least one of the surface (the outer surface or the inner surface) of the protruding wall 22 and the surface (the outer surface or the inner surface) of the side wall 23. In the present embodiment, the recess 21 is formed on the surface (outer surface) of the projecting wall 22 and the surface (outer surface) of the side wall 23 of the crimp joint 20. Specifically, the recess 21 is formed from the surface (outer surface) of the projecting wall 22 of the crimp joint 20 to the surface (outer surface) of the side wall 23. In addition, since the outer surface of the protruding wall 22 has a shape in which the inside of the cover second protruding portion 702 is recessed by the cover second protruding portion 702, the recess 21 has a shape in which the recess is further recessed in the protruding wall 22. It has become.

  More specifically, in the recess 21, the groove extending in the second direction from the approximate center of the outer surface of the protruding wall 22 of the crimp joint 20 and the groove extending in the first direction on the outer surface of the side wall 23 are continuously connected It is an L-shaped groove formed by being formed. That is, the L-shaped grooves are formed at four locations on both sides in the X-axis direction and on both sides in the Z-axis direction of the outer surfaces of the protruding wall 22 and the side wall 23 of the caulking joint 20 to configure the recess 21. Thus, the recess 21 has a non-circular shape when viewed from the normal direction of the surface of the crimp joint 20. That is, the recess 21 has a non-circular shape as viewed from the normal direction of the surface (outer surface) of the projecting wall 22 and a non-circular shape as viewed from the normal direction of the surface (outer surface) of the side wall 23. ing.

  Here, the recess 21 is a groove or a slit formed in at least one of the first conductive member and the second conductive member. That is, in the present embodiment, the laminated electrode plate of the electrode body 400 and the cover member 700 are an example of the first conductive member and the second conductive member, and the recess 21 is a slit formed in the cover member 700. . Specifically, the recess 21 is a slit formed from the upper wall of the cover member 700 to the side wall.

[2.4 Description of forming method of caulking joint 20]
Next, of the method of manufacturing the storage element 10, a method of forming the crimped joint portion 20 will be described. FIG. 7 is a view for explaining the method of forming the crimp joint 20 according to the present embodiment. Specifically, (a) in the same figure is a perspective view showing the electrode connection portion 520, the positive electrode focusing portion 410 and the cover member 700 in the state before caulking, and (b) in the same figure is during caulking bonding. FIG. 6C is a cross-sectional view showing the electrode connection portion 520, the positive electrode focusing portion 410 and the cover member 700 in the state after caulking.

  First, as shown to (a) of the figure, the electrode connection part 520, the positive electrode focusing part 410, and the cover member 700 are accumulated and arrange | positioned. At this time, a recess or a through hole is formed in at least one of the first conductive member and the second conductive member (first forming step). In the present embodiment, in the cover member 700, slits that are four linear through holes are formed in an X shape.

  And as shown to (b) of the figure, the die | dye 41 is arrange | positioned under the cover member 700, and the convex punch 42 is arrange | positioned above the electrode connection part 520. FIG.

  Then, as shown in (c) of the same figure, the electrode connection portion 520, the positive electrode focusing portion 410, and the cover member 700 are pressed on the die 41 with a punch 42 from the upper side to place plastic deformation (Screw) That is, the crimped joint portion 20 of the concavo-convex structure in which any one of the first conductive member and the second conductive member protrudes toward the other is formed at the position where the recess or the through hole is formed (second forming step). Specifically, the caulking joint 20 is formed at the position where the slit of the cover member 700 is formed.

  Thereby, in the caulking joint portion 20, while the first protrusion (the current collector first protrusion 521, the electrode body first protrusion 411, and the cover first protrusion 701) is formed, the second protrusion (current collector) is formed. A body second protrusion 522 and an electrode body second protrusion 412) are formed. As described above, by performing caulking bonding (clinching caulking bonding) between the die 41 and the punch 42, the caulking bonding portion 20 can be formed. In the present embodiment, the first protrusion and the second protrusion are formed almost simultaneously by a series of presses, but the first protrusion is formed by the first press, and the second press is formed by the second press. The press may be performed multiple times to form the protrusions.

  Here, after the caulking bonding, oil may be applied to the die 41 and the punch 42 in order to easily peel the caulking joint 20 from the die 41 and the punch 42. In this case, in particular, the die 41 side is Oil may collect in the recess. For this reason, the oil can be released from the recess 21 (slit formed in the cover member 700) of the caulking joint 20 at the caulking joint. For example, the oil can be released to the projecting wall 22 and the recess 21 of the side wall 23 in the path of the broken arrow in (c) of the same figure.

  In the first formation step, not the through hole such as the slit but the concave portion such as the groove is formed in at least one of the first conductive member and the second conductive member (in the present embodiment, the cover member 700). You may That is, the recess 21 of the caulking joint 20 may be a groove formed in at least one of the first conductive member and the second conductive member.

[3 Description of effect]
As described above, according to the method of manufacturing power storage device 10 (the method of forming caulking joint 20) according to the embodiment of the present invention, the first conductive member and the first conductive member arranged in the path of the current flowing through electrode body 400 A recess or a through hole is formed in at least one of the two conductive members, and a caulking joint 20 is formed at a position where the recess or the through hole of the first conductive member and the second conductive member is formed. That is, after forming a recess or a through hole in at least one of the first conductive member and the second conductive member, caulking bonding is performed. Thus, even when oil is accumulated between the die 41 and the punch 42 at the time of caulking and bonding, the oil can be released to the recess or the through hole. For this reason, it can suppress that the oil between the die | dye 41 and the punch 42 presses the crimp joint part 20, and can suppress that the thickness of the crimp joint part 20 becomes thin. If the thickness of the crimped joint 20 can be suppressed from being reduced, the thickness of the crimped joint 20 can be reduced and cracking of the crimped joint 20 can be suppressed. In addition, since the first conductive member and the second conductive member are disposed in the main current path, the thickness of the caulking joint 20 is reduced so that a large current flows and the caulking joint 20 is melted and cut. Can be suppressed. As described above, according to the method of manufacturing the storage element 10, it is possible to suppress damage to the joint portion between the two conductive members.

  Moreover, according to the storage element 10 according to the embodiment of the present invention, the first conductive member and the second conductive member disposed in the path of the current flowing through the electrode body 400 and joined to each other have the caulking joint portion 20. The caulking joint portion 20 is formed with a recess 21 recessed from the surface. That is, as described above, if the recess 21 is formed in the caulking joint portion 20 of the first conductive member and the second conductive member, oil is accumulated between the die 41 and the punch 42 during caulking bonding. Also, the oil can be released to the recess 21. For this reason, according to the storage element 10, it is possible to suppress damage to the joint portion between the two conductive members.

  Further, in the caulking joint portion 20, the first projecting portion projecting in the first direction has the second projecting portion projecting in the second direction intersecting with the first direction. Here, in order to improve the bonding strength of the first conductive member and the second conductive member, in the caulking joint portion 20, a second projecting portion is formed in the first projecting portion to perform clinching caulking in an interlock shape. Is preferred. However, when performing clinching and caulking, a large force is applied to the caulking joint 20, so if oil exceeding a specified amount is accumulated between the die 41 and the punch 42, the thickness of the caulking joint 20 is thin. The problem of becoming Therefore, by applying the configuration of the present application, it is possible to perform the clinching and caulking while suppressing the thickness of the caulking joint 20 from being reduced. If the clinching and caulking bonding can be performed, the bonding strength of the two conductive members can be improved, and thus the damage of the bonding portion between the two conductive members can be further suppressed.

  Moreover, the recessed part 21 of the crimp joint part 20 has a non-circular shape. Thereby, at the time of caulking bonding, the oil can be released to the non-circular recess 21 of the caulking joint 20, so the oil can be released far along the longitudinal direction of the recess 21. Since the oil between the die 41 and the punch 42 can be restrained from pressing the caulking joint 20 if oil can be released far, it is possible to suppress the thinning of the caulking joint 20, Damage to the joint portion between the two conductive members can be suppressed.

  Further, the recess 21 of the caulking joint 20 is a groove or a slit formed in at least one of the first conductive member and the second conductive member. That is, by forming a groove or a slit in at least one of the first conductive member and the second conductive member and performing caulking and bonding, a linear recess 21 is formed in the caulking bonding portion 20. Thereby, at the time of caulking and bonding, the oil can be released to the linear recess 21 of the caulking joint portion 20, so the oil can be released far along the linear recess 21. Since the oil between the die 41 and the punch 42 can be restrained from pressing the caulking joint 20 if oil can be released far, it is possible to suppress the thinning of the caulking joint 20, Damage to the joint portion between the two conductive members can be suppressed.

  The recess 21 of the caulking joint 20 is formed on the surface of the side wall 23 adjacent to the protruding wall 22. Thereby, at the time of caulking and bonding, the oil can be released to the concave portion 21 of the side wall 23 from the portion where the oil between the die 41 and the punch 42 in the vicinity of the protruding wall 22 of the caulking joint 20 is collected. If the oil can be released to the recess 21 of the side wall 23, the oil can be suppressed from being accumulated between the die 41 and the punch 42, so that the thickness of the caulking joint portion 20 is suppressed from being reduced. Damage to the joint portion of the conductive member can be suppressed.

  In addition, the recess 21 of the caulking joint 20 is formed from the projecting wall 22 to the side wall 23. Thus, at the time of caulking and bonding, the oil can be released to the recess 21 of the protruding wall 22 of the caulking joint 20 and can also be released from the recess 21 of the protruding wall 22 to the recess 21 of the side wall 23. If the oil can escape to the projecting wall 22 and the recess 21 of the side wall 23, the oil can be prevented from being accumulated between the die 41 and the punch 42, so that the thickness of the caulking joint 20 can be reduced. Thus, it is possible to suppress damage to the joint portion between the two conductive members.

  The first conductive member is a stacked electrode plate of the electrode body 400, and the second conductive member is a cover member 700. Here, when the electrode body 400 and the cover member 700 are crimped and joined, a high effect can be obtained by using the configuration of the present application. That is, since the electrode plate of the electrode assembly 400 is thin, it may be damaged if it is compressed too much, but by applying the configuration of the present application, it is possible to suppress the thickness of the electrode assembly 400 from being too thin. For this reason, it is possible to suppress damage to the electrode plate of the electrode body 400 in the joint portion of the electrode body 400 and the cover member 700.

  Also, during caulking bonding, the oil between the die 41 and the punch 42 escapes to the recess or through hole formed in at least one of the first conductive member and the second conductive member, so that the oil is scattered. The amount of oil used can be reduced. Furthermore, if it is possible to suppress the oil from being scattered, it is possible to suppress the deterioration of the welding quality when performing the welding operation at or near the caulking joint portion 20.

  The negative electrode current collector 600 side also has the same configuration as that of the positive electrode current collector 500 side, so similar effects can be achieved.

[Description of Modification of Fourth Embodiment]
(Modification 1)
Next, a first modification of the above embodiment will be described. FIG. 8 is a perspective view showing the configuration of a crimp joint 20a according to a first modification of the present embodiment. Moreover, FIG. 9 is a perspective view which shows the structure of the crimp joint part 20b based on the other form of the modification 1 of this Embodiment. Note that these figures correspond to FIG.

  First, as shown in FIG. 8, the caulking joint portion 20a in the present modification has a concave portion 21a in place of the concave portion 21 of the caulking joint portion 20 in the above embodiment. The concave portion 21 a is an X-shaped groove in which the four grooves of the concave portion 21 in the above embodiment are connected at the central portion of the projecting wall 22. That is, the recess 21a crosses the central portion of the projecting wall 22 from the side surface on the positive side in the X axis direction of the side wall 23, and extends from the side surface to the side surface on the negative side in the X axis direction A groove is formed by crossing a central portion of the wall 22 and a groove extending to the side of the side wall 23 on the minus side in the Z-axis direction. The other configuration is the same as that of the above embodiment, and the detailed description will be omitted.

  As described above, by forming the groove also in the central portion of the projecting wall 22, oil can be released from the central portion of the projecting wall 22 to the side surface of the side wall 23 at the time of caulking. Further, by forming the groove also in the central portion of the protruding wall 22, the volume in the recess 21a can be increased, so that a large amount of oil can be released. The length of the recess 21 a is not particularly limited, and may extend halfway to the side of the side wall 23 or may extend below the side wall 23.

  Further, as shown in FIG. 9, the caulking joint portion 20b in another form of the present modification has a concave portion 21b in place of the concave portion 21a of the caulking joint portion 20a of FIG. Unlike the recess 21 a, the recess 21 b has no groove formed in the side wall 23. That is, the recess 21 b is a groove extending from the end of the protruding wall 22 on the positive side in the X-axis direction to the end on the negative side in the X-axis direction, and the end from the positive side in the Z-axis direction to the end on the negative side in the Z-axis It is an X-shaped groove formed by crossing the groove extending to the end. The other configuration is the same as that of the above embodiment, and the detailed description will be omitted.

  As described above, by not forming the groove in the side wall 23, even if the concave portion 21b is formed in the caulking joint portion 20b, it is possible to suppress the decrease in the strength of the caulking joint portion 20b. Although the recess 21 b is not formed on the side wall 23 but is formed on the protruding wall 22, the recess 21 b is not formed on the protruding wall 22 and is formed on the side wall 23. It may be

  As described above, according to the storage element 10 according to the present modification, recessed portions with various shapes can be formed in the caulking joint. In addition, the shape of the said recessed part is not limited to the said embodiment and this modification, For example, the groove | channel of shapes other than X-shape, such as Y-shape and I-shape, may be sufficient, and it is circular instead of a groove. It may be a concave such as an elliptical shape, an oval shape, or a polygonal shape.

(Modification 2)
Next, a second modification of the above embodiment will be described. FIG. 10 is a perspective view showing the configuration of a crimp joint 20c according to a second modification of the present embodiment. The same figure corresponds to FIG.

  As shown in FIG. 10, an X-shaped recess 21b is formed in the caulking joint portion 20c in the present modification as in the caulking joint portion 20b in the first modification. Is formed. That is, the welded portion 24 of the first conductive member and the second conductive member (the positive electrode converging portion 410 and the cover member 700) is formed in the recess 21b. The welding portion 24 is a welding portion formed by, for example, laser welding at an end of the recess 21 b (an end on both sides in the X axis direction and both ends in the Z axis direction). That is, the welding portion 24 is a portion formed by welding the electrode body first projecting portion 411 of the positive electrode focusing portion 410 and the cover first projecting portion 701 of the cover member 700. The other configuration is the same as that of the first modification, and the detailed description is omitted.

  As described above, according to storage element 10 of the present modification, since positive electrode focusing portion 410 is exposed from cover member 700 in recess 21 b, two conductive members (two conductive members The positive electrode focusing portion 410 and the cover member 700 can be easily welded. And in the recessed part 21b of the caulking joining part 20c, the welding strength of two conductive members can be improved by welding two conductive members. That is, the recess 21b of the caulking joint portion 20c can serve two functions of releasing the oil and reinforcing the joint strength. This can further suppress damage to the joint portion between the two conductive members.

  In this modification, the weld portion 24 is formed at the end of the recess 21b, but the position at which the weld portion 24 is formed is not particularly limited, and the weld portion 24 is formed at the central portion of the recess 21b. Alternatively, the welded portion 24 may be formed in the entire recess 21b. In addition, the welding portion 24 may be formed by welding other than laser welding such as ultrasonic welding, resistance welding, arc welding, or electron beam irradiation. Further, the welding portion 24 is not limited to being formed in the recess 21b in the first modification, and can be formed in the recess 21 in the above embodiment, the recess 21a in the first modification, or a recess of other various shapes. It is.

(Modification 3)
Next, a third modification of the above embodiment will be described. FIG. 11 is a perspective view showing a configuration of a crimp joint portion 20d according to the third modification of the present embodiment. In addition, the same figure is the perspective view which looked at the crimp joint part 20d from the electrode connection part 520 side.

  As shown in FIG. 11, in the caulking joint portion 20d in the present modification, a concave portion 21d is formed on the electrode connection portion 520 side. Specifically, the recess 21 d is formed on the surface (inner surface) of the side wall 23 of the caulking joint 20 d. Although not shown, the recess 21 d is also formed on the surface (inner surface) of the projecting wall 22 of the caulking joint 20 d (see FIG. 12). That is, the recess 21 d is formed from the surface (inner surface) of the protruding wall 22 of the crimped joint 20 d to the surface (inner surface) of the side wall 23. The other configuration is the same as that of the above embodiment, and the detailed description will be omitted.

  As described above, in the present modification, the stacked electrode plate of the electrode body 400 and the positive electrode current collector 500 are an example of the first conductive member and the second conductive member, and the recess 21 d is formed in the electrode connection portion 520. Grooves or slits. Specifically, the recess 21 d is a slit formed from the upper wall of the electrode connection portion 520 to the side wall.

  As described above, in the storage element 10 according to the present modification, the thickness of the electrode body 400 becomes too thin when the electrode body 400 and the positive electrode current collector 500 are crimped and joined as in the above embodiment. Can be suppressed. For this reason, it is possible to suppress damage to the electrode plate of the electrode body 400 in the joint portion of the electrode body 400 and the positive electrode current collector 500.

  In the present modification, as in the above embodiment, a recess may be formed on the cover member 700 side of the caulking joint. That is, by forming grooves or slits in both the positive electrode current collector 500 and the cover member 700, recesses may be formed on both surfaces (inner surface and outer surface) of the crimped joint.

  Further, in the present modification, the storage element 10 may not include the cover member 700. FIG. 12 is a cross-sectional view showing an internal configuration of a crimp joint portion 20e according to another form of the third modification of the present embodiment. The figure corresponds to FIG. 6B. That is, the crimped joint 20 e shown in FIG. 12 is obtained by removing the cover member 700 from the crimped joint 20 d. The other configuration is the same as that of the caulking joint 20d, and the detailed description will be omitted.

(Modification 4)
In the above embodiment and its modification, the first conductive member and the second conductive member are the electrode plate and the cover member 700 on which the electrode assembly 400 is laminated, or the electrode plate and the collector on which the electrode assembly 400 is laminated. (Positive electrode current collector 500 or negative electrode current collector 600) However, the first conductive member and the second conductive member are not particularly limited as long as they are members disposed in the path of the current flowing through the electrode body 400 and joined to each other. For example, when a conductive member such as a lead is disposed between the electrode body 400 and the current collector, the first conductive member and the second conductive member may be the electrode body 400 and the conductive member. , A current collector and the conductive member.

  When the electrode terminal (positive electrode terminal 200 or negative electrode terminal 300) is formed of two members, the first conductive member and the second conductive member may be the two members constituting the electrode terminal. When the current collector (the positive electrode current collector 500 or the negative electrode current collector 600) is composed of two members, the first conductive member and the second conductive member constitute the current collector. It may be In addition, the first conductive member and the second conductive 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 conductive member and the second conductive member may be the electrode terminal and the container 100, or may be the current collector and the container 100. .

  In addition, the first conductive member and the second conductive member may be included in a storage device (a module including a plurality of storage devices 10 or a pack including a plurality of the modules) including the storage device 10. For example, when the first conductive member and the second conductive member are provided in the module, the first conductive member and the second conductive member may be a bus bar between the electrode terminal of the storage element 10 and the storage element 10, or It may be an external terminal of a bus bar and a module connected to the 10 electrode terminals, or the two members in the case where these bus bars are formed by two members. In addition, when the first conductive member and the second conductive member are provided in the pack, the first conductive member and the second conductive member are connected to the external terminal of the module and the bus bar between the modules or the external terminal of the module It may be an external terminal of the bus bar and the pack, or may be the two members in the case where these bus bars are formed by two members. When the storage device is provided with a relay or a fuse, the first conductive member and the second conductive member may be a bus bar and a relay, or a bus bar and a fuse. Also in these cases, the configurations of the first conductive member and the second conductive member and the effects thereof are the same as those of the above-described embodiment and the modifications thereof.

  Furthermore, the first conductive member and the second conductive member are two metal members not disposed in the path of the current flowing through the electrode body 400 in the module or the pack (the first metal member and the second metal member joined to each other) ) May be. For example, as a first conductive member and a second conductive member, an end plate disposed at both ends of a plurality of storage elements 10 and sandwiching the plurality of storage elements 10 and a plurality of storage elements 10 connected to the end plate Constraint bars etc. can be considered. Alternatively, as the first conductive member and the second conductive member, an exterior body main body and a lid of an exterior body that accommodates a plurality of power storage devices 10 may be considered. In addition, the first conductive member and the second conductive member may be two adjacent casings (two adjacent module cases, two adjacent pack cases, etc.).

  Also, the first conductive member and the second conductive member are not two metal members, but two plate portions other than metal members such as reinforced plastic in a module or pack (first plate portion and second plate joined to each other Part). For example, as the first conductive member and the second conductive member, the above-described end plate and restraining bar, the outer package main body and lid of the outer package, and the like can be considered. In addition, the first conductive member and the second conductive member may be two adjacent casings (two adjacent module cases, two adjacent pack cases, etc.).

  As described above, according to power storage device 10 and the power storage device of the present modification, various members can be applied as the first conductive member and the second conductive member. That is, according to the storage element 10 according to the present modification, as in the above-described embodiment, damage to the joint portion between the two conductive members can be suppressed. Further, according to the power storage device of the present modification, it is possible to suppress damage to the joint portion between the two conductive members, the two metal members, or the two plate portions. In addition, since caulking bonding can be performed without using a component for bonding, the number of components constituting the power storage device can be reduced.

(Other modifications)
As mentioned above, although the electrical storage element 10 which concerns on embodiment and its modification of this invention was demonstrated, this invention is not limited to this embodiment and its modification. That is, it should be understood that the embodiment disclosed this time and the modification thereof are illustrative in all points and not restrictive. The scope of the present invention is indicated not by the above description but by the claims, and is intended to include all the modifications within the meaning and scope equivalent to the claims.

  For example, in the above-mentioned embodiment and its modification, it was decided that a pair of caulking joints are arranged at mutually opposing positions. However, the crimped joints do not have to be arranged at opposite positions. Also, the number of caulking joints is not particularly limited, and any number of caulking joints may be formed in the electrode connection portion 520. Further, the number of the electrode connection portions 520 is not limited, and the positive electrode current collector 500 may have only one electrode connection portion 520, and has three or more electrode connection portions 520. You may decide to In addition, when the electrode connection part 520 is made into one, since the die | dye 41 and the punch 42 are easy to arrange | position on both sides of the electrode connection part 520, a crimp joint part can be formed easily.

  Further, in the above-described embodiment and the modification thereof, the positive electrode current collector 500 has the caulking joint portion formed on both of the two electrode connection portions 520, but any one of the electrode connection portions 520 The configuration may be such that a crimp joint is formed. Further, in the storage element 10, the caulking bonding portion is formed on both of the positive electrode current collector 500 and the negative electrode current collector 600. However, one of the positive electrode current collector 500 and the negative electrode current collector 600 The configuration may be such that a crimp joint is formed.

  Moreover, in the said embodiment and its modification, it decided that the crimp junction part protruded to the Y-axis direction plus side. That is, the crimped joint portion is a joint portion of a concavo-convex structure in which the positive electrode current collector 500 protrudes toward the electrode body 400 and the cover member 700. However, the caulking joint may be a joint of a concavo-convex structure in which the cover member 700 and the electrode assembly 400 protrude toward the positive electrode current collector 500. For example, in the case where the cover member 700 is thicker than the positive electrode current collector 500, this configuration is preferable. Alternatively, the crimped joint may be crushed in the height direction (Y-axis direction) and may not have a shape projecting outward.

  Moreover, in the said embodiment and its modification, it was decided that the caulking joint part had a top view circular shape. However, the caulking joint may have an oval shape, an oval shape, a polygonal shape, or the like in top view.

  Further, in the above-described embodiment and the modification, the electrode assembly 400 is a so-called longitudinally wound winding-type electrode assembly in which the winding axis is parallel to the lid 110. However, the electrode assembly 400 may be a so-called laterally wound winding electrode assembly in which the winding axis is perpendicular to the lid 110. Further, the shape of the electrode body 400 is not limited to the winding type, and may be a stack type in which flat plate-like electrode plates are stacked, or a shape in which the electrode plates are folded in a bellows shape.

  Further, in the above-described embodiment and its modification, although the positive electrode current collector 500, the electrode assembly 400, and the cover member 700 are joined, members other than these may be joined together. .

  Further, in the above-described embodiment and the modified example thereof, clinching and caulking is illustrated as an example of plastically deforming the positive electrode current collector 500, the electrode assembly 400, and the cover member 700 when they are joined. However, the present invention is not limited to this, and bonding by caulking in a form different from clinching caulking may be used.

  Moreover, the present invention can not only be realized as a method of manufacturing such a storage element 10, storage element 10 or storage device, but also two conductive members (first conductive member and second conductive member), two metals It can also be realized as a caulking joint member including a member (a first metal member and a second metal member) or two plate portions (a first plate portion and a second plate portion). The caulking bonding member may or may not be included in the storage element 10 or the storage device. For example, in the case where the caulking joint member includes two plate portions, the caulking joint member includes a first plate portion and a second plate portion which are joined to each other, and the first plate portion and the second plate portion are either It has a crimped joint formed of a concavo-convex structure in which one projects toward the other, and the crimped joint has a recess recessed from the surface.

  Also with this configuration, the same effects as those of the storage element 10 or the storage device can be obtained. That is, as described above, damage to the joint portion of the two plate portions in the caulking joint member can be suppressed, and the amount of oil used in caulking joint can be suppressed by suppressing oil from scattering. Can be reduced. Furthermore, by suppressing the oil from scattering, it is possible to reduce the cause of problems in the process after caulking. The reduction of the cause of the failure is, for example, as follows. In recent years, with the increasing use of aluminum materials for the purpose of reducing the weight of vehicles, resistance welding used in conventional joining is difficult to adopt, and caulking joining by plastic deformation is beginning to be adopted. At the same time, opportunities to carry out partial welding such as laser welding have been increased to improve the rigidity of the vehicle, and scattering of oil at the time of caulking causes a decrease in welding quality. On the other hand, in the present invention, since it can control that oil splashes, this welding quality fall can be controlled.

  The same applies to the case where the caulking joint member includes two conductive members or two metal members. The present invention can also be realized as a method of bonding the two conductive members in the caulking bonding member, the two metal members, or the two plate portions (a method of forming a caulking bonding portion).

  Further, a form constructed by arbitrarily combining the components included in the above-described embodiment and the modification thereof is also included in the scope of the present invention.

  The present invention is applicable to storage devices such as lithium ion secondary batteries.

DESCRIPTION OF SYMBOLS 10 storage element 20, 20a, 20b, 20c, 20d, 30 junction part 21, 21a, 21b, 21d recessed part 22 protruding wall 23 side wall 24 welding part 400 electrode body 410 positive electrode focusing part 411 electrode body first protruding part 412 electrode Body second protrusion 420 negative electrode focusing portion 500 positive electrode current collector 520 electrode connection portion 521 current collector first protrusion 522 current collector second protrusion 600 negative electrode current collector 700 cover member 701 cover first protrusion 702 cover Second protrusion

Claims (12)

A method of manufacturing a storage element, comprising: a first conductive member and a second conductive member disposed in a path of current flowing through an electrode body and joined to each other,
Forming a recess or a through hole in at least one of the first conductive member and the second conductive member;
Forming a crimped joint of a concavo-convex structure in which any one of the first conductive member and the second conductive member protrudes toward the other at a position where the recess or the through hole is formed; Method of manufacturing a storage element including the same. A storage element comprising an electrode body,
And a first conductive member and a second conductive member disposed in a path of current flowing through the electrode body and joined to each other,
Each of the first conductive member and the second conductive member has a caulking joint formed of a concavo-convex structure in which one of the first conductive member and the second conductive member protrudes toward the other,
A concave portion recessed from the surface is formed in the caulking joint portion. In the caulking joint, the one has a first protrusion projecting in a first direction toward the other,
The storage element according to claim 2, wherein the first protrusion includes a second protrusion protruding in a second direction intersecting the first direction. The storage element according to claim 2, wherein the recess has a non-circular shape when viewed from the normal direction of the surface. The electric storage device according to any one of claims 2 to 4, wherein the recess is a groove or a slit formed in at least one of the first conductive member and the second conductive member. The electric storage element according to any one of claims 2 to 5, wherein the concave portion is formed on a surface of a side wall adjacent to a protruding protruding wall of the caulking joint. The storage element according to claim 6, wherein the recess is formed from the surface of the protruding wall of the caulking joint to the surface of the side wall. The storage element according to any one of claims 2 to 7, wherein a welded portion of the first conductive member and the second conductive member is formed in the recess. The electrode body has stacked electrode plates,
The first conductive member is a stacked electrode plate of the electrode body,
The storage element according to any one of claims 2 to 8, wherein the second conductive member is a current collector. A storage element,
A first metal member and a second metal member joined together;
Each of the first metal member and the second metal member has a caulking joint formed of a concavo-convex structure in which one of the first metal member and the second metal member protrudes toward the other,
The electric storage device, wherein the caulking joint portion is formed with a concave portion recessed from the surface. A storage element,
A first plate portion and a second plate portion joined together;
Each of the first plate portion and the second plate portion has a caulking joint formed of a concavo-convex structure in which one of the first plate portion and the second plate portion protrudes toward the other,
The electric storage device, wherein the caulking joint portion is formed with a concave portion recessed from the surface. Comprising a first plate portion and a second plate portion joined together;
Each of the first plate portion and the second plate portion has a caulking joint formed of a concavo-convex structure in which one of the first plate portion and the second plate portion protrudes toward the other,
The caulking joint member has a concave portion recessed from the surface at the caulking joint portion.

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