JP2019121457A - Manufacturing method of power storage device, and power storage device - Google Patents

Abstract

To provide a manufacturing method of a power storage element capable of suppressing the occurrence of a short circuit due to a connection operation between an electrode body and a current collector.SOLUTION: A manufacturing method of a power storage element 10 including an electrode body 400 and a positive electrode current collector 500 having an electrode body connecting portion 520 connected to an end portion on the first direction side of the electrode body 400 includes a resistance welding step of forming a resistance welding portion 700 on an inclined portion 521 by resistance-welding the inclined portion 521 arranged to be inclined with respect to the first direction of the electrode body connecting portion 520 and the end portion 410 of the electrode body 400, and in the resistance welding step, a resistance weld 700 is formed such that the center position of the resistance welding portion 700 is disposed on the first direction side of the center position of the portion in which the electrode connecting portion 520 and the end portion 410 of the electrode body 400 are opposed to each other.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a method of manufacturing an electricity storage device including an electrode body and a current collector, and an electricity storage device.

  2. Description of the Related Art Conventionally, in a storage element including an electrode body and a current collector, a configuration in which the current collector is connected to the electrode body by welding is widely known. For example, Patent Document 1 discloses a storage element (nonaqueous electrolyte secondary battery) in which a current collector is connected to an electrode body (a wound electrode body) by ultrasonic welding.

JP, 2017-10945, A

  However, in the above-mentioned conventional storage element, there is a problem that a short circuit may occur due to the connection operation of the electrode body and the current collector. That is, in the conventional storage element, since the current collector is connected to the electrode body by ultrasonic welding, metal powder is generated when ultrasonic welding is performed, and the metal powder intrudes into the electrode body. , May cause a short circuit. For this reason, it is conceivable to connect the current collector to the electrode body by resistance welding, but when resistance welding is performed, for example, the separator in the electrode body is shrunk by heat from the welded portion and the positive electrode plate and the negative electrode plate are in contact. This may also cause a short circuit.

  The present invention has been made in view of the above problems, and provides a method of manufacturing a storage element that can suppress the occurrence of a short circuit due to the connection operation between an electrode body and a current collector, and a storage element. The purpose is

  In order to achieve the above object, a method of manufacturing a storage element according to one aspect of the present invention includes an electrode body and a current collector having an electrode body connection portion connected to an end of the electrode body on the first direction side. And manufacturing the storage element by resistance-welding the end of the electrode body with the sloped portion of the electrode body connection portion which is disposed to be inclined with respect to the first direction. A resistance welding step of forming a resistance welding portion in the inclined portion, and in the resistance welding step, a central position of the resistance welding portion faces the electrode body connection portion and an end portion of the electrode body The resistance welding portion is formed to be disposed on the first direction side with respect to the center position of the portion.

  According to this, in the method of manufacturing the storage element, resistance welding is performed by resistance-welding the inclined portion of the electrode connection portion of the current collector disposed on the first direction side of the electrode and the end of the electrode. At the time of formation, the center position of the resistance welding portion is disposed on the first direction side of the center position of the portion where the electrode body connecting portion and the end portion of the electrode body are opposed. Here, the inclined portion is a portion inclined with respect to the first direction in the electrode body connecting portion of the current collector. For this reason, in the range of the same length in the first direction, it is possible to make the length longer by arranging the sloped portion than arranging the sloped portion along the first direction, thereby opposing the sloped portion The length of the end of the electrode body can also be increased. Furthermore, the center position of the resistance welding portion is disposed on the first direction side with respect to the center position of the facing portion between the electrode connection portion and the end portion of the electrode body so as to move the resistance welding portion away from the electrode body Form. As described above, the resistance welding portion is disposed away from the separator of the electrode assembly while the length of the end portion of the electrode assembly is increased. Thus, the distance between the resistance welding portion and the separator can be increased, so that heat from the resistance welding portion can be used to suppress shrinkage of the separator and contact between the positive electrode plate and the negative electrode plate. Therefore, it is possible to suppress the occurrence of a short circuit due to the connection operation between the electrode body and the current collector.

  In addition, the storage element according to one aspect of the present invention includes an electrode body and a current collector disposed on the first direction side of the electrode body, and the current collector is connected to an end portion of the electrode body. An electrode body connection portion, and the electrode body connection portion has an inclined portion which is disposed to be inclined with respect to the first direction and in which a resistance welded portion with the end portion of the electrode body is formed. A central position of the resistance welding portion is disposed on the first direction side of a central position of a portion where the electrode body connection portion and an end portion of the electrode body are opposed.

  According to this, in the storage element, the electrode connection portion of the current collector disposed on the first direction side of the electrode is inclined with respect to the first direction, and the resistance welded portion with the end of the electrode is It has the formed inclined part, and the center position of the resistance welding part is arranged on the first direction side of the center position of the part where the electrode body connecting part and the end of the electrode body are opposed. As a result, since it is possible to make the length longer than when the inclined portion is disposed along the first direction within the same length range in the first direction, the electrode body facing the inclined portion The length of the end of the can also be increased. Furthermore, the center position of the resistance welding portion is disposed on the first direction side with respect to the center position of the facing portion between the electrode connection portion and the end portion of the electrode body so as to move the resistance welding portion away from the electrode body Form. As described above, the resistance welding portion is disposed away from the separator of the electrode assembly while the length of the end portion of the electrode assembly is increased. Thus, the distance between the resistance welding portion and the separator can be increased, so that heat from the resistance welding portion can be used to suppress shrinkage of the separator and contact between the positive electrode plate and the negative electrode plate. Therefore, it is possible to suppress the occurrence of a short circuit due to the connection operation between the electrode body and the current collector.

  Further, the electrode body connection portion is further extended in a second direction side opposite to the first direction of the inclined portion in a direction different from the inclination direction of the inclined portion, and It may be possible to have a first extending portion disposed along the end.

  According to this, in the current collector, the electrode body connection portion is extended in the second direction side opposite to the first direction of the inclined portion in a direction different from the inclination direction of the inclined portion, and the end of the electrode body It has a first extending part along the part. Thus, the electrode body connecting portion has a bent shape by the first extending portion extending in the direction different from the inclination direction of the inclined portion. For this reason, the length of the electrode body connecting portion can be made longer than that of forming the electrode body connecting portion in a straight line, and the length of the end portion of the electrode body can also be made longer. Thus, the distance between the resistance welding portion and the separator can be increased, so that heat from the resistance welding portion can be used to suppress shrinkage of the separator and contact between the positive electrode plate and the negative electrode plate. Therefore, it is possible to suppress the occurrence of a short circuit due to the connection operation between the electrode body and the current collector.

  Moreover, the length in the inclination direction of the inclined portion may be longer than the length in the extending direction of the first extension portion.

  According to this, in the current collector, the length in the inclination direction of the inclined portion of the electrode body connection portion is longer than the length in the extension direction of the first extension portion. Here, since the present application is configured to suppress shrinkage of the separator due to heat from the resistance welding portion, the area of the resistance welding portion can be increased. For this reason, the length of the inclined portion in the inclination direction can be increased to increase the area of the resistance welded portion, whereby the bonding area between the electrode connection portion and the end portion of the electrode can be increased. . Thus, by increasing the bonding area between the electrode connection portion and the end of the electrode, the resistance between the electrode connection and the end of the electrode is reduced, and the electrode connection is formed into the electrode It can be fixed firmly to the end of the

  The first extending portion may extend along the first direction.

  According to this, in the current collector, the first extending portion of the electrode body connecting portion is extended along the first direction, whereby the electrode body connecting portion contacts the electrode body from an oblique direction. Damage to the electrode body can be suppressed. Thus, the electrode body can be prevented from being damaged and the positive electrode plate and the negative electrode plate coming into contact with each other, so that the occurrence of a short circuit resulting from the connection operation between the electrode body and the current collector can be suppressed. it can.

  In addition, the electrode body connection portion further extends in a direction away from the end portion of the electrode body toward the second direction on the second direction side of the first extension portion. You may decide to have a part.

  According to this, in the current collector, the electrode body connecting portion has the second extending portion which is separated from the end portion of the electrode body toward the second direction on the second direction side of the first extending portion. There is. As described above, the second extending portion is extended in the direction away from the end of the electrode body, and the electrode body connecting portion is further bent, whereby the electrode body connecting portion contacts the electrode body. Thus, damage to the electrode body can be further suppressed. In addition, the second extending portion functions as a cooling mechanism, and can release heat generated at the time of welding. As a result, it is possible to further suppress that the electrode body is damaged and the positive electrode plate and the negative electrode plate are in contact with each other, thereby further suppressing the occurrence of short circuit caused by the connection operation of the electrode body and the current collector. be able to.

  Further, an end of the electrode body has two focusing portions in which a plurality of electrode plates are stacked, and the current collector has two inclined portions corresponding to the two focusing portions, The two inclined portions may be arranged to be inclined from the first direction so as to be apart from each other as going in the first direction.

  According to this, the current collector has two slopes corresponding to the two convergent portions at the end of the electrode body, and the two slopes are separated from each other in the first direction. It is arranged. Thus, resistance welding between the inclined portion and the focusing portion can be easily performed by arranging the two inclined portions to be apart from each other. As a result, it is possible to avoid an operation that causes a short circuit at the time of resistance welding, and it is possible to suppress the occurrence of a short circuit due to an operation of connecting the electrode body and the current collector.

  The present invention can be realized not only as a method of manufacturing such a storage element and as a storage element, but also as a method of manufacturing a current collector included in the storage element and as a current collector. be able to.

  According to the method of manufacturing a storage element in the present invention, it is possible to suppress the occurrence of a short circuit resulting from the connection operation between the electrode body and the current collector.

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. BRIEF DESCRIPTION OF THE DRAWINGS They are a perspective view and sectional drawing which show the structure of the positive electrode collector which concerns on embodiment. It is sectional drawing which shows the structure in the state in which the electrode body connection part of the positive electrode collector concerning embodiment is connected to the edge part of an electrode body. It is a perspective view which shows the structure of the positive electrode collector which concerns on the modification 1 of embodiment. It is a perspective view which shows the structure of the positive electrode collector which concerns on the modification 2 of embodiment. It is a perspective view which shows the structure of the positive electrode collector which concerns on the modification 3 of embodiment.

  Hereinafter, with reference to the drawings, an electric storage device according to an embodiment (and its modification) of the present invention and a method for manufacturing the same 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 axis direction of the electrode body or the opposing direction of the short side of the container is defined as the X-axis direction. Further, the opposing direction of the long side of the container, the lateral direction of the short side of the container, or the arranging direction of the leg portions (electrode assembly connecting portion) in one current collector 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 surface of the container, or the extending direction of the leg portion (electrode connection 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). In the following description, for example, the X-axis plus direction indicates the arrow direction of the X-axis, and the X-axis minus direction indicates the opposite direction to the X-axis plus direction. 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. FIG. 3 is an exploded perspective view showing each component by decomposing the storage element 10 according to the present embodiment. In FIG. 3, the container body 111 is omitted.

  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 type, A various thing 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). Then, the electrode body 400 includes two focusing portions 411 and an active material layer non-formation portion of the positive electrode plate stacked and bundled at an end portion 410 on the X axis positive direction side (hereinafter also referred to as the first direction side). It has 412. In addition, the electrode body 400 has two focusing portions (not shown) in which the active material layer non-forming portions of the negative electrode plate are stacked and bundled at an end portion 420 on the X axis negative direction side. 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 these for about 30 to 40 sheets, the thickness is almost uniform 1 Two focusing parts are formed. In the present embodiment, an oval shape is illustrated as a cross-sectional shape of the electrode body 400, but a circular shape, an elliptical shape, or the like may be used.

  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, the positive electrode terminal 200 is inserted into the through hole 110 a of the lid 110 and the opening 511 of the positive electrode current collector 500 by caulking, etc. It is fixed to the lid 110 together with the positive electrode current collector 500. The same applies to the negative electrode terminal 300.

  The positive electrode current collector 500 is a member that is disposed on the X axis positive direction side (first direction side) of the electrode body 400 and connected to the end portion 410 of the electrode body 400. Specifically, positive electrode current collector 500 is disposed between end portion 410 of electrode assembly 400 and the side wall of container main body 111, and is electrically connected to positive electrode terminal 200 and the positive electrode plate of electrode assembly 400. It is a member provided with conductivity and rigidity. In addition, the negative electrode current collector 600 is a member that is disposed on the side of the electrode assembly 400 in the negative X-axis direction and connected to the end 420 of the electrode assembly 400. Specifically, negative electrode current collector 600 is disposed between end 420 of electrode assembly 400 and the side wall of container main body 111, and is electrically connected to negative electrode terminal 300 and the negative electrode plate of electrode assembly 400. It is a member provided with conductivity and rigidity.

  More specifically, the positive electrode current collector 500 and the negative electrode current collector 600 are conductive plates disposed 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. Like members. 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 laminated electrode plates of the electrode assembly 400, that is, to the end portion 410 and the end portion 420 of the electrode assembly 400. There is. 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 Detailed Description of Configuration of Positive Electrode Current Collector 500]
Here, as shown in FIG. 3, the positive electrode current collector 500 has a terminal connection portion 510 and electrode body connection portions 520 and 530. Hereinafter, these configurations will be described in detail using FIGS. 4 and 5 as well. FIG. 4 is a perspective view and a cross-sectional view showing the configuration of the positive electrode current collector 500 according to the present embodiment. Specifically, (a) of FIG. 4 is a perspective view showing the configuration of the positive electrode current collector 500, and (b) of FIG. 4 is a configuration of the electrode body connection portions 520 and 530 of the positive electrode current collector 500. 4B is a cross-sectional view (a cross-sectional view taken along a line IVb-IVb in (a) of FIG. 4). FIG. 5 is a cross-sectional view showing the configuration of the positive electrode current collector 500 according to the present embodiment in a state in which the electrode body connection portions 520 and 530 are connected to the end portion 410 of the electrode body 400. In addition, since the positive electrode current collector 500 and the negative electrode current collector 600 have the same configuration, in the following, the configuration of the positive electrode current collector 500 will be described, and the configuration of the negative electrode current collector 600 will be described. Is omitted.

  As shown in these figures, the positive electrode current collector 500 includes a terminal connection portion 510, and electrode body connection portions 520 and 530 arranged side by side in the Y-axis direction on the side of the terminal connection portion 510 in the negative Z-axis direction. have. The terminal connection portion 510 is a base of the positive electrode current collector 500 disposed on the positive electrode terminal 200 side (upper side, Z-axis plus direction side) of the positive electrode current collector 500. Specifically, terminal connection portion 510 is a flat portion parallel to the XY plane in which circular opening portion 511 described above is formed, and is electrically and mechanically connected (joined) to positive electrode terminal 200. Ru.

  The electrode body connection portions 520 and 530 are leg portions of the positive electrode current collector 500 disposed on the electrode body 400 side (lower side, Z-axis negative direction side) of the positive electrode current collector 500. Specifically, the electrode connection parts 520 and 530 extend from the end of the terminal connection part 510 in the positive X-axis direction and in the positive Y-axis direction and the negative Y-axis side in the negative Z-axis direction. It is a long and flat part which is electrically and mechanically connected (joined) to the electrode body 400.

  That is, as shown in FIG. 5, the electrode body connection portions 520 and 530 are connected to the end portion 410 on the X axis positive direction side (first direction side) of the electrode body 400. Specifically, the electrode body connection portion 520 is disposed on the Y-axis plus direction side of the focusing portion 411 of the end portion 410 of the electrode body 400 and is joined to the focusing portion 411. In addition, the electrode body connection portion 530 is disposed on the Y axis negative direction side of the focusing portion 412 of the end portion 410 of the electrode body 400 and is joined to the focusing portion 412. Thus, the focusing portion 411 is a portion where the electrode plates are stacked in the normal direction of the contact surface with the electrode connection portion 520, and the focusing portion 412 is in the normal direction of the contact surface with the electrode connection portion 530. It becomes the part where the electrode plate was laminated. Note that a backing plate may be disposed on the negative Y-axis side of the focusing part 411 so as to sandwich the focusing part 411 with the electrode connection 520, or on the positive Y-axis side of the focusing part 412. A backing plate may be disposed so as to sandwich the focusing portion 412 with the electrode body connection portion 530.

[Detailed Description of Configuration of Electrode Body Connecting Sections 520 and 530]
Here, the configuration of the electrode body connection parts 520 and 530 will be described in detail. As shown in FIGS. 4 and 5, the electrode body connection portion 520 includes an inclined portion 521, a first extending portion 522, and a second extending portion 523. In addition, the electrode body connection portion 530 includes an inclined portion 531, a first extending portion 532 and a second extending portion 533. In addition, since the electrode connection part 520 and the electrode connection part 530 have a symmetrical shape in the Y-axis direction, in the following, the description will be made centering on the configuration of the electrode connection part 520. The description of the configuration of the connection unit 530 may be simplified or omitted.

  The inclined portion 521 is a portion on the first direction side (X-axis plus direction side) of the electrode body connection portion 520, and is disposed to be inclined with respect to the first direction. Specifically, the inclined portion 521 is a rectangular and flat portion extending in the Z-axis direction and disposed so as to be inclined toward the Y-axis plus direction toward the X-axis plus direction. For example, the inclined portion 521 is inclined at an angle of about 45 ° from the X-axis direction to the Y-axis plus direction side. Further, the inclined portion 531 is, like the inclined portion 521, a rectangular and flat portion extending in the Z-axis direction disposed to be inclined with respect to the first direction, but unlike the inclined portion 521, X It is disposed to be inclined in the negative direction of the Y axis toward the positive direction of the axis. For example, the inclined portion 531 is inclined at an angle of about 45 ° from the X-axis direction to the Y-axis negative direction side. In this manner, the two inclined portions 521 and 531 are arranged to be inclined from the first direction so as to be apart from each other in the first direction.

  Also, the two inclined portions 521 and 531 are disposed corresponding to the two focusing portions 411 and 412. Specifically, the inclined portion 521 is disposed on the Y-axis plus direction side of the focusing portion 411 and is joined to the focusing portion 411 by resistance welding. Thereby, the resistance welded portion 700 with the end portion 410 of the electrode body 400 is formed in the inclined portion 521. The resistance welding portion 700 is a welding portion formed by resistance welding of the inclined portion 521 and the focusing portion 411. In the present embodiment, in the X axis direction, the X axis plus a little more than the central position of the inclined portion 521. It is formed at a position close to the direction. The inclined portion 531 is disposed on the negative side of the focusing portion 412 in the Y-axis direction, and is joined to the focusing portion 412 by resistance welding. Thus, in the inclined portion 531, as in the case of the inclined portion 521, the resistance welded portion 700 with the end portion 410 of the electrode assembly 400 is formed.

  The position and shape of resistance welding portion 700 in the Z-axis direction are not particularly limited, but, for example, two locations of inclined portions 521 and 531 in the positive Z-axis direction and negative Z-axis direction, or the center in the Z-axis direction A circular or rectangular resistance welded portion 700 is formed at three locations including the positions.

  The first extending portion 522 is extended in a direction different from the inclining direction of the inclining portion 521 on the second direction side (X-axis minus direction side) opposite to the first direction of the inclining portion 521, and the electrode It is a site that is placed along the end 410 of the body 400. That is, the first extending portion 522 is a portion extended along the first direction. Specifically, the first extending portion 522 extends from the end of the inclined portion 521 in the negative X-axis direction along the converging portion 411 in the negative X-axis direction, in the Z-axis direction. It is a rectangular and flat part extending. Then, with such a configuration, a bent portion 524 is formed between the inclined portion 521 and the first extending portion 522. The bent portion 524 is a portion formed at the boundary between the inclined portion 521 and the first extending portion 522, in which the electrode body connecting portion 520 is bent or curved. In the present embodiment, the bent portion 524 has a convex portion formed on the negative side in the Y-axis direction and a concave portion formed on the positive side in the Y-axis direction. The first extension portion 532 also has the same configuration as that of the first extension portion 522, and thus the description thereof is omitted.

  The second extending portion 523 is a portion extending in a direction away from the end portion 410 of the electrode body 400 toward the second direction on the second direction side (X-axis negative direction side) of the first extending portion 522 It is. Specifically, the second extending portion 523 extends from the end of the first extending portion 522 in the negative X-axis direction along the converging portion 411 in the negative X-axis direction and the positive Y-axis direction. It is a rectangular and flat part extending in the Z-axis direction. That is, the second extending portion 523 is disposed so as to be inclined in the Y-axis plus direction side as going in the X-axis minus direction. Then, with such a configuration, the bending portion 525 is formed between the first extending portion 522 and the second extending portion 523. The bending portion 525 is a portion formed at the boundary between the first extending portion 522 and the second extending portion 523 and in which the electrode body connecting portion 520 is bent or curved. In the present embodiment, the bent portion 525 has a convex portion formed on the negative side in the Y axis direction and a concave portion formed on the positive side in the Y axis direction. The second extending portion 533 also has the same configuration as that of the second extending portion 523 and thus the description thereof is omitted.

  Further, as shown in FIG. 4, the length of the inclined portion 521 in the inclination direction (the length L1 in the figure) is the length in the extension direction of the first extending portion 522 (the length L2 in the figure) Too long. In the present embodiment, since the length in the extending direction of the first extending portion 522 and the length in the inclining direction of the second extending portion 533 are approximately the same length, the length in the inclining direction of the inclining portion 521 The length is longer than the length in the inclination direction of the second extending portion 533. Furthermore, the length in the inclination direction of the inclined portion 521 is longer than the sum of the length in the extending direction of the first extending portion 522 and the length in the inclination direction of the inclined portion 521. Further, with regard to the length in the X-axis direction, the length of the inclined portion 521 is the length of the first extending portion 522, the length of the second extending portion 523, the first extending portion 522, and the second The total length with the extending portion 523 is longer than any of the lengths. The same applies to the electrode body connecting portion 530 side.

  Further, as shown in FIG. 5, since the resistance welding portion 700 is formed on the inclined portion 521, the resistance welding portion 700 is provided on the first direction side (X-axis plus direction side) of the electrode body connection portion 520. Specifically, the center position of the resistance welding portion 700 is disposed on the first direction side of the center position of the portion where the electrode connection portion 520 and the end portion 410 of the electrode body 400 face each other. That is, the center position (center position P of the figure) of the resistance welding portion 700 is the center position (portion within the region R1 of the figure) of the electrode body connecting portion 520 facing the focusing portion 411 It is arranged on the first direction side of the position Q1). In the present embodiment, the central position P of the resistance welding portion 700 is the central position (the central position Q2 in the figure) of the portion (portion in the region R2 in the figure) where the inclined portion 521 and the first extending portion 522 are combined. ) Is disposed on the first direction side. Further, the center position P of the resistance welding portion 700 is disposed on the first direction side of the center position (center position Q3 of FIG. 6) of the inclined portion 521 (portion within the region R3 of FIG. The same applies to the electrode body connecting portion 530 side.

[4. Description of a method of manufacturing the storage element 10]
Next, a method of manufacturing the storage element 10 configured as described above will be described. Specifically, a resistance welding step of forming the resistance welding portion 700 by resistance welding of the electrode body connection portion 520 and the end portion 410 of the electrode body 400 will be described. The same applies to the electrode body connecting portion 530 side.

  That is, in the resistance welding step, the inclined portion 521 of the electrode connecting portion 520, which is disposed to be inclined with respect to the first direction, and the end portion 410 of the electrode body 400 are resistance-welded to each other. A resistance weld 700 is formed at 521. Specifically, the electrode connecting portion 520 is disposed on the side of the converging portion 411 in the positive Y-axis direction such that the inclined portion 521 is inclined with respect to the X-axis direction. And resistance welding part 700 is formed by resistance-welding inclined part 521 and focusing part 411.

  Further, in this resistance welding step, the center position of the resistance welding portion 700 is arranged on the first direction side of the center position of the portion where the electrode body connecting portion 520 and the end portion 410 of the electrode body 400 are opposed. As a result, a resistance weld 700 is formed. That is, the center position (center position P) of the resistance welding portion 700 is closer to the first direction than the center position (center position Q1) of the portion (portion in the region R1) of the electrode body connection portion 520 facing the focusing portion 411. To form a resistance weld 700.

[5 Description of effect]
As described above, according to the method of manufacturing power storage device 10 according to the embodiment of the present invention, resistance welding of inclined portion 521 of electrode body connection portion 520 of positive electrode current collector 500 and end portion 410 of electrode body 400 is performed. When forming the resistance welding portion 700, the center position of the resistance welding portion 700 is on the first direction side of the center position of the portion where the electrode body connection portion 520 and the end portion 410 of the electrode body 400 are opposed. Place on Here, the inclined portion 521 is a portion inclined with respect to the first direction of the electrode body connection portion 520 of the positive electrode current collector 500. For this reason, in the range of the same length in the first direction, it is possible to make the length longer by inclining the inclined portion 521 than arranging the inclined portion 521 in the first direction. The length of the end portion 410 of the opposing electrode body 400 can also be increased. Furthermore, the center position of the resistance welding portion 700 is disposed on the first direction side of the center position of the opposing portion of the electrode connection portion 520 and the end portion 410 of the electrode body 400, and the resistance welding portion 700 is Form away from the body 400. As described above, the resistance welded portion 700 is disposed away from the separator of the electrode assembly 400 while the length of the end portion 410 of the electrode assembly 400 is increased. Thus, the distance between the resistance welding portion 700 and the separator can be increased, so that heat from the resistance welding portion 700 can be used to suppress shrinkage of the separator and contact between the positive electrode plate and the negative electrode plate. . Therefore, the occurrence of a short circuit due to the connection operation between the electrode body 400 and the positive electrode current collector 500 can be suppressed.

  Further, according to power storage device 10 in accordance with the embodiment of the present invention, electrode body connection portion 520 of positive electrode current collector 500 is inclined with respect to the first direction, and resistance welding with end portion 410 of electrode body 400 is performed. It has the inclined part 521 in which the part 700 was formed. The center position of the resistance welding portion 700 is disposed on the first direction side of the center position of the portion where the electrode body connection portion 520 and the end portion 410 of the electrode body 400 face each other. As a result, as described above, the distance between the resistance welding portion 700 and the separator can be increased, so that the heat from the resistance welding portion 700 causes the separator to be shrunk to suppress contact between the positive electrode plate and the negative electrode plate. can do. Therefore, the occurrence of a short circuit due to the connection operation between the electrode body 400 and the positive electrode current collector 500 can be suppressed. Further, since the inclined portion 521 can be made longer than not inclined, the cross-sectional area of the positive electrode current collector 500 can be increased, and the resistance when current flows in the positive electrode current collector 500 can be obtained. It can be reduced.

  In addition, in the positive electrode current collector 500, the electrode body connection portion 520 has a direction different from the inclination direction of the inclined portion 521 on the second direction side (X-axis minus direction side) opposite to the first direction of the inclined portion 521. , And has a first extension 522 along the end 410 of the electrode assembly 400. As described above, the first extension portion 522 is extended in a direction different from the inclination direction of the inclined portion 521, whereby the electrode body connection portion 520 has a curved shape. Therefore, the length of the electrode body connection portion 520 can be made longer than that of forming the electrode body connection portion 520 in a linear shape, and the length of the end portion 410 of the electrode body 400 can also be made longer. Thus, the distance between the resistance welding portion 700 and the separator can be increased, so that heat from the resistance welding portion 700 can be used to suppress shrinkage of the separator and contact between the positive electrode plate and the negative electrode plate. . Therefore, the occurrence of a short circuit due to the connection operation between the electrode body 400 and the positive electrode current collector 500 can be suppressed.

  Moreover, the strength of the electrode body connection portion 520 can be improved by forming the electrode body connection portion 520 in a bent shape. Therefore, damage to the electrode assembly 400 due to damage to the electrode connection portion 520 can be suppressed. As a result, damage to the electrode assembly 400 and contact between the positive electrode plate and the negative electrode plate can be suppressed, so that the occurrence of a short circuit can be suppressed. In addition, since the cross-sectional area of the positive electrode current collector 500 can be increased by forming the electrode body connection portion 520 in a curved shape, the resistance when current flows in the positive electrode current collector 500 can be reduced.

  In addition, in the positive electrode current collector 500, the length in the inclination direction of the inclined portion 521 of the electrode body connection portion 520 is longer than the length in the extension direction of the first extending portion 522. Here, since the present application is configured to suppress shrinkage of the separator due to heat from the resistance welding portion 700, the area of the resistance welding portion 700 can be made large. Therefore, the length of the inclined portion 521 in the inclination direction can be lengthened to increase the area of the resistance weld portion 700, whereby the bonding area between the electrode body connection portion 520 and the end portion 410 of the electrode body 400 can be increased. It can be enlarged. Thus, the resistance between the electrode body connecting portion 520 and the end portion 410 of the electrode body 400 is reduced by increasing the bonding area between the electrode body connecting portion 520 and the end portion 410 of the electrode body 400, and the electrode The body connection portion 520 can be firmly fixed to the end portion 410 of the electrode body 400.

  In addition, in the positive electrode current collector 500, the first extension portion 522 of the electrode body connection portion 520 is extended along the first direction, whereby the electrode body connection portion 520 is obliquely applied to the electrode body 400. Damage to the electrode assembly 400 due to contact can be suppressed. Thereby, damage to the electrode body 400 and contact between the positive electrode plate and the negative electrode plate can be suppressed. Therefore, generation of a short circuit due to a connection operation between the electrode body 400 and the positive electrode current collector 500 It can be suppressed.

  In addition, in the positive electrode current collector 500, the electrode body connection portion 520 is a second extension portion 523 which is separated from the end portion 410 of the electrode body 400 as it goes in the second direction toward the second direction side of the first extension portion 522. have. Thus, the second extending portion 523 is extended in the direction away from the end portion 410 of the electrode body 400, and the electrode body connecting portion 520 is further bent, so that the electrode body connecting portion 520 is formed. Further, damage to the electrode body 400 due to contact with the electrode body 400 can be further suppressed. In addition, the second extending portion 523 functions as a cooling mechanism, and can release heat generated at the time of welding. As a result, the electrode body 400 can be further prevented from being damaged and the positive electrode plate and the negative electrode plate coming into contact with each other. Therefore, the occurrence of a short circuit due to the connection work between the electrode body 400 and the positive electrode current collector 500 Can be further suppressed.

  Moreover, the strength of the electrode body connection portion 520 can be further improved by the electrode body connection portion 520 being further bent. Therefore, damage to the electrode assembly 400 due to damage to the electrode connection portion 520 can be further suppressed. As a result, damage to the electrode assembly 400 and contact between the positive electrode plate and the negative electrode plate can be further suppressed, so that the occurrence of a short circuit can be further suppressed. Further, since the cross-sectional area of the positive electrode current collector 500 can be further increased by the electrode body connecting portion 520 being further bent, the resistance when current flows in the positive electrode current collector 500 is further reduced. Can.

  Further, the positive electrode current collector 500 has two inclined portions 521 and 531 corresponding to the two focusing portions 411 and 412 at the end portion 410 of the electrode body 400, and the two inclined portions 521 and 531 are It is arrange | positioned so that it may mutually be separated, as it goes to a 1st direction. Thus, resistance welding between the inclined portions 521 and 531 and the focusing portions 411 and 412 can be easily performed by arranging the two inclined portions 521 and 531 so as to be apart from each other. This makes it possible to avoid the operation of causing a short circuit at the time of resistance welding, and to suppress the occurrence of a short circuit resulting from the connection operation of the electrode assembly 400 and the positive electrode current collector 500.

  In addition, since the electrode body connection portion 530 side has the same configuration as the electrode body connection portion 520 side, the same effect can be obtained.

[Description of Modification of Sixth Embodiment]
(Modification 1)
Next, a first modification of the above embodiment will be described. FIG. 6 is a perspective view showing the configuration of a positive electrode current collector 500a according to Modification 1 of the present embodiment. In addition, the same figure is a figure corresponding to (a) of FIG.

  As shown in FIG. 6, the positive electrode current collector 500a in this modification has electrode body connection portions 520a and 530a in place of the electrode body connection portions 520 and 530 of the positive electrode current collector 500 in the above embodiment. ing. The electrode connection parts 520a and 530a have the inclined parts 521 and 531 and the first extending parts 522 and 532 in the above embodiment, but do not have the second extending parts 523 and 533. . The other configuration of this modification is the same as that of the above embodiment, and the detailed description will be omitted.

  As described above, according to the storage element of the present modification, the same effects as the above embodiment (except the effects related to the second extending portions 523 and 533) can be obtained. In particular, in the present modification, since the second extending portions 523 and 533 in the above embodiment are not provided, the positive electrode current collector 500a can be easily manufactured. The same modification can be applied to the electrode body connection portion 530 side.

(Modification 2)
Next, a second modification of the above embodiment will be described. FIG. 7 is a perspective view showing a configuration of a positive electrode current collector 500b according to Modification 2 of the present embodiment. In addition, the same figure is a figure corresponding to (a) of FIG.

  As shown in FIG. 7, the positive electrode current collector 500b in this modification has electrode body connection portions 520b and 530b in place of the electrode body connection portions 520 and 530 of the positive electrode current collector 500 in the above embodiment. ing. The electrode connection parts 520b and 530b have inclined parts 521b and 531b corresponding to the inclined parts 521 and 531 in the above embodiment, but the first extending parts 522 and 532 and the second extending parts 523 and It does not have 533. The other configuration of this modification is the same as that of the above embodiment, and the detailed description will be omitted.

  As described above, according to the storage element of the present modification, the same effects (excluding the effects relating to the first extending portions 522 and 532 and the second extending portions 523 and 533) to the above embodiment can be obtained. Can play. In particular, in the present modification, since the first extending portions 522 and 532 and the second extending portions 523 and 533 in the above-described embodiment are not provided, the positive electrode current collector 500 b can be manufactured more easily. . The same modification can be applied to the electrode body connection portion 530 side.

(Modification 3)
Next, a third modification of the above embodiment will be described. FIG. 8 is a perspective view showing the configuration of a positive electrode current collector 500c according to the third modification of the present embodiment. In addition, the same figure is a figure corresponding to (a) of FIG.

  As shown in FIG. 8, a positive electrode current collector 500c in this modification has electrode body connection portions 520c and 530c instead of the electrode body connection portions 520 and 530 of the positive electrode current collector 500 in the above embodiment. ing. The electrode connection parts 520c and 530c have the inclined parts 521c and 531c corresponding to the inclined parts 521 and 531 in the above embodiment, as in the second modification. And the second extending portions 523 and 533 are not provided. The other configuration of this modification is the same as that of the above embodiment, and the detailed description will be omitted.

  In this modification, the inclined portions 521c and 531c have a shape that is twisted around the Z axis. That is, although the end portions on the Z-axis positive direction side are directed to the first direction (X-axis positive direction), the inclined portions 521c and 531c are gradually inclined with respect to the first direction as going to the Z-axis negative direction It is shaped to Specifically, the inclined portions 521c and 531c have a shape in which they are gradually inclined from the first direction such that the end portions on the X-axis plus direction side gradually separate in the negative Z-axis direction. ing.

  As described above, according to the storage element of the present modification, the same effects as the modification 2 can be obtained. In particular, in the present modification, the inclined portions 521c and 531c can be formed by twisting the electrode body connecting portions 520c and 530c, so that the positive electrode current collector 500c can be easily manufactured. The same modification can be applied to the electrode body connection portion 530 side.

(Other modifications)
As mentioned above, although the electrical storage element 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-described embodiment and the modification thereof, the length in the inclination direction of the inclined portion 521 is longer than the length in the extension direction of the first extending portion 522. However, the length of the inclined portion 521 in the inclination direction may be equal to or less than the length of the first extending portion 522 in the extending direction. Further, although the length of the inclined portion 521 in the inclination direction is longer than the length of the second extending portion 523 in the extending direction, the length may be equal to or less than the length.

  Further, in the above-described embodiment and its modification, the first extending portion 522 is extended along the first direction. However, the first extending portion 522 may extend at an angle with respect to the first direction. For example, the first extending portion 522 may be inclined and extended in the same direction as the inclining direction of the second extending portion 523 (a direction different from the inclining direction of the inclining portion 521). Further, the first extending portion 522 may be extended at an inclination angle smaller than that of the inclined portion 521 and inclined in the same direction as the inclination direction of the inclined portion 521.

  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, but a stack type in which flat plate-like electrode plates are stacked, or a shape in which electrode plates and / or separators are folded in a bellows shape (a separator is twisted to make a rectangular electrode plate It may be a form in which it is sandwiched, a form in which the electrode plate and the separator are stacked, and a form in which the sheet is folded.

  Further, in the above-described embodiment and its modification, positive electrode current collector 500 and electrode assembly 400 are joined only by resistance welding, but in addition to resistance welding, other joining methods such as caulking Bonding may be performed. The bonding strength can be improved and the contact resistance can be reduced by performing bonding by another bonding method.

  Further, in the above-described embodiment and the modification thereof, both of the electrode body connecting portions 520 and 530 of the positive electrode current collector 500 have the above-described configuration, either of the electrode body connecting portions 520 and 530 Only one or the other may have the above configuration.

  Further, in the above embodiment and its modification, although both of the positive electrode current collector 500 and the negative electrode current collector 600 have the above configuration, the positive electrode current collector 500 and the negative electrode current collector 600 Only one of them may have the above configuration.

  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.

  Furthermore, the present invention can be realized not only as a method of manufacturing such a storage element and as a storage element, but also as a method of manufacturing a current collector included in the storage element and as a current collector. be able to.

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

DESCRIPTION OF SYMBOLS 10 Storage element 100 Container 110 Lid 110a Through-hole 111 Container main body 200 Positive electrode terminal 210 Projected part 300 Negative electrode terminal 400 Electrode body 410, 420 End part 411, 412 Focusing part 500, 500a, 500b, 500c Positive electrode current collector 510 Terminal connection Portions 511 Openings 520, 520a, 520b, 520c, 530 Electrode body connection portions 521, 521b, 521c, 531 Slanted portions 522, 532 First extending portions 523, 533 Second extending portions 524, 525 Bent portions 600 Negative electrode collection Current collector 700 resistance weld

Claims (7)

A method of manufacturing a power storage device, comprising: an electrode body; and a current collector having an electrode body connection portion connected to an end of the electrode body on the first direction side,
The resistance welding which forms a resistance welding part in the said inclination part by resistance-welding the inclination part arrange | positioned with respect to the said 1st direction of the said electrode body connection parts, and the edge part of the said electrode body Including the process,
In the resistance welding step, the center position of the resistance welding portion is disposed on the first direction side relative to the center position of a portion where the electrode body connecting portion and the end portion of the electrode body are opposed to each other. Forming the resistance weld,
Method of manufacturing a storage element. An electrode body, and a current collector disposed on the first direction side of the electrode body,
The current collector has an electrode body connection portion connected to an end portion of the electrode body,
The electrode body connection portion has an inclined portion which is disposed to be inclined with respect to the first direction and in which a resistance welded portion with an end portion of the electrode body is formed.
The center position of the resistance welding portion is disposed on the first direction side with respect to the center position of a portion where the electrode body connecting portion and the end portion of the electrode body are opposed to each other.
Storage element. The electrode body connection portion further includes
A first extension extending in a direction different from the inclining direction of the inclining portion on a second direction side opposite to the first direction of the inclining portion and disposed along an end of the electrode body With equipment
The storage element according to claim 2. The length of the inclined portion in the inclination direction is longer than the length of the first extending portion in the extending direction,
The storage element according to claim 3. The first extending portion is extended along the first direction.
The storage element according to claim 3 or 4. The electrode body connection portion further includes
The second extending portion is provided on the second direction side of the first extending portion, the second extending portion extending in a direction away from the end of the electrode body toward the second direction.
The electrical storage element of any one of Claims 3-5. The end of the electrode body has two focusing parts in which a plurality of electrode plates are stacked,
The current collector has two of the inclined portions corresponding to the two focusing portions,
The two inclined portions are arranged to be inclined from the first direction so as to be apart from each other as going in the first direction.
The electrical storage element of any one of Claims 2-6.

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