JP2019179734A - Power storage element and manufacturing method for power storage element - Google Patents

Abstract

To provide a power storage element capable of keeping flatness of a conductive member such as a collector.SOLUTION: A power storage element 10 comprises: a container 100 having a first open hole 120a; a lower gasket 400 (insulation member) having a second open hole 410a communicating with the first open hole 120a, the lower gasket facing the container 100; a collector 500 (first conductive member) having a third open hole 510a communicating with the first open hole 120a and the second open hole 410a, the collector holding the lower gasket 400 together with the container 100; and an electrode terminal 200 (second conductive member) having a caulking part 210 caulked in a state of being inserted into the first open hole 120a, the second open hole 410a, and the third open hole 510a, the caulking part 210 being in contact with the collector 500. Around the second open hole 410a on the lower gasket 400 is provided an annular salient 411 protruding toward the collector 500 before the caulking part is caulked.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a power storage element including an insulating member disposed between a container and a current collector, and a method for manufacturing the power storage element.

  2. Description of the Related Art Conventionally, a power storage device including a container, an electrode terminal, a current collector, and an insulating member is widely known. For example, Patent Document 1 discloses a power storage device including a container, an electrode terminal, a current collector electrically connected to the electrode terminal, and an insulating member disposed between the container and the current collector. Has been. And these are assembled | attached by the electrode terminal being crimped in the state which penetrated the container, the insulating member, and the electrical power collector.

JP 2013-93160 A

  By the way, in the assembly by caulking, since a larger force is applied around the electrode terminal in the insulating member than in other regions, the amount of compression is also large. As a result, the current collector overlapping the insulating member is also warped due to the deformation of the insulating member.

  An object of this invention is to provide the electrical storage element which can maintain the flatness of electrically conductive members, such as a collector.

  To achieve the above object, a power storage device according to one embodiment of the present invention includes a container having a first through hole, an insulating member having a second through hole communicating with the first through hole, and facing the container. A first through hole having a third through hole communicating with the first through hole and the second through hole, sandwiching the insulating member together with the container, and inserted into the first through hole, the second through hole, and the third through hole. And a second conductive member that is in contact with the first conductive member, and the first through member in the insulating member has a first crimped portion around the second through-hole before the crimped portion. An annular convex portion protruding toward the conductive member is provided.

  According to this, since the periphery of the second through hole in the insulating member is a convex portion protruding toward the first conductive member, even if the convex portion is compressed by caulking, the flatness with other regions is maintained. can do. Therefore, the deformation of the first conductive member due to the deformation of the insulating member is suppressed, and the flatness of the first conductive member can be maintained.

  Moreover, the convex part has overlapped with the crimping | crimped part in the axial direction view of the 2nd through-hole.

  According to this, since the convex part overlaps with the crimping part, the part where the pressure is applied most during caulking, that is, the part that is compressed most can be the convex part. Thereby, the flatness of the convex part after compression and another area | region can be maintained reliably.

  Moreover, the convex part is extended to the outward of the crimping | crimped part in the axial view of the 2nd through-hole.

  According to this, since the convex portion extends to the outside of the caulking portion, the portion to which the pressure is applied most during caulking, that is, the portion that is most compressed can be received by the entire convex portion. Thereby, the flatness of the convex part after compression and other area | regions can be maintained more reliably.

  Further, the surface of the convex portion on the second through hole side and the inner peripheral surface forming the second through hole are flush with each other.

  According to this, since the surface on the second through hole side of the convex portion and the inner peripheral surface forming the second through hole are flush with each other, when the convex portion is compressed by caulking, the convex portion is It tends to be closer to the two through holes. Therefore, the convex part after compressive deformation comes into close contact with a member (such as a shaft part of the second conductive member or another insulating member) in the second through hole, and can improve insulation and airtightness. .

  Moreover, the outer peripheral surface in a convex part is a taper surface which becomes thin toward the front-end | tip.

  According to this, since the outer peripheral surface of the convex portion is a tapered surface that narrows toward the tip, when the convex portion is compressed by caulking, the convex portion is likely to move closer to the second through hole side. Therefore, the convex part after compressive deformation comes into close contact with a member (such as a shaft part of the second conductive member or another insulating member) in the second through hole, and can improve insulation and airtightness. .

  The first conductive member is one of the current collector and the electrode terminal, and the second conductive member is the other.

  According to this, when the first conductive member is a current collector and the second conductive member is an electrode terminal, the crimped portion is provided on the electrode terminal. For this reason, the caulking part is located inside the container. That is, in a power storage element that employs a so-called inner caulking structure, deformation of the current collector due to deformation of the insulating member can be suppressed.

  On the other hand, when the first conductive member is an electrode terminal and the second conductive member is a current collector, a crimping portion is provided on the current collector. For this reason, the caulking part is located outside the container. In other words, in the energy storage device in which a so-called outer caulking structure is adopted, deformation of the electrode terminal due to deformation of the insulating member can be suppressed.

  In addition, a method for manufacturing a power storage element according to one embodiment of the present invention includes a container having a first through hole, an insulating member having a second through hole and an annular protrusion provided around the second through hole. When the first conductive member having the third through hole is overlapped in the order, the first through hole, the second through hole, and the third through hole are placed with the convex portion facing the first conductive member. The first conductive member is connected to the first conductive member by caulking the caulking portion after the shaft-like caulking portion of the second conductive member is inserted into the first through hole, the second through hole, and the third through hole. The convex part is compressed via

  According to this, since the periphery of the second through hole in the insulating member is a convex portion protruding toward the first conductive member, even if the convex portion is compressed by caulking, the flatness with other regions is maintained. can do. Therefore, the deformation of the first conductive member due to the deformation of the insulating member can be suppressed.

  According to the electricity storage device of the present invention, the flatness of a conductive member such as a current collector can be maintained.

It is a perspective view which shows the external appearance of the electrical storage element which concerns on embodiment. It is a disassembled perspective view which decomposes | disassembles the electrical storage element which concerns on embodiment, and shows each component. It is a perspective view which shows the structure of the electrical power collector which concerns on embodiment. It is a perspective view which shows the structure of the lower gasket which concerns on embodiment. It is sectional drawing which shows the structure in the state which attached the lower gasket, upper gasket, collector, and electrode terminal which concern on embodiment to the cover body. FIG. 6 is a cross-sectional view showing a state before the current collector is assembled to the electrode terminal of FIG. 5. It is the graph which compared the contact force with respect to the electrical power collector produced by compressively deforming the lower gasket which concerns on embodiment, and the lower gasket of a comparative example by crimping. It is sectional drawing which shows the structure of the lower gasket which concerns on the modification 1 of embodiment. It is sectional drawing which shows the structure of the lower gasket which concerns on the modification 2 of embodiment. It is sectional drawing which shows the structure of the lower gasket which concerns on the modification 3 of embodiment. It is sectional drawing which shows the structure of the lower gasket which concerns on the modification 4 of embodiment. It is sectional drawing which shows the structure of the electrode terminal which concerns on the modification 5 of embodiment, an upper gasket, a lower gasket, and a collector.

  Hereinafter, a power storage device according to an embodiment of the present invention (and a modification thereof) will be described with reference to the drawings. It should be noted that each of the embodiments described below shows a comprehensive or specific example. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, manufacturing steps, order of manufacturing steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements. In each drawing, dimensions and the like are not strictly illustrated.

  In the following description and drawings, a pair of electrode terminals (positive electrode and negative electrode, the same applies hereinafter) of the power storage element, a pair of current collectors, a pair of upper gaskets, and a pair of lower parts The X-axis direction is defined as the direction in which the gaskets are aligned, the direction in which both ends of the electrode body (the pair of active material layer non-forming portions), the winding axis direction of the electrode body, or the short side surface of the container is opposed. Also, the opposing direction of the long side surface of the container, the short side direction of the short side surface of the container, the thickness direction of the container, or the arrangement direction of the legs (electrode body connecting portions) in one current collector is defined as the Y-axis direction. To do. Further, the direction in which the container body and the lid of the electricity storage element are arranged, the longitudinal direction of the short side surface of the container, or the extending direction of the legs of the current collector (electrode body connection part) is defined as the Z-axis direction. These X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect (orthogonal in this 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 direction opposite to the X-axis plus direction. The same applies to the Y-axis direction and the Z-axis direction.

(Embodiment)
[1 General Description of Power Storage Element 10]
First, a general description of the power storage element 10 in the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing an external appearance of a power storage element 10 according to the present embodiment. FIG. 2 is an exploded perspective view showing each component by disassembling the power storage device 10 according to the present embodiment.

  The storage element 10 is a secondary battery that can charge electricity and discharge electricity, and specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The power storage element 10 is used, for example, for an automobile power source such as an electric vehicle (EV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV), an electronic device power source, and a power storage power source. In addition, the electric storage element 10 may be mounted as a starting battery for an engine in a vehicle such as a gasoline vehicle or a diesel vehicle. In addition, the electrical storage element 10 is not limited to a nonaqueous electrolyte secondary battery, A secondary battery other than a nonaqueous electrolyte secondary battery may be sufficient, and a capacitor may be sufficient as it. Moreover, the electrical storage element 10 may be not a secondary battery but a primary battery that can use stored electricity without being charged by a user. Further, the power storage element 10 may be a battery using a solid electrolyte. Further, in the present embodiment, a rectangular parallelepiped (rectangular) power storage element 10 is illustrated, but the shape of the power storage element 10 is not limited to a rectangular parallelepiped shape, and is other than a cylindrical shape, a long cylindrical shape, or a rectangular parallelepiped shape. The shape may be a polygonal column or the like, or a laminate-type power storage element can be used.

  As shown in FIG. 1, the power storage device 10 includes a container 100, positive and negative electrode terminals 200, and positive and negative upper gaskets 300. Further, as shown in FIG. 2, the lower gasket 400 for the positive and negative electrodes, the current collector 500 for the positive and negative electrodes, and the electrode body 600 are accommodated inside the container 100. In addition, although the electrolyte solution (nonaqueous electrolyte) is enclosed in the inside of the container 100, illustration is abbreviate | omitted. There are no particular restrictions on the type of the electrolytic solution as long as it does not impair the performance of the electricity storage device 10, and various types can be selected. In addition to the above components, a spacer disposed on the side of the positive and negative current collectors 500, an insulating film that wraps the electrode body 600, and the like may be disposed.

  The container 100 includes a container body 110 having a rectangular cylindrical shape and a bottom, and a lid body 120 that is a plate-like member that closes the opening of the container body 110. In addition, the container 100 can be hermetically sealed by welding the container body 110 and the lid body 120 after the electrode body 600 and the like are accommodated therein. In addition, the material of the container main body 110 and the lid 120 is not particularly limited, and for example, a weldable metal such as stainless steel, aluminum, or an aluminum alloy can be used, but a resin can also be used. Further, the lid 120 has a gas discharge valve 125 that releases the pressure when the pressure inside the container 100 rises, and a liquid injection unit (not shown) for injecting the electrolyte into the container 100. Etc.) are also provided.

  The electrode body 600 is a power storage element (power generation element) that includes a positive electrode plate, a negative electrode plate, and a separator and can store 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 that is a long strip-shaped current collector foil made of aluminum, an aluminum alloy, or the like. The negative electrode plate is an electrode plate in which a negative electrode active material layer is formed on a negative electrode base material layer that is a long strip-shaped current collector foil made of copper, a copper alloy, or the like. Note that as the current collector foil, a known material such as nickel, iron, stainless steel, titanium, baked carbon, a conductive polymer, conductive glass, or an Al—Cd alloy can be used as appropriate. Moreover, as a positive electrode active material and a negative electrode active material used for a positive electrode active material layer and a negative electrode active material layer, if it is an active material which can occlude-release lithium ion, a well-known material can be used suitably. Moreover, the separator can use the microporous sheet | seat which consists of resin, for example, and a nonwoven fabric.

  The electrode body 600 is formed by arranging and winding a separator between a positive electrode plate and a negative electrode plate. Specifically, in the electrode body 600, a positive electrode plate and a negative electrode plate are wound while being shifted from each other in the direction of a winding axis (in this embodiment, a virtual axis parallel to the X-axis direction) via a separator. ing. The positive electrode plate and the negative electrode plate have portions where the active material is not coated (the active material layer is not formed) and the base material layer is exposed (the active material layer non-formed portion) at the end portions in the respective shifted directions. )have. That is, the electrode body 600 has a positive electrode focusing portion in which the active material layer non-formation portion of the positive electrode plate is laminated and bundled at one end portion 610, and the active material layer of the negative electrode plate at the other end portion 610. The non-forming part is laminated and bundled with a negative electrode focusing part. In the present embodiment, an oval shape is illustrated as a cross-sectional shape of the electrode body 600, but the cross-sectional shape of the electrode body 600 may be a circular shape or an elliptical shape.

  The electrode terminal 200 is a terminal (positive electrode terminal and negative electrode terminal) that is electrically connected to the positive electrode plate and the negative electrode plate of the electrode body 600 through the current collector 500. That is, the electrode terminal 200 leads the electricity stored in the electrode body 600 to the external space of the electricity storage element 10 and introduces electricity into the internal space of the electricity storage element 10 in order to store electricity in the electrode body 600. This is a metal member. Further, the electrode terminal 200 is attached to a lid body 120 disposed above the electrode body 600.

  Specifically, as shown in FIG. 2, a caulking portion 210 protrudes downward from the lower surface of the electrode terminal 200. The caulking portion 210 has a cylindrical shape before caulking, and after the caulking, the tip portion 212 (see FIG. 5) is crushed so as to spread in a circular shape. The caulking portion 210 is inserted into the through hole 300a of the upper gasket 300, the first through hole 120a of the lid 120, the second through hole 410a of the lower gasket 400, and the third through hole 510a of the current collector 500. By being caulked, the current collector 500 and the lid 120 are fixed. In the present embodiment, the electrode terminal 200 is an example of a second conductive member. The electrode terminal 200 is made of aluminum, an aluminum alloy, copper, a copper alloy, or the like.

  The current collector 500 is a member (a positive electrode current collector and a negative electrode current collector) disposed on both sides in the X-axis direction of the electrode body 600 and connected to the end 610 of the electrode body 600. The current collector 500 is an example of a first conductive member that sandwiches the lower gasket 400 together with the lid 120 in the present embodiment. Specifically, the current collector 500 is disposed between the end 610 of the electrode body 600 and the side wall of the container body 110, and the positive and negative focusing portions of the end 610 of the electrode body 600 and the electrode terminal 200. And a member having electrical conductivity and rigidity. Further, the current collector 500 is fixedly connected (joined) to the lid 120 and the end portion 610 of the electrode body 600. With this configuration, the electrode body 600 is separated from the lid 120 by the current collector 500. It is held (supported) in a suspended state, and shaking due to vibration or impact is suppressed. The material of the current collector 500 is not limited. For example, the current collector 500 on the positive electrode side is formed of aluminum or an aluminum alloy as in the case of the positive electrode base material layer of the electrode body 600, and the current collector on the negative electrode side. 500 is formed of copper, a copper alloy, or the like, similarly to the negative electrode base material layer of the electrode body 600.

  The current collector 500 includes a terminal connection portion 510 and two electrode body connection portions 520 arranged side by side in the Y-axis direction on the negative side of the terminal connection portion 510 in the Z-axis direction. The terminal connection portion 510 is a base portion of the current collector 500 disposed on the electrode terminal 200 side (upper side, Z-axis direction plus side) of the current collector 500. The terminal connection portion 510 is a rectangular and flat portion parallel to the XY plane. The terminal connection portion 510 includes the above-described third through hole 510a.

  The electrode body connection portion 520 is a leg portion of the current collector 500 that is disposed on the electrode body 600 side (lower side, the Z-axis direction negative side) of the current collector 500. Specifically, the electrode body connecting portion 520 is a long and flat plate extending from one end portion of the terminal connecting portion 510 in the X-axis direction and from both ends of the Y-axis direction toward the negative side in the Z-axis direction. Which is electrically and mechanically connected (joined) to the end portion 610 of the electrode body 600.

  The upper gasket 300 is disposed between the lid body 120 and the electrode terminal 200 of the container 100, and insulates and seals between the lid body 120 and the electrode terminal 200 (positive upper gasket and negative upper gasket). It is. Specifically, the upper gasket 300 has a shape in which a through hole 300a into which the caulking portion 210 of the electrode terminal 200 is inserted is formed in the central portion of a substantially rectangular plate-shaped member. The upper gasket 300 is fixed to the lid 120 by inserting and crimping the crimping portion 210. The upper gasket 300 is made of, for example, polypropylene (PP), polyethylene (PE), polyphenylene sulfide resin (PPS), polyether ether ketone (PEEK), tetrafluoroethylene / perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene. (PTFE), polybutylene terephthalate (PBT), poly ether sulfone (PES) and other resins.

  The lower gasket 400 is a member (a positive electrode lower gasket and a negative electrode lower gasket) that is disposed between the lid 120 and the current collector 500 of the container 100 and insulates between the lid 120 and the current collector 500. The lower gasket 400 is an example of an insulating member. Specifically, the lower gasket 400 has a shape in which a second through-hole 410a into which the caulking portion 210 of the electrode terminal 200 is inserted is formed at a substantially central portion of a substantially rectangular plate-shaped member. The lower gasket 400 is fixed to the lid 120 by inserting and crimping the caulking portion 210 into the second through hole 410a. The lower gasket 400 is made of, for example, a resin such as PP, PE, PPS, PEEK, PFA, PTFE, PBT, or PES. A detailed description of the configuration of the lower gasket 400 will be described later.

[2 Detailed Description of Configuration of Lower Gasket 400 and Surrounding Members]
Next, the structure of the lower gasket 400 and its surrounding members will be described in detail. FIG. 3 is a perspective view showing the configuration of the lower gasket 400 according to the present embodiment. FIG. 4 is a perspective view showing the configuration of the lower gasket 400 according to the present embodiment. 4 is a perspective view of the lower gasket 400 viewed from a direction different from that in FIG. FIG. 5 is a cross-sectional view showing a configuration in which the lower gasket 400, the upper gasket 300, the current collector 500, and the electrode terminal 200 according to the present embodiment are attached to the lid 120. 5 is a cross-sectional view of a cut surface including a VV line in FIG. 6 is a cross-sectional view showing a state before the current collector 500 is assembled to the electrode terminal 200 of FIG. Here, the lower gasket 400 on the negative electrode side is described as an example, but the same applies to the positive electrode side.

  As shown in FIGS. 3 to 6, the lower gasket 400 includes a top plate portion 410 and a wall portion 420. The top plate part 410 is a rectangular and flat part parallel to the XY plane. The top plate portion 410 is formed with the circular second through-hole 410a described above. As shown in FIGS. 3 and 5, the upper surface (the surface on the plus side in the Z-axis direction) of the top plate portion 410 is continuous along the entire circumference of the second through-hole 410a, for example, an annular recess 412 in plan view. Is formed. As shown in FIGS. 5 and 6, a part of the lid 120 is accommodated in the recess 412. Specifically, on the lower surface of the lid 120 (the surface that comes into contact with the lower gasket 400), for example, a projection 121 having an annular shape in plan view that is continuous along the entire circumference of the first through hole 120a is formed. The protrusion 121 is accommodated in a state of being fitted in the recess 412 of the lower gasket 400. In addition, a concave portion 122 is provided at a position corresponding to the protruding portion 121 on the upper surface of the lid 120 (the surface that contacts the upper gasket 300). The recess 122 is formed in, for example, an annular shape in plan view, which is continuous along the entire circumference of the first through hole 120a.

  A part of the upper gasket 300 is accommodated in the recess 122 of the lid 120. Specifically, on the lower surface of the upper gasket 300 (the surface that comes into contact with the lid body 120), for example, an annular protruding portion 301 that is continuous along the entire circumference of the through-hole 300a is formed. The protruding portion 301 is accommodated in a state where the protruding portion 301 is fitted in the concave portion 122 of the lid 120. A recess 302 is provided on the upper surface of the upper gasket 300 (the surface in contact with the electrode terminal 200) at a position corresponding to the protrusion 301. The recess 302 is formed in, for example, an annular shape in plan view, which is continuous along the entire circumference of the through hole 300a.

  A cylindrical portion 305 that protrudes downward from the protrusion 301 is formed at the periphery of the through hole 300 a of the upper gasket 300. The cylindrical portion 305 passes through the first through hole 120 a of the lid 120 and the second through hole 410 a of the lower gasket 400. The tip of the cylindrical portion 305 is in contact with the upper surface of the terminal connection portion 510 of the current collector 500. In this state, the through hole 300a of the cylindrical portion 305 and the third through hole 510a of the current collector 500 are coaxially connected.

  A part of the electrode terminal 200 is accommodated in the recess 302 of the upper gasket 300. Specifically, on the lower surface of the electrode terminal 200 (the surface that comes into contact with the upper gasket 300), for example, an annular protruding portion 211 that is continuous along the entire circumference of the caulking portion 210 is formed. The protruding portion 211 is accommodated in a state in which the protruding portion 211 is fitted in the concave portion 302 of the upper gasket 300. The caulking portion 210 of the electrode terminal 200 is caulked at the tip end portion 212 of the caulking portion 210 in a state where the caulking portion 210 passes through the through hole 300 a of the upper gasket 300 and the third through hole 510 a of the current collector 500.

  As shown in FIGS. 4 to 6, the bottom surface (surface on the negative side in the Z-axis direction) of the top plate portion 410 is disposed to face the terminal connection portion 510 of the current collector 500, and the top surface of the terminal connection portion 510. Abut. As shown in FIGS. 4 and 6, a convex portion 411 is provided around the second through hole 410 a on the lower surface of the top plate portion 410. The convex portion 411 is compressed and deformed by the caulking portion 210 being caulked (see FIG. 5). The convex portion 411 is an annular convex portion that is continuous over the entire circumference of the second through-hole 410a in a state before compression deformation (before crimping). The surface 411b on the second through hole 410a side of the convex portion 411 is flush with the inner peripheral surface 410b forming the second through hole 410a. A surface 411 b on the second through hole 410 a side in the convex portion 411 is an inner peripheral surface of the convex portion 411.

  Moreover, the outer peripheral surface 413 in the convex part 411 is a taper surface which becomes thin toward the front-end | tip. Moreover, the front end surface 411a of the convex part 411 is formed in a plane. Specifically, the tip surface 411a is a plane parallel to the XY plane. That is, the front end surface 411 a is a plane parallel to the top plate portion 410 and the terminal connection portion 510 of the current collector 500.

  The wall portion 420 is provided over the entire circumference of the lower surface of the top plate portion 410 (the surface on the negative side in the Z-axis direction), and is erected downward from the lower surface of the top plate portion 410. A rectangular notch 421 is provided at one end of the wall 420 in the X-axis direction (in this embodiment, the end on the plus side in the X-axis direction). In addition, the other end portion of the wall 420 in the X-axis direction (in the present embodiment, the end portion on the minus side in the X-axis direction) is inclined so as to become lower toward the outside (minus side in the X-axis direction). Is provided. Note that the positional relationship between the notch portion 421 and the inclined portion 422 is reversed in the lower gasket 400 on the positive electrode side.

  As shown in FIG. 6, in a state before the current collector 500 is assembled to the electrode terminal 200, the crimping portion 210 of the electrode terminal 200 is not crimped, and has a cylindrical shape as a whole. Further, the convex portion 411 of the lower gasket 400 is not compressed and deformed.

  Thereafter, as shown in FIG. 5, the caulking portion 210 of the electrode terminal 200 is caulked after being inserted into the third through hole 510 a of the current collector 500, so that the lower gasket 400, the upper gasket 300, the current collector 500 and The electrode terminal 200 is assembled to the lid 120. After caulking, the tip 212 of the caulking portion 210 extends in a circular shape when viewed in the Z-axis direction. By this caulking, the convex portion 411 of the lower gasket 400 is compressed and deformed, and the tip end surface 411 a of the convex portion 411 is substantially flush with the lower surface of the top plate portion 410.

  Here, during caulking, a large pressure acts on the portion of the caulking portion 210 that faces the tip portion 212. For this reason, in the lower gasket 400, a larger pressure acts on the periphery of the second through hole 410a than in other regions (the lower surface of the top plate portion 410). However, a convex portion 411 is provided around the second through-hole 410a in the lower gasket 400, and the convex portion 411 is compressed and deformed larger than other regions by applying a large pressure to the convex portion 411. Is done. Thereby, after crimping, the convex part 411 compressed and deformed and the other area are substantially flush with each other. In the lower gasket 400, if the lower surface of the top plate portion 410 and the convex portion 411 are substantially flush with each other, it becomes difficult to deform the current collector 500 directly below the lower gasket 400. The convex portion 411 that is substantially flush with the lower surface of the top plate portion 410 after the caulking is restored to some extent to recover the convex shape when it is removed from the electrode terminal 200 by disassembly.

  FIG. 7 is a graph comparing the contact force with respect to the current collector produced by compressing and deforming the lower gasket 400 according to the present embodiment and the lower gasket of the comparative example by caulking.

  Here, the comparative example is a lower gasket obtained by removing the convex portion 411 from the lower gasket 400 according to the present embodiment. The contact force is a force that tends to warp the current collector 500. The crushing amount is a forced displacement amount with respect to the lower gasket caused by caulking. As shown in FIG. 7, it can be seen that the lower gasket 400 having the convex portion 411 has a smaller contact force than the lower gasket having no convex portion 411. That is, the lower gasket 400 according to the present embodiment can suppress deformation of the current collector 500 due to caulking.

  In FIG. 5, the convex part 411 before compressive deformation is shown by a broken line. The convex portion 411 overlaps the tip end portion 212 of the caulking portion 210 when viewed in the Z-axis direction. A convex portion 411 is a portion to which pressure is most applied during caulking, that is, a portion to be compressed most.

  Note that the front end 212 of the caulking portion 210 remains cylindrical before caulking, and thus the convex portion 411 does not overlap the front end 212 of the caulking portion 210 when viewed in the Z-axis direction. For this reason, the convex part 411 is previously formed so that it may overlap with the virtual front-end | tip part 212 formed after crimping by Z-axis direction view. The shape of the tip 212 after crimping can be obtained by various simulations and experiments. For this reason, the convex part 411 can be formed in the position which overlaps with respect to the front-end | tip part 212 formed by crimping also before crimping. In other words, the convex portion 411 overlaps the caulking portion 210 deformed by caulking when viewed in the Z-axis direction.

  Further, the convex portion 411 extends to the outside of the tip end portion 212 of the crimping portion 210 deformed by crimping as viewed in the Z-axis direction. Thereby, the outer periphery of the convex part 411 protrudes from the front-end | tip part 212 of the crimping | crimped part 210 over the perimeter. Note that the outer peripheral edge of the distal end portion 212 of the caulking portion 210 is within the outer peripheral surface 413 of the convex portion 411 when viewed in the Z-axis direction. With the outer peripheral edge of the tip 212 as a boundary, the pressure changes greatly between the inside and the outside. As a result, the amount of compression of the lower gasket 400 differs greatly between the inside and outside of the outer peripheral edge of the tip end portion 212, and there is a risk that a level difference will occur in the lower gasket 400 after crimping. However, as described above, if the outer peripheral edge of the distal end portion 212 of the caulking portion 210 is within the outer peripheral surface 413 that is a tapered surface, the convex portion 411 is thicker on the inner side of the outer peripheral edge of the distal end portion 212 before the caulking. The convex part 411 is thin outside the periphery. In other words, the difference in thickness can suppress the occurrence of a step after caulking.

  In particular, in this embodiment, since the tip surface 411a of the convex portion 411 is a flat surface, pressure during crimping can be evenly received by the convex portion 411, and the flatness of the entire convex portion 411 after crimping is maintained. It is possible.

[3 Manufacturing method]
Next, a method for manufacturing the electricity storage device 10 according to this embodiment will be described. In addition, although the case where an operator assembles the electrical storage element 10 is illustrated here, an assembly apparatus may assemble the electrical storage element 10.

  First, as shown in FIG. 6, the operator inserts the cylindrical portion 305 of the upper gasket 300 into the first through hole 120 a of the lid 120. Next, the operator inserts the caulking portion 210 of the electrode terminal 200 into the through hole 300 a of the upper gasket 300. Thereafter, the operator inserts the cylindrical portion 305 of the upper gasket 300 into the second through hole 410a of the lower gasket 400, and then inserts the crimped portion 210 of the electrode terminal 200 into the third through hole 510a of the current collector 500. insert. As described above, when the lid 120, the lower gasket 400, and the current collector 500 are overlapped in this order, the first through hole 120a, with the convex portion 411 facing the current collector 500, The second through hole 410a and the third through hole 510a communicate with each other. In this state, the axial crimping portion 210 of the electrode terminal 200 is inserted through the first through hole 120a, the second through hole 410a, and the third through hole 510a.

  Then, the operator compresses the convex part 411 via the current collector 500 by the caulking by caulking the caulking part 210. Specifically, when the shaft-like caulking portion 210 is caulked, the tip portion 212 of the caulking portion 210 is pressed so as to spread outward, and is closely attached to the surface of the terminal connection portion 510 of the current collector 500 over the entire circumference. To do. Thereby, the adhesiveness of the front-end | tip part 212 of the crimping | crimped part 210 and the terminal connection part 510 is improved. In addition, the terminal connection portion 510, the upper gasket 300, the lower gasket 400, and the lid 120 of the current collector 500 are tightened by this caulking. Thereby, the space | interval of the cover body 120 and the electrical power collector 500 becomes narrow, and the convex part 411 of the lower gasket 400 is compressed, and it will be in the state shown in FIG.

  In the same process, the worker attaches the upper gasket 300, the lower gasket 400, the current collector 500, and the electrode terminal 200 to the positive electrode side of the lid 120. Next, the worker attaches the negative electrode of the electrode body 600 to the electrode body connection portion 520 of the current collector 500 on the negative electrode side, and attaches the positive electrode of the electrode body 600 to the electrode body connection portion 520 of the current collector 500 on the positive electrode side. .

  Thereafter, the operator houses the electrode body 600 in the container body 110, welds the lid body 120 to the container body 110, and assembles the container 100. Next, the operator injects the electrolytic solution into the container 100 from a liquid injection port (not shown), and then welds the liquid injection stopper to the lid body 120 to close the liquid injection port. To manufacture.

[4 Explanation of effects]
As described above, according to the electricity storage device 10 according to the embodiment of the present invention, the container 100 having the first through hole 120a and the second through hole 410a communicating with the first through hole 120a are provided. Current collector 500 (first member) that has lower gasket 400 (insulating member) facing each other and third through hole 510a communicating with first through hole 120a and second through hole 410a and sandwiches lower gasket 400 together with container 100. Conductive member) and a crimped portion 210 that is crimped in a state of being inserted into the first through-hole 120a, the second through-hole 410a, and the third through-hole 510a, and the crimped portion 210 contacts the current collector 500 An electrode terminal 200 (second conductive member), and a ring protruding toward the current collector 500 before caulking around the second through hole 410a in the lower gasket 400. Protrusion 411 is provided for.

  Moreover, according to the manufacturing method of the electrical storage element 10 according to the embodiment of the present invention, the container 100 having the first through hole 120a, and the annular shape provided around the second through hole 410a and the second through hole 410a. When the lower gasket 400 having the convex portion 411 and the current collector 500 having the third through hole 510a are overlapped in this order, the first penetration is made with the convex portion 411 facing the current collector 500. The hole 120a, the second through-hole 410a, and the third through-hole 510a are communicated, and the shaft-shaped caulking portion 210 of the electrode terminal 200 is inserted into the first through-hole 120a, the second through-hole 410a, and the third through-hole 510a. Later, the convex portion 411 is compressed through the current collector 500 by the caulking by caulking the caulking portion 210.

  According to this, since the periphery of the second through-hole 410a in the lower gasket 400 is the convex portion 411 protruding toward the current collector 500, even if the convex portion 411 is compressed by caulking, Flatness can be maintained. Therefore, the deformation of the current collector 500 due to the deformation of the lower gasket 400 is suppressed, and the flatness of the current collector 500 can be maintained. In addition, the deformation of the current collector 500 may cause a decrease in strength and an assembly failure. However, if the flatness of the current collector 500 can be maintained, a decrease in strength and an assembly failure can be suppressed.

  Moreover, the convex part 411 can also be used as a mark at the time of positioning at the time of assembly. If there is a mark, positioning becomes easy and each member can be arranged at an accurate position.

  The convex portion 411 has a flat tip surface 411a.

  According to this, since the front end surface 411a of the convex portion 411 is a flat surface, the pressure during crimping can be evenly received by the convex portion 411, and the flatness of the entire convex portion 411 after crimping can be maintained. It is. Therefore, the deformation of the current collector 500 due to the deformation of the lower gasket 400 can be further suppressed.

  In addition, the convex portion 411 overlaps the caulking portion 210 when the second through hole 410a is viewed in the axial direction (viewed in the Z-axis direction).

  According to this, since the convex part 411 overlaps with the caulking part 210, the part that is most pressurized during caulking, that is, the part that is compressed most, can be the convex part 411. Thereby, the flatness of the convex part 411 after compression and another area | region (lower surface of the top-plate part 410) can be maintained reliably.

  Further, the convex portion 411 extends to the outside of the caulking portion 210 when the second through hole 410a is viewed in the axial direction.

  According to this, since the convex part 411 extends to the outside of the caulking part 210, the part that is most pressurized during caulking, that is, the part that is compressed most, can be received by the entire convex part 411. Thereby, the flatness of the convex part 411 after compression and another area | region can be maintained more reliably.

  Further, the surface 411b on the second through hole 410a side of the convex portion 411 and the inner peripheral surface 410b forming the second through hole 410a are flush with each other.

  According to this, since the surface 411b on the second through hole 410a side of the convex portion 411 and the inner peripheral surface 410b forming the second through hole 410a are flush with each other, the convex portion 411 is compressed by caulking. The convex portion 411 is likely to move closer to the second through hole 410a side. Therefore, the convex portion 411 after compression deformation is brought into close contact with the member (cylindrical portion 305 of the upper gasket 300) in the second through hole 410a, so that insulation and air tightness can be improved.

  Moreover, the outer peripheral surface 413 in the convex part 411 is a taper surface which becomes thin toward the front-end | tip.

  According to this, since the outer peripheral surface 413 of the convex portion 411 is a tapered surface that becomes narrower toward the tip, when the convex portion 411 is compressed by caulking, the convex portion 411 moves toward the second through-hole 410a. It becomes easy to approach. Therefore, the convex portion 411 after compression deformation is brought into close contact with the member (cylindrical portion 305 of the upper gasket 300) in the second through hole 410a, so that insulation and air tightness can be improved.

  In the present embodiment, the case where the convex portion 411 after compression deformation is in close contact with the cylindrical portion 305 of the upper gasket 300 is illustrated. However, when only the caulking portion 210 of the electrode terminal 200 is disposed in the second through-hole 410a, the convex portion 411 after compression deformation is brought into close contact with the caulking portion 210. Even in this case, insulation and airtightness can be improved.

  The first conductive member is the current collector 500, and the second conductive member is the electrode terminal 200.

  According to this, since the first conductive member is the current collector 500 and the second conductive member is the electrode terminal 200, the crimping portion 210 is provided on the electrode terminal 200. For this reason, the caulking portion 210 is positioned inside the container 100. That is, in the electricity storage device 10 in which a so-called inner caulking structure is adopted, deformation of the current collector 500 due to deformation of the lower gasket 400 can be suppressed.

[5. Description of Modification of Embodiment]
Next, a modification of the above embodiment will be described. In the following description, parts that are the same as those in the above embodiment or other modifications may be given the same reference numerals and explanation thereof may be omitted.

[Modification 1]
FIG. 8 is a cross-sectional view showing a configuration of a lower gasket 400C according to Modification 1 of the present embodiment. Specifically, FIG. 8 corresponds to FIG. As shown in FIG. 8, the convex part 411c of the lower gasket 400C according to Modification 1 is formed in a cylindrical shape. That is, the lower gasket 400C according to Modification 1 is different from the lower gasket 400 according to the above-described embodiment in that the outer peripheral surface 413c of the convex portion 411c is a plane that is substantially orthogonal to the lower surface of the top plate portion 410. ing.

[Modification 2]
FIG. 9 is a cross-sectional view showing a configuration of a lower gasket 400D according to Modification 2 of the present embodiment. Specifically, FIG. 9 is a diagram corresponding to FIG. As shown in FIG. 9, the convex part 411d of the lower gasket 400D according to Modification 2 is formed in a cylindrical shape. Further, an annular groove 415d is formed in the tip surface 411ad of the convex portion 411d when viewed in the Z-axis direction. That is, the lower gasket 400D according to Modification 2 is different from the lower gasket 400 according to the above-described embodiment in that the convex portion 411d is formed in a double annular shape. In addition, the convex part may be formed in the cyclic | annular form more than triple.

[Modification 3]
FIG. 10 is a cross-sectional view showing a configuration of a lower gasket 400E according to Modification 3 of the present embodiment. Specifically, FIG. 10 corresponds to FIG. As shown in FIG. 10, the convex part 411e of the lower gasket 400E which concerns on the modification 3 is formed in the small cylindrical shape, and the cyclic | annular collar part 416e is provided in the outer peripheral part of the front-end | tip part. That is, the lower gasket 400E according to the modification 3 is different from the lower gasket 400 according to the above-described embodiment in that the convex portion 411e includes the flange portion 416e.

[Modification 4]
FIG. 11 is a cross-sectional view showing a configuration of a lower gasket 400F according to Modification 4 of the present embodiment. Specifically, FIG. 11 corresponds to FIG. As shown in FIG. 11, the convex part 411f of the lower gasket 400F according to the modification 4 is formed in a cylindrical shape, and an annular step part 417f protruding outward is formed on the outer peripheral part of the base end part. Is provided. That is, the lower gasket 400F according to the modification 4 is different from the lower gasket 400 according to the above-described embodiment in that the convex portion 411f includes a step portion 417f.

[Modification 5]
FIG. 12 is a cross-sectional view illustrating configurations of an electrode terminal 200G, an upper gasket 300G, a lower gasket 400G, and a current collector 500G according to Modification 5 of the present embodiment. Specifically, FIG. 12 corresponds to FIG.

  In the above embodiment, the case where the first conductive member is the current collector 500 and the second conductive member is the electrode terminal 200 is illustrated. In the fifth modification, the case where the first conductive member is the electrode terminal 200G and the second conductive member is the current collector 500G is illustrated.

  The electrode terminal 200G is formed with a through hole 250g, which is a third through hole, at a substantially central portion of the protruding portion 211g. An axial caulking portion 550g is provided on the upper surface of the terminal connection portion 510g of the current collector 500G. The lower surface of the top plate portion 410g in the lower gasket 400G is flat as a whole. That is, the convex part 411 is not provided around the through-hole 410g in the lower gasket 400G.

  The upper gasket 300G is an example of an insulating member that has a through hole 310g that is a second through hole and faces the lid 120. An annular convex portion 320g is provided on the bottom surface of the concave portion 302g in the upper gasket 300G as viewed in the Z-axis direction. The protrusion 320g is provided around the through hole 310g. A surface 321g on the through hole 310g side of the protrusion 320g is flush with an inner peripheral surface 311g forming the through hole 310g. A surface 321g on the through hole 310g side of the convex portion 320g is an inner peripheral surface of the convex portion 320g.

  Moreover, the outer peripheral surface 322g in the convex part 320g is a taper surface which becomes thin toward the front-end | tip. Moreover, the front end surface 323g of the convex part 320g is formed in a plane. Specifically, the tip surface 323g is a plane parallel to the XY plane. That is, the front end surface 323g is a plane parallel to the bottom surface of the recess 302g and the terminal connection portion 510g of the current collector 500G.

  When assembling the electrode terminal 200G, the upper gasket 300G, the lower gasket 400G, and the current collector 500G to the lid body 120, the operator inserts the cylindrical portion 305 of the upper gasket 300G into the first through hole 120a of the lid body 120. Insert. Next, the operator attaches the lower gasket 400G to the upper gasket 300G by inserting the cylindrical portion 305 of the upper gasket 300G into the through hole 410g of the lower gasket 400G. Thereafter, the operator inserts the caulking portion 550g of the current collector 500G into the through hole 310g of the upper gasket 300G. As described above, when the lid 120, the upper gasket 300G, and the current collector 500G are overlapped in this order, the through holes 120a, 310g, 250 g is communicated. In this state, the axial caulking portion 550g of the current collector 500G is inserted through each of the through holes 120a, 310g, and 250g.

  Thereafter, the operator caulks the caulking portion 550g, thereby compressing the convex portion 320g via the electrode terminal 200G by the caulking. Specifically, when the shaft-like caulking portion 550g is caulked, the tip end portion of the caulking portion 550g is pressed so as to spread outward, and closely contacts the upper surface of the electrode terminal 200G over the entire circumference. Thereby, the adhesiveness of the front-end | tip part of the crimping | crimped part 550g and the electrode terminal 200G is improved. Further, the electrode terminal 200G, the upper gasket 300G, the lower gasket 400G, and the lid 120 are tightened by this caulking. Thereby, the space | interval of the cover body 120 and the electrode terminal 200G becomes narrow, and the convex part 320g of the upper gasket 300G is compressed. Due to this compression deformation, the convex portion 320g and the other region (the bottom surface of the concave portion 302g) are substantially flush with each other. In the upper gasket 300G, if the bottom surface of the concave portion 302g and the convex portion 320g are substantially flush with each other, it becomes difficult to deform the electrode terminal 200G immediately above the upper gasket 300G.

  As described above, in Modification 5, the first conductive member is the electrode terminal 200G, and the second conductive member is the current collector 500G.

  According to this, since the first conductive member is the electrode terminal 200G and the second conductive member is the current collector 500G, the crimping portion 550g is provided on the current collector 500G. For this reason, the caulking part 550g is located outside the container 100. That is, in the electric storage element employing the so-called outer caulking structure, the deformation of the electrode terminal 200G due to the deformation of the upper gasket 300G can be suppressed.

(Other variations)
The power storage device according to the embodiment of the present invention and the modification thereof has been described above, but the present invention is not limited to this embodiment and the modification thereof. In other words, it should be considered that the embodiment and its modification disclosed this time are illustrative and not restrictive in all respects. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  For example, in the above-described embodiment, the annular convex portion 411 that is continuous as a whole is illustrated, but the annular convex portion may be intermittently formed.

  Moreover, in the said embodiment, although the case where the front end surface 411a of the convex part 411 was a plane was illustrated, the front end surface of a convex part may be non-planar.

  Moreover, in the said embodiment, although the case where the convex part 411 overlapped with the front-end | tip part 212 of the caulking part 210 in the axial direction view of the 2nd through-hole 410a was illustrated, the convex part has overlapped with the front-end | tip part of the caulking part. It does not have to be.

  Moreover, in the said embodiment, although the case where the convex part 411 extended to the outward of the front-end | tip part 212 of the crimping part 210 was illustrated, the convex part does not need to extend to the outward of the front-end | tip part of a crimping part. .

  Moreover, although the said embodiment demonstrated the case where the surface 411b by the side of the 2nd through-hole 410a in the convex part 411 and the internal peripheral surface 410b which makes the 2nd through-hole 410a were flush | planar, these are flush. It does not have to be.

  In the above-described embodiment, the electrode body 600 is a so-called vertical winding electrode body in which the winding axis is parallel to the lid body 120. However, the electrode body 600 may be a so-called laterally wound electrode body in which the winding axis is perpendicular to the lid body 120. The shape of the electrode body 600 is not limited to a wound type, but a stack type in which flat plate plates are stacked, or a shape in which the electrode plate and / or the separator are folded in a bellows shape (a rectangular electrode plate is formed by folding the separator in a zigzag manner). It is also possible to use a sandwiching form, a form in which the electrode plate and the separator are overlapped and then folded in a zigzag manner.

  In the above embodiment, both the positive electrode side and the negative electrode side have the above-described configuration, but only one of the positive electrode side and the negative electrode side has the above-described configuration. Also good.

  In addition, embodiments constructed by arbitrarily combining the constituent elements included in the above-described embodiment and its modifications are also included in the scope of the present invention.

  Further, the present invention can be realized not only as such a power storage element, but also as a lower gasket or an upper gasket provided in the power storage element.

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

DESCRIPTION OF SYMBOLS 10 Power storage element 100 Container 110 Container main body 120 Lid 120a 1st through-hole 121, 211, 211g, 301 Projection part 122, 302, 302g, 412 Recess 125 Gas exhaust valve 200 Electrode terminal (2nd electrically-conductive member)
200G electrode terminal (first conductive member)
210 Caulking portion 212 Tip portion 250g Through hole (third through hole)
300 Upper gasket 300a, 411g Through hole 300G Upper gasket (insulating member)
305 Cylindrical part 310g Through hole (second through hole)
311g, 410b Inner peripheral surface 321g, 411b Surface 322g, 413, 413c Outer peripheral surface 323g, 411a, 411ad Tip surface 400, 400C, 400D, 400E, 400F Lower gasket (insulating member)
400G Lower gasket 410, 410g Top plate portion 410a Second through-holes 411, 411a, 411c, 411d, 411e, 411f, 320g Convex portion 415d Groove 416e Gutter portion 417f Stepped portion 420 Wall portion 421 Notch portion 422 Inclined portion 500 Current collector Body (first conductive member)
500G current collector (second conductive member)
510, 510g Terminal connecting portion 510a Third through hole 520 Electrode body connecting portion 550g Caulking portion 600 Electrode body 610 End

Claims (7)

A container having a first through hole;
An insulating member having a second through hole communicating with the first through hole and facing the container;
A first conductive member having a third through hole communicating with the first through hole and the second through hole, and sandwiching the insulating member together with the container;
A second conductive member that has a crimped portion that is crimped in a state of being inserted into the first through hole, the second through hole, and the third through hole, and the crimped portion is in contact with the first conductive member; With
An annular convex portion protruding toward the first conductive member is provided around the second through hole in the insulating member before crimping. The power storage device according to claim 1, wherein the convex portion overlaps the crimped portion when the second through hole is viewed in the axial direction. The electric storage element according to claim 2, wherein the convex portion extends to the outside of the caulking portion when the second through hole is viewed in the axial direction. The electric storage element according to any one of claims 1 to 3, wherein a surface of the convex portion on the second through hole side and an inner peripheral surface forming the second through hole are flush with each other. The electric storage element according to any one of claims 1 to 4, wherein an outer peripheral surface of the convex portion is a tapered surface that becomes narrower toward a tip. The first conductive member is one of a current collector and an electrode terminal;
The power storage device according to claim 1, wherein the second conductive member is the other. The container having the first through hole, the insulating member having the second through hole and the annular convex portion provided around the second through hole, and the first conductive member having the third through hole are arranged in this order. In the state where the convex portion is directed to the first conductive member, the first through hole, the second through hole, and the third through hole are communicated with each other.
After the shaft-shaped crimping portion of the second conductive member is inserted into the first through hole, the second through hole, and the third through hole, the first conductive member is crimped by the crimping. A method for manufacturing a power storage element, wherein the convex portion is compressed via a member.

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