Energy Storage Devices

Abstract

This power storage device comprises: a case that accommodates an electrode group including first and second electrodes, and that has an opening; and a sealing body that closes the opening of the case. The sealing body is provided with: a ring-shaped sealing plate that has a first surface, a second surface opposite therefrom, and a first through hole; a terminal plate that has a third surface facing the first surface of the sealing plate, and a fourth surface opposite therefrom; and a ring-shaped gasket that is interposed between the sealing plate and the terminal plate, and has a second through hole overlapping with the first through hole. The sealing plate has a first recessed portion where the first surface is recessed, and an outer peripheral portion continuous therefrom. The terminal plate has: a projecting portion that projects from the third surface toward the sealing plate, and has an end surface closing the first and second through holes; and a flange portion that extends from the projecting portion in a second direction intersecting a first direction. The projecting portion is accommodated in the first recessed portion. The outer peripheral portion of the sealing plate and the opening end portion of the case are joined. The first electrode is electrically connected to the terminal plate. The second electrode is electrically connected to the case.

Description

[Technical field]

[0001] The present disclosure relates to an electricity storage device. [Background technology]

[0002] Electricity storage devices are widely used as driving sources for vehicles, electronic devices, etc. In general, an electricity storage device includes a case that houses an electrode group including a first electrode and a second electrode and has an opening, and a sealing body that closes the opening of the case. When the first electrode is electrically connected to the case, the second electrode is connected to a terminal portion provided on the sealing body. The terminal portion needs to be electrically insulated from the case.

[0003] Patent Document 1 teaches a nonaqueous electrolyte secondary battery including a cylindrical battery case with a bottom, a power generating element housed in the case, and a sealing plate that closes the opening of the battery case, wherein the sealing plate has a flange portion formed to roughly match the shape of the opening of the battery case, a boss portion that holds a gas discharge means that breaks when the pressure inside the battery case reaches a predetermined value, and a protrusion that protrudes inward from the boss portion, and wherein a cap that also serves as one of the electrode terminals, an upper thin metal plate, a lower thin metal plate, and a gasket are arranged between the protrusion and a bent portion where one end of the boss portion is bent inward. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2004-241171 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in order to provide the boss and protrusion on the sealing plate of Patent Document 1, complex processing is required. For example, it is necessary to form one of the boss and protrusion on the sealing plate formed with the other by welding or forging. Manufacturing such a sealing plate with high precision is costly. Therefore, an object of the present disclosure is to provide an electricity storage device having a sealing body that is easy to process. [Means for solving the problem]

[0006] One aspect of the present disclosure includes an electrode group including a first electrode and a second electrode, a case that houses the electrode group and has an opening, and a sealing body that closes the opening of the case, the sealing body having a first surface and a second surface opposite to the first surface, an annular sealing plate having a first through hole, a terminal plate having a third surface facing the first surface of the sealing plate in a first direction and a fourth surface opposite to the third surface, and an annular gasket interposed between the sealing plate and the terminal plate and having a second through hole that overlaps with the first through hole, the sealing plate having the first through hole and a first surface that is recessed. the terminal plate has a protrusion protruding from the third surface toward the sealing plate and having an end face blocking the first through hole and the second through hole, and a flange portion extending from the protrusion in a second direction intersecting the first direction, the protrusion of the terminal plate is accommodated in the first recess of the sealing plate via the gasket, the peripheral edge of the outer periphery of the sealing plate is joined to an opening end surrounding the opening of the case, the first electrode is electrically connected to the protrusion of the terminal plate, and the second electrode is electrically connected to the case. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide an electricity storage device having a sealing body that can be easily formed because the gap between the sealing plate and the terminal plate can be sealed even without a protrusion. [Brief description of the drawings]

[0008] [Figure 1]1 is a cross-sectional view illustrating a structure of an example of an electricity storage device according to an embodiment of the present disclosure. [Diagram 2] 10 is a cross-sectional view of a modified example of an electricity storage device according to an embodiment of the present disclosure. [Figure 3A] FIG. 11 is a cross-sectional view of a modified example of a sealing body according to an embodiment of the present disclosure. [Figure 3B] FIG. 11 is a cross-sectional view of a main portion of another modified example of a sealing body according to an embodiment of the present disclosure. [Figure 4] FIG. 2 is a process diagram showing the first half of a manufacturing process for a sealing body according to an embodiment of the present disclosure. [Diagram 5] 4A to 4C are process diagrams showing the second half of a manufacturing process for a sealing body according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The electric storage device according to one aspect of the present disclosure includes an electrode group including a first electrode and a second electrode, a case that houses the electrode group and has an opening, and a sealing body that closes the opening of the case. The case has, for example, a cylindrical shape. The case has, for example, a tube portion, an open end that is continuous with one end of the tube portion and corresponds to the opening, and a bottom that closes the other end of the tube portion. The case is conductive. The case is made of, for example, a metal. The metal that constitutes the case may be made of aluminum, copper, iron, stainless steel, nickel, or an alloy that combines these metals. The electrode group is, for example, made by winding a first electrode and a second electrode with a separator interposed therebetween. When the electric storage device is a battery, one of the first electrode and the second electrode is a positive electrode, and the other is a negative electrode.

[0010] The sealing body includes an annular sealing plate having a first surface and a second surface opposite thereto and a first through hole, a terminal plate having a third surface facing the first surface of the sealing plate in a first direction and a fourth surface opposite thereto, and an annular gasket interposed between the sealing plate and the terminal plate and having a second through hole overlapping with the first through hole. The gasket is interposed between the sealing plate and the terminal plate to insulate them from each other. The gasket includes polypropylene (PP), polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), perfluoroalkoxyalkane (PFA), polyether ether ketone (PEEK), and the like. The sealing body seals the opening of the case by joining the periphery of the sealing plate to the opening end of the case. There is a sufficient distance between the periphery of the sealing plate and the gasket interposed between the sealing plate and the terminal plate. Therefore, when the peripheral edge of the outer periphery of the sealing plate and the open end of the case are joined by welding, the gasket is less likely to deteriorate due to heat during welding.

[0011] The sealing plate is conductive. The sealing plate may be made of, for example, a metal. The metal constituting the sealing plate may be made of aluminum, copper, iron, stainless steel, nickel, or an alloy combining these metals. When the sealing plate is made of the same material as the case, the reliability of the joint between the sealing plate and the case is increased. The sealing plate has a first recess having a first through hole and a recessed first surface, and an outer periphery continuous with the periphery of the first recess. That is, the first surface of the sealing plate has an inner bottom surface of the first recess and an inner periphery of the first recess extending from the inner bottom surface in a first direction. Such a sealing plate can be easily formed with high accuracy at low cost by combining punching and pressing. The bottom of the first recess may be made of a thin-walled portion that is thinner than the outer periphery.

[0012] The terminal plate is conductive. The terminal plate may be made of, for example, a metal. The metal constituting the terminal plate may be made of aluminum, copper, iron, stainless steel, nickel, or an alloy combining these metals. When the terminal plate is made of the same material as the lead, the reliability of the joint between the sealing plate and the lead is increased. The terminal plate has a protruding portion protruding from the third surface toward the sealing plate, and a flange portion extending from the protruding portion in a second direction (or a direction perpendicular to the first direction) which is the radial direction of the sealing plate. The protruding portion has an end face on the third surface side that closes the first through hole and the second through hole. Such a terminal plate can be easily formed with high accuracy at low cost by combining punching and pressing. The protruding portion may be made of a thick portion that is thicker than the flange portion.

[0013] The protrusion of the terminal plate is accommodated in the first recess of the sealing plate via a gasket. That is, the third surface of the terminal plate has an end face of the protrusion that faces the inner bottom surface of the first recess and an outer circumferential surface of the protrusion that extends in the first direction from the end face. The peripheral portion of the end face of the protrusion faces the inner bottom surface of the first recess of the sealing plate.

[0014] The first electrode is electrically connected to the protruding portion of the terminal plate. The second electrode is electrically connected to the case, and the sealing plate joined to the case has the same polarity as the second electrode.

[0015] The gasket may have a first sealing portion formed around the second through hole, a cylindrical second sealing portion continuous with the first sealing portion, and an annular third sealing portion continuous with the second sealing portion. This enhances the sealing performance between the sealing plate and the terminal plate. For example, the first sealing portion is interposed between an end face of the protruding portion of the terminal plate and an inner bottom surface of the first recess of the sealing plate. The second sealing portion extends from the first sealing portion in a first direction and is interposed between an inner peripheral surface of the first recess and an outer peripheral surface of the protruding portion. The third sealing portion extends from the second sealing portion in a second direction and is interposed between a flange portion of the terminal plate and an outer peripheral portion of the sealing plate.

[0016] The opening edge of the first through hole of the first recess of the sealing plate may have a first hook portion that protrudes so as to press against the first sealing portion of the gasket. For example, this first hook portion is bent toward the first sealing portion. When the first hook portion presses against the first sealing portion, the bonding force between the sealing plate and the terminal plate is increased, and the sealing body improves the sealing of the inside of the case.

[0017] The end face of the terminal plate may have a rib (hereinafter referred to as the first rib) that protrudes toward the first sealing portion. When viewed from the first direction, the first rib may be formed in an annular shape. In this case, the bonding strength between the sealing plate and the terminal plate is further increased by engaging the first hook portion with the inner peripheral surface of the first rib.

[0018] The tip of the first hook portion may be located inward of the first rib in the second direction. This allows the first hook portion to sandwich the rib together with the inner peripheral surface of the first recess via the gasket. As a result, the gasket is compressed between the inner peripheral surface of the first recess and the rib, and between the first hook portion and the rib, improving the reliability of the seal between the sealing plate and the terminal plate.

[0019] The protruding portion may have a second recess in which the third surface is recessed. Furthermore, the fourth surface may have a first groove surrounding the second recess. In this case, the first groove may be formed to correspond to the first rib. For example, the first groove may be formed in the fourth surface, causing the third surface to protrude by the first groove, thereby forming the first rib.

[0020] In the first groove, the dimension D1 in the second direction at an arbitrary position P1 may be smaller than the dimension D2 in the second direction at a position P2 that is closer to the third surface than position P1 in the first direction. For example, the dimension in the second direction of the first groove may be smaller at a position farthest from the third surface in the first direction (i.e., near the opening of the first groove) than at a position closer to the third surface (e.g., the deepest part of the first groove or near the center in the depth direction of the first groove). In this case, the dimension in the second direction of the most protruding part of the first rib is larger than the dimension in the second direction of the base part of the first rib, so that the first hook portion can be more firmly engaged with the inner peripheral surface of the first rib.

[0021] The inner peripheral edge of the first sealing portion may be bent toward the second recess together with the first hook portion. This increases the adhesion between the first hook portion and the first sealing portion, and increases the compression ratio of the first sealing portion. This further increases the sealing ability of the sealing body to seal the inside of the case.

[0022] The flange portion of the terminal plate may have a second hook portion that presses the third sealing portion. For example, the second hook portion is bent toward the third sealing portion. This increases the adhesion between the second hook portion and the third sealing portion, and increases the compression rate of the third sealing portion. Therefore, the sealing between the outer periphery of the sealing body and the terminal plate is further increased. Note that the sealing between the terminal plate and the sealing plate in the power storage device of the present disclosure does not need to include the first hook portion or the second hook portion. For example, the distance between the inner periphery of the first recess and the outer periphery of the protrusion may be made smaller than the thickness of the second sealing portion of the gasket, and the second sealing portion may be compressed by the inner periphery and the outer periphery to seal between the terminal plate and the sealing plate.

[0023] The second surface of the outer periphery of the sealing plate may have a second groove surrounding the first recess. The second groove may be formed to protrude the first surface, forming a second rib. Also, in the second groove, a dimension D3 in the second direction at an arbitrary position P3 may be smaller than a dimension D4 in the second direction at a position P4 located closer to the first surface than the position P3 in the first direction. For example, the dimension in the second direction of the second groove may be smaller at a position farthest from the first surface in the first direction (i.e., near the opening of the second groove) than at a position closer to the first surface (e.g., the deepest part of the second groove or near the center in the depth direction of the second groove). In this case, the most protruding part of the second rib has a dimension in the second direction larger than the root part of the second rib, so that the second hook part can be firmly engaged with the outer periphery of the second rib via the gasket.

[0024] The type of the power storage device is not particularly limited, and examples thereof include a primary battery, a secondary battery, a lithium ion capacitor, an electric double layer capacitor, a solid electrolytic capacitor, etc. Among them, a non-aqueous electrolyte secondary battery (including an all-solid-state battery) such as a lithium ion secondary battery having a high energy density can be preferably used.

[0025] Hereinafter, an electricity storage device according to an embodiment of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the following.

[0026] Fig. 1 is a cross-sectional view showing an example of the structure of an electricity storage device 100 according to an embodiment. Fig. 2 is a cross-sectional view of an electricity storage device 100A according to a modified example of the electricity storage device 100. The electricity storage device 100 includes a cylindrical case 110 having an opening 101, an electrode group 120 including a first electrode and a second electrode housed in the case 110, and a sealing body 130 that seals the opening 101.

[0027] Sealing body 130 includes sealing plate 131, terminal plate 132, and insulating gasket 133 interposed therebetween. Case 110 includes cylindrical tube portion 111, opening end 112 that is continuous with one end of tube portion 111 and corresponds to opening 101, and bottom portion 113 that closes the other end of tube portion 111.

[0028] The sealing plate 131 has a first surface 131A and a second surface 131B opposite to the first surface 131A. The sealing plate 131 is annular, and has a first recess 1311 in the form of an inner flange where the first surface 131A is recessed on the inside, and has an outer circumferential portion 1312 around the first recess 1311.

[0029] The first recess 1311 has a first through hole 1311h in the center. The area of ​​the first surface 131A corresponding to the first recess 1311 has an inner bottom surface of the first recess and an inner circumferential surface extending from the inner bottom surface in a first direction. Here, the first direction refers to the axial direction Da of the annular sealing plate 131.

[0030] The periphery of the outer peripheral portion 1312 is joined to the opening end 112 of the case 110 at a welded portion WP. That is, the sealing plate 131 is electrically connected to the case 110. Since the case 110 is connected to the second electrode, the sealing plate 131 is electrically continuous with the second electrode. In addition, a shallow cylindrical wall 1312W extending toward the inside of the case is provided on the periphery of the outer peripheral portion 1312 in order to increase the dimension in the axial direction Da of the weld mark between the sealing body 130 and the opening end 112 of the case (i.e., the depth of the weld mark). This configuration increases the strength of the weld mark. Therefore, the reliability of the seal between the sealing body and the case can be improved.

[0031] Terminal plate 132 has a third surface 132A facing first surface 131A of sealing plate 131 in the first direction, and a fourth surface 132B opposite to third surface 132A. Third surface 132A has an end face of protrusion 1321 facing the inner bottom surface of first recess 1311 of sealing plate 131, and an outer circumferential surface of protrusion 1321 extending from the end face in the first direction.

[0032] The terminal plate 132 has a protruding portion 1321 protruding from the third surface 132A toward the sealing plate 131, and a flange portion 1322 extending from the protruding portion 1321 in a second direction Dr which is a radial direction of the sealing plate. The second direction Dr is perpendicular to the first direction Da. The first electrode is electrically connected to the protruding portion 1321 of the terminal plate 132.

[0033] Gasket 133 is annular, is interposed between sealing plate 131 and terminal plate 132, and has second through hole 133h in the center. Protrusion 1321 of terminal plate 132 is accommodated in first recess 1311 of sealing plate 131 via gasket 133. In this case, second through hole 133h of gasket 133 may overlap concentrically with first through hole 1311h of the sealing plate.

[0034] The gasket 133 has a first sealing portion 1331 formed around the second through hole 133h, a cylindrical second sealing portion 1332, and an annular third sealing portion 1333. The first sealing portion 1331 is interposed between an end face of the protruding portion 1321 of the terminal plate 132 and an inner bottom surface of the first recess 1311 of the sealing plate 131. The cylindrical second sealing portion 1332 extends from the first sealing portion 1331 in the first direction Da and is interposed between the outer peripheral surface of the protruding portion 1321 of the terminal plate 132 and the inner peripheral surface of the first recess 1311 of the sealing plate 131. The annular third sealing portion extends from the second sealing portion 1332 in the second direction Dr and is interposed between the flange portion 1322 of the terminal plate 132 and the outer peripheral portion 1312 of the sealing plate 131.

[0035] A first hook portion 131f is formed on the opening edge of the first through hole 1311h of the first recess 1311, bending toward the gasket 133 and pressing the first sealing portion 1331 of the gasket 133. A first rib 1323 protruding toward the first sealing portion 1331 is formed on the end face of the protruding portion 1321 of the terminal board 132. The first hook portion 131f engages with the first rib 1323 via the first sealing portion 1331, thereby integrating the sealing plate 131 and the terminal board 132 and sealing the second through hole 133h. That is, the sealing plate 131 is crimped to the third surface 132A of the terminal board 132 via the third sealing portion 1333 by the first hook portion 131f.

[0036] The tip of first hook portion 131f is located inward of the case from first rib 1323 when viewed from the first direction Da. This allows first hook portion 131f to sandwich first rib 1323 together with the inner peripheral surface of first recess 1311 via gasket 133. Therefore, gasket 133 is compressed between the inner peripheral surface of first recess 1311 and first rib 1323 and between first hook portion 131f and first rib 1323, respectively, thereby improving the reliability of sealing between sealing plate 131 and terminal plate 132.

[0037] Meanwhile, second hook portions 132f that press against third sealing portion 1333 of gasket 133 are formed on flange portion 1322 of terminal board 132. That is, terminal board 132 is crimped to first surface 131A of sealing plate 131 via third sealing portion 1333 by second hook portions 132f.

[0038] An internal insulating plate 140 is disposed between the electrode group 120 and the sealing body 130, and the internal insulating plate 140 prevents contact between the electrode group 120 and the sealing body 130 or the case 110. A predetermined lead hole 141 is provided in the internal insulating plate 140. A lead 122 extending from a first electrode constituting the electrode group 120 passes through the lead hole 141 and is electrically connected to the inner surface of the terminal plate 132. Thus, the terminal plate 132 has the same polarity as the first electrode. On the other hand, a second electrode constituting the electrode group 120 is electrically connected to the case 110. Thus, the case 110 has the same polarity as the second electrode.

[0039] 1, in the above configuration, second surface 131B of outer periphery 1312 of sealing plate 131 and an end surface (third surface 132A) of protruding portion 1321 of terminal plate 132 may be located at approximately the same height in first direction Da. Therefore, when connecting external current collecting leads to sealing plate 131 and terminal plate 132, they can be connected at approximately the same height.

[0040] The power storage device 100A according to the modified example of Fig. 2 has a sealing body having basically the same structure as the power storage device 100 of Fig. 1, but the fixing direction to the opening 101 of the case 110 is reversed. In the case of Fig. 1, the first recess 1311 of the sealing plate 131 protrudes in the first direction Da toward the outside of the case 110, and the height of the power storage device is increased accordingly. On the other hand, in the case of Fig. 2, the first recess 1311 of the sealing plate 131 protrudes in the first direction Da toward the inside of the case 110, and an increase in the height of the power storage device is suppressed.

[0041] However, in the case of FIG. 1, the internal pressure within the case acts in a direction that pushes up sealing plate 131 from terminal plate 132 via gasket 133, so that the sealing performance of sealing body 130 is relatively high.

[0042] In the modified example of FIG. 2 as well, the first surface 131A of the outer circumferential portion 1312 of the sealing plate 131 and the fourth surface 132B of the protruding portion 1321 of the terminal plate 132 may be located at approximately the same height in the first direction Da.

[0043] FIG. 3A is a cross-sectional view of a sealing body 130A according to a modification of the sealing body 130. A second recess 1324 is formed in the protruding portion 1321 of the terminal plate 132, in which the third surface 132A is recessed. A first groove portion 132G is formed in the fourth surface 132B of the terminal plate 132 so as to surround the second recess 1324. When the second recess 1324 and the first groove portion 132G are formed in this manner and the first sealing portion 1331 is pressed by the first hook portion 131f of the sealing plate 131, the inner peripheral edge of the first sealing portion 1331 is bent toward the second recess 1324 together with the first hook portion 131f, and the inner peripheral surface of the first rib 1323 is inclined toward the outside in the second direction Dr. As a result, the first hook portion 131f is more strongly engaged with the rib 1323 via the gasket 133, and the terminal plate 132 is firmly fixed to the sealing plate 131.

[0044] 3A, the dimension of the first groove 132G in the second direction Dr is smallest near the opening of the first groove 132G farthest from the first recess 1311 in the first direction Da, and is largest at the deepest part of the first groove 132G closest to the first recess 1311, but is not limited to this. For example, the dimension of the first groove 132G in the second direction Dr may be largest near the center of the first groove 132G in the depth direction.

[0045] 3B is a cross-sectional view of a main part of sealing body 130B according to another modified example of sealing body 130. Here, second surface 131B of outer periphery 1312 of sealing plate 131 has second groove 131G surrounding first recess 1311. Also, first surface 131A protrudes corresponding to second groove 131G and has second rib 1313. Meanwhile, protruding portion 1321 of terminal board 132 has second recess 1324 formed by recessing third surface 132A, as in FIG. 3A, and first groove 132G surrounding second recess 1324 formed on fourth surface 132B.

[0046] In this way, by forming the first groove portion 132G (first rib 1323) and the second groove portion 131G (second rib 1313), and pressing the first sealing portion 1331 with the first hook portion 131f of the sealing plate 131 and pressing the third sealing portion 1333 with the second hook portion 132f of the terminal plate 132, the sealing plate 131 and the terminal plate 132 are more firmly fixed together.

[0047] The structure of the sealing body may be modified in various ways without being limited to those shown in Figures 1 to 3. Modified examples of the sealing body will be described below with reference to the drawings, but the modified examples are not limited to those described below.

[0048] Next, an example of a method for manufacturing the sealing body 130A according to this embodiment will be described. Fig. 4 is a process diagram showing the first half of the manufacturing process for the sealing body 130A, and Fig. 5 is a process diagram showing the second half of the manufacturing process for the sealing body 130A.

[0049] First, the sealing plate 131 is prepared (FIG. 4(a)). The sealing plate 131 is annular having a first surface 131A and a second surface 131B on the opposite side thereof, and has a first recess 1311 formed by recessing the first surface 131A on the inside, and has an outer periphery 1312 around the first recess 1311. A first through hole 1311h is provided in the center of the first recess 1311.

[0050] Next, the gasket 133 is inserted into the first recess 1311 of the sealing plate 131 and the two are mated (FIG. 4(b)). The gasket 133 is annular, and has a cylindrical wall portion 133W that will later constitute the second sealing portion and the third sealing portion, and an inner flange-like annular base portion 133R that will later constitute the first sealing portion. A second through hole 133h is provided in the center of the annular base portion 133R. When the sealing plate 131 and the gasket 133 are mated, the first through hole 1311h and the second through hole 133h are arranged concentrically.

[0051] Next, the terminal plate 132 is inserted inside the cylindrical wall portion 133W of the gasket 133 to fit them together (FIG. 4(c)). The terminal plate 132 is disk-shaped and has a cylindrical wall portion 132W that will later form the flange portion 1322, and a bottom portion 132b that closes one end of the wall portion 132W. The bottom portion 132b forms a protruding portion that protrudes in the first direction Da when viewed from the flange portion 1322. A first rib 1323 is provided in an annular shape on the periphery of the bottom portion 132b, protruding toward the annular base portion 133R of the gasket 133, and the circular area surrounded by the first rib 1323 forms a second recessed portion 1324 in which the third surface 132A is recessed. The back side of the first rib 1323 forms the first groove portion 132G.

[0052] Next, a first mold 200 having a ring-shaped concave surface is abutted against the second surface 131B of the sealing plate 131, and a punch-shaped second mold 300 which presses the second recess 1324 is abutted against the fourth surface 132B of the terminal plate 132, and pressure is applied in a direction (first direction Da) in which the sealing plate 131 and the terminal plate 132 approach each other (Figures 4(d) and (e)).

[0053] Furthermore, pressure is applied in a direction (first direction Da) in which the sealing plate 131 and the terminal plate 132 approach each other, and the protruding portion 201 arranged at the center of the ring-shaped concave surface of the first mold 200 is brought into contact with the terminal plate 132 (FIG. 5(f)). At this time, the periphery of the first through hole 1311h of the first concave portion 1311 of the sealing plate 131 is bent to form the first hook portion 131f, and the first hook portion 131f is crimped to the bottom portion 132b (the second concave portion 1324 of the protruding portion) of the terminal plate 132 via the annular base portion 133R of the gasket 133. In addition, the first sealing portion 1331 and the second sealing portion 1332 of the gasket 133 are formed. Furthermore, the inner circumferential surface of the first rib 1323 is pressed outward in the second direction Dr by the first hook portion 131f via the first sealing portion 1331, and the inner circumferential surface of the rib 1323 is inclined.

[0054] Next, the second mold 300 is replaced with another third mold 400. The third mold 400 has a flat surface 400S at the center of the contact surface with the terminal board 132, and a smooth concave surface 400C that contacts the cylindrical wall portion 132W around the flat surface 400S. When the concave surface 400C of the third mold 400 is pressed against the wall portion 132W of the terminal board 132, the cylindrical wall portion 132W is bent into a flange shape to form the flange portion 1322. At that time, the third sealing portion 1333 of the gasket is formed, and the second hook portion 132f is formed on the periphery of the flange portion 1322 (FIGS. 5(g) and 5(h)). As a result, the sealing body 130 is completed (FIG. 5(i)).

[0055] Although a cylindrical electricity storage device has been described above as an example, the present disclosure can also be used for electricity storage devices of various shapes (for example, rectangular). [Industrial Applicability]

[0056] The power storage device according to the present disclosure is particularly suitable for use as a power source for vehicles such as hybrid vehicles and electric vehicles. [Explanation of symbols]

[0057] 100: Energy storage device 101:Aperture 110: Case 111:Cylinder part 112:Open end 113: Bottom 120: Electrode group 122: Lead 130: Sealing body 131: Sealing board 131A: 1st page 131B: 2nd side 131f: First hook part 131G: Second groove 1311: First recess 1311h: 1st through hole 1312: Outer periphery 1312W: Cylindrical wall 1313: 2nd Rib 132:Terminal board 132A: 3rd side 132B:Side 4 132b: Bottom 132f: Second hook part 132G: 1st groove 132W: Cylindrical wall 1321:Protrusion 1322: Flange part 1323: First Rib 1324: Second recess 133: Gasket 133h: 2nd through hole 133R: Circular base 133W: Cylindrical wall 1331: First sealing part 1332: Second sealing part 1333: Third sealing part 140: Internal insulation plate 141: Lead hole 200: First mold 201: Convex 300: 2nd mold 400: 3rd mold 400S: Flat surface 400C: Concave

Claims

1. an electrode group including a first electrode and a second electrode; a case that houses the electrode group and has an opening; and a sealing body that closes the opening of the case, The sealing body is a ring-shaped sealing plate having a first surface and a second surface opposite to the first surface, the sealing plate having a first through hole; a terminal plate having a third surface facing the first surface of the sealing plate in a first direction and a fourth surface opposite the third surface; an annular gasket interposed between the sealing plate and the terminal plate and having a second through hole overlapping with the first through hole, the sealing plate has a first recess having the first through hole and recessed in the first surface, and an outer periphery continuous with a periphery of the first recess, the terminal plate includes a protruding portion protruding from the third surface toward the sealing plate and having an end surface closing the first through hole and the second through hole, and a flange portion extending from the protruding portion in a second direction intersecting the first direction, the protruding portion of the terminal plate is received in the first recess of the sealing plate via the gasket, a peripheral edge of the outer periphery of the sealing plate and an opening end surrounding the opening of the case are joined together; the first electrode is electrically connected to the protruding portion of the terminal plate; The second electrode is electrically connected to the case. Energy storage device.

2. The first surface of the sealing plate has an inner bottom surface of the first recess and an inner circumferential surface of the first recess extending from the inner bottom surface in the first direction, The third surface of the terminal board has an end surface of the protruding portion facing the inner bottom surface and an outer circumferential surface extending in the first direction from the end surface of the protruding portion, The gasket is a first sealing portion formed around the second through hole and interposed between the end surface and the inner bottom surface; a cylindrical second sealing portion extending in the first direction from the first sealing portion and interposed between the inner peripheral surface of the first recess and the outer peripheral surface of the terminal board; and an annular third sealing portion extending from the second sealing portion in the second direction and interposed between the flange portion and the outer circumferential portion. The power storage device according to claim 1 .

3. an opening edge of the first through hole of the first recess has a first hook portion protruding so as to press the first sealing portion of the gasket; The power storage device according to claim 2 .

4. The end surface of the terminal board has a rib protruding toward the first sealing portion. The electricity storage device according to claim 3 .

5. a tip end of the first hook portion is located inward of the case in the second direction relative to the rib; The electricity storage device according to claim 4 .

6. the protruding portion has a second recess in the third surface, and the fourth surface has a first groove surrounding the second recess; The electricity storage device according to claim 5 .

7. In the first groove portion, a dimension D1 in the second direction at a position P1 is smaller than a dimension D2 in the second direction at a position P2 located on a third surface side from the position P1 in the first direction. The electricity storage device according to claim 6 .

8. An inner peripheral edge of the first sealing portion is bent toward the second recess together with the first hook portion. The electricity storage device according to claim 6 or 7.

9. The flange portion of the terminal board has a second hook portion that presses the third sealing portion. The electricity storage device according to any one of claims 2 to 8.

10. The second surface of the outer circumferential portion has a second groove portion surrounding the first recess portion. The electricity storage device according to any one of claims 1 to 9.

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