Search

EP-4113558-B1 - POWER STORAGE DEVICE

EP4113558B1EP 4113558 B1EP4113558 B1EP 4113558B1EP-4113558-B1

Inventors

  • SHIMIZU, KAZUMICHI
  • KOHIRA, Kazutoshi
  • GESHI, SHINYA

Dates

Publication Date
20260506
Application Date
20210219

Claims (9)

  1. A power storage device (100) comprising: an electrode group (120) including a first electrode and a second electrode; a case (110) accommodating the electrode group (120) therein, the case (110) having an opening (101); and a sealing body (130) closing the opening (101) of the case (110), wherein the sealing body (130) includes: a sealing plate (131) having a first surface (131A) and a second surface (131B) opposite to the first surface (131A), the sealing plate (131) having an annular shape having a first through-hole (1311h) provided therein; a terminal plate (132) having a third surface (132A) and a fourth surface (132B) opposite to the third surface (132A), the third surface (132A) facing the first surface (131A) of the sealing plate (131) in a first direction; and a gasket (133) disposed between the sealing plate (131) and the terminal plate (132), the gasket (133) having an annular shape having a second through-hole (133h) provided therein, the second through-hole (133h) overlapping the first through-hole (1311h), the sealing plate (131) includes a first recessed portion (1311) and an outer peripheral portion (1312) connected to a peripheral edge of the first recessed portion (1311), the first recessed portion (1311) having a recess in the first surface (131A) of the sealing plate (131) and having the first through-hole (1311h) provided therein, the terminal plate (132) includes a projecting portion (1321) projecting from the third surface (132A) toward the sealing plate (131) and a flange portion (1322) extended from the projecting portion (1321) in a second direction intersecting with the first direction, the projecting portion (1321) having an end surface closing the first through-hole (1311h) and the second through-hole (133h), the projecting portion (1321) of the terminal plate (132) is accommodated in the first recessed portion (1311) of the sealing plate (131) via the gasket (133), a peripheral edge of the outer peripheral portion (1312) of the sealing plate (131) is joined with an opening end portion (112) of the case (110) surrounding the opening (101) of the case (110), the first electrode is electrically connected to the projecting portion (1321) of the terminal plate (132), and the second electrode is electrically connected to the case (110), characterised in that an opening edge of the first through-hole (1311h) of the first recessed portion (1311) includes a first hook portion (131f) projecting so as to press a first sealing portion (1331) of the gasket (133).
  2. The power storage device (100) according to claim 1, wherein the first surface (131A) of the sealing plate (131) includes an inner bottom surface of the first recessed portion (1311) and an inner circumferential surface of the first recessed portion (1311) extended from the inner bottom surface in the first direction, the third surface (132A) of the terminal plate (132) has an end surface of the projecting portion (1321) facing the inner bottom surface and an outer circumferential surface extended from the end surface of the projecting portion (1321) in the first direction, and the gasket (133) includes: the first sealing portion (1331) provided around the second through-hole (133h) and between the end surface and the inner bottom surface; a second sealing portion (1332) provided between the inner circumferential surface of the first recessed portion (1311) and the outer circumferential surface of the terminal plate (132), the second sealing portion (1332) having a tubular shape extended from the first sealing portion (1331) in the first direction; and a third sealing portion (1333) extended from the second sealing portion (1332) in the second direction and provided between the flange portion (1322) and the outer peripheral portion (1312), the third sealing portion (1333) having an annular shape.
  3. The power storage device (100) according to claim 1 or 2, wherein the end surface of the terminal plate (132) includes a rib projecting toward the first sealing portion (1331).
  4. The power storage device (100) according to claim 3, wherein a tip end of the first hook portion (131f) is located in an inner side of the case (110) with respect to the rib in the second direction.
  5. The power storage device (100) according to claim 4, wherein the projecting portion (1321) includes a second recessed portion (1324) having a recess in the third surface (132A) and a first groove portion (132G) provided in the fourth surface (132B), the first groove portion (132G) surrounding the second recessed portion (1324).
  6. The power storage device (100) according to claim 5, wherein a dimension D1 of the first groove portion (132G) at a position P1 in the second direction is smaller than a dimension D2 of the first groove portion (132G) at a position P2 which is closer to the third surface (132A) than the position P1 in the first direction.
  7. The power storage device (100) according to claim 5 or 6, wherein an inner circumferential edge of the first sealing portion (1331) is bent toward the second recessed portion (1324) together with the first hook portion (131f).
  8. The power storage device (100) according to any one of claims 1 to 7, wherein the flange portion (1322) of the terminal plate (132) includes a second hook portion (132f) pressing the third sealing portion (1333).
  9. The power storage device (100) according to any one of claims 1 to 8, wherein the second surface (131B) of the outer peripheral portion (1312) includes a second groove portion (131G) surrounding the first recessed portion (1311).

Description

TECHNICAL FIELD The present disclosure relates to a power storage device. BACKGROUND ART The document US 2018/205044 discloses a sealing body of a tube-shaped battery, the document EP 0 959 508 discloses a current interrupt apparatus, the document US 2015/155532 discloses a battery, the document WO 2018/159180 discloses a secondary battery and the document EP 1 018 175 discloses a current interrupter for electrochemical cells. A power storage device is widely used as a driving source of a vehicle, an electronic device, or the like. Typically, the power storage device includes a case accommodating an electrode group including a first electrode and a second electrode and has an opening, and a sealing body closing the opening of the case. In the case that the first electrode is electrically connected to the case, the second electrode is connected to a terminal portion provided in the sealing body. The terminal portion is insulated electrically from the case. PTL 1 discloses a nonaqueous electrolyte secondary battery including a battery case with a bottomed tubular shape, a power generation element accommodated in the battery case, and a sealing plate closing an opening of the battery case. The sealing plate includes a flange portion, a boss portion, and a projecting portion. The flange portion is formed so as to substantially coincide with the shape of an opening of the battery case. The boss portion holds a gas discharger configured to break when a pressure inside the battery case reaches a predetermined value. The projecting portion projects to the inside of the boss portion. A cap serving as one electrode terminal, an upper metal thin plate, a lower metal thin plate, and a gasket are disposed between the projecting portion and a bending portion of the boss portion which is formed such that one end of the boss portion is bent inward. Citation List Patent Literature PTL 1: Japanese Patent Laid-Open Publication No. 2004- 241171 SUMMARY OF THE INVENTION TECHNICAL PROBLEM For providing the above-mentioned boss portion and projecting portion on the sealing plate of Patent Literature 1, however, complicated processing is required. For instance, one of the boss portion and the projecting portion is formed on the sealing plate, the other is needed to be formed on the sealing plate by welding or forging. To manufacture such a sealing plate accurately, a high cost is needed. For that reason, the present disclosure aims to provide a power storage device including a sealing body processed easily. SOLUTION TO PROBLEM The problem is solved by a power storage device according to claim 1. Further advantageous embodiments are featured in the dependent claims. ADVANTAGEOUS EFFECT OF INVENTION According to the present disclosure, sealing between the sealing plate and the terminal plate can be performed without the projecting portion. This provides a power storage device including a sealing body formed easily. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a cross-sectional view of an example of a power storage device in accordance with one exemplarily embodiment of the present disclosure.FIG. 2 is a cross-sectional view of a modification of the power storage device in accordance with the exemplarily embodiment of the present disclosure.FIG. 3A is a cross-sectional view of a modification of a sealing body in accordance with the exemplarily embodiment of the present disclosure.FIG. 3B is a cross-sectional view of a main part of another modification of the sealing body in accordance with the exemplarily embodiment of the present disclosure.FIG. 4 is a process chart showing a manufacturing process (first half) of the sealing body in accordance with one exemplarily embodiment of the present disclosure.FIG. 5 is a process chart showing a manufacturing process (latter half) of the sealing body in accordance with one exemplarily embodiment of the present disclosure. DESCRIPTION OF EMBODIMENTS A power storage device in accordance with one aspect of the present disclosure includes an electrode group including a first electrode and a second electrode, a case accommodating the electrode group and having an opening, and a sealing body closing the opening of the case. The case has a cylindrical shape, for example. The case has, for example, a tubular portion, an opening end portion connected to one end of the tubular portion and corresponding to the opening, a bottom closing the other end of the tubular portion. The case has conductivity. The case is made of metal, for example. The metal constituting the case may be aluminum, copper, iron, stainless steel, nickel, alloy combined by these metals, and the like. In the electrode group, the first electrode and the second electrode are wound via a separator between the electrodes, for example. If the power 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. The sealing body includes: a sealing plate with an ann