KR-20260064103-A - BATTERY CELL

Abstract

The present invention discloses a battery cell. The battery cell of the present invention comprises: an electrode assembly having a first electrode and a second electrode; a housing having an end wall in which a terminal hole is formed and to which the first electrode is electrically connected; an electrode terminal coupled to the terminal hole and to which the second electrode is electrically connected; and a terminal gasket interposed between the electrode terminal and the end wall to electrically insulate the electrode terminal and the end wall; wherein the terminal gasket is interposed between the end wall and the electrode terminal and has a radial extension portion extending radially from the terminal hole, and the radial extension portion may be provided with a thickness reduction portion in which the thickness of the terminal gasket is reduced.

Inventors

• 임구민
• 황보광수
• 이선민
• 안성현
• 김성녕
• 진의겸

Assignees

• 주식회사 엘지에너지솔루션

Dates

Publication Date

20260507

Application Date

20241031

Claims (20)

1. An electrode assembly having a first electrode and a second electrode; A housing having an end wall in which a terminal hole is formed, and to which the first electrode is electrically connected; An electrode terminal coupled to the terminal hole and electrically connected to the second electrode; and A terminal gasket interposed between the electrode terminal and the end wall to electrically insulate the electrode terminal and the end wall; The terminal gasket is interposed between the end wall and the electrode terminal and has a radial extension extending radially from the terminal hole, and A battery cell having a thickness reduction portion in which the thickness of the terminal gasket is reduced, provided in the radiation extension portion above.
2. In paragraph 1, A battery cell having a thickness reduction portion that is recessed on the surface of the terminal gasket.
3. In paragraph 2, The above thickness reduction portion is a battery cell having a circular groove shape.
4. In paragraph 2, The above-mentioned thickness reduction portion is a battery cell having an arc-shaped groove extending in the circumferential direction.
5. In paragraph 2, A battery cell, wherein the thickness reduction portion is formed on the surface facing the electrode terminal at the radiation extension portion.
6. In paragraph 2, A battery cell, wherein the thickness reduction portion is formed on the surface of the terminal gasket in contact with the end wall.
7. In paragraph 1, A battery cell in which the surface of the terminal gasket in the thickness reduction portion contacts the electrode terminal.
8. In paragraph 1, The above thickness reduction portion is disposed in a portion of the terminal gasket in the circumferential direction, for a battery cell.
9. In paragraph 1, The above thickness reduction portion is a battery cell that is spaced apart in multiple places in a portion of the circumferential direction of the terminal gasket.
10. In paragraph 1, The above electrode terminal is a battery cell disposed in the center of the above end wall.
11. In paragraph 1, A battery cell, wherein the thickness reduction portion is disposed in a terminal gasket region that is axially compressed by the end wall and the electrode terminal.
12. In Paragraph 11, The above thickness reduction portion is a battery cell disposed on the outer surface side of the end wall at the above radiation extension portion.
13. In Paragraph 12, The above thickness reduction portion is disposed between the end wall and the head portion of the electrode terminal, in a battery cell.
14. In Paragraph 11, The above thickness reduction portion is a battery cell disposed on the inner side of the end wall.
15. In Paragraph 14, A battery cell in which the thickness reduction portion is disposed between the end wall and the shoulder portion of the electrode terminal.
16. In paragraph 1, The above thickness reduction portion is a battery cell positioned closer to the inner edge of the terminal hole in the radial direction than to the inner edge of the terminal hole of the end wall and the radial outer edge of the electrode terminal.
17. In paragraph 1, A battery cell in which the thickness of the thickness reduction portion is 0.2 to 0.8 times the thickness of the terminal gasket surrounding the thickness reduction portion.
18. In paragraph 1, A battery cell in which the gap between the end wall and the electrode terminal in the thickness reduction portion substantially corresponds to the gap between the end wall and the electrode terminal around the thickness reduction portion.
19. In paragraph 1, The above terminal gasket is, An outer radiation extension interposed between the outer surface of the end wall and the electrode terminal; An inner radiation extension interposed between the inner surface of the end wall and the electrode terminal; and A battery cell having an axial extension connecting the outer radial extension and the inner radial extension.
20. In paragraph 1, The above electrode terminal is, A head portion disposed on the outer side of the above end wall; A neck portion penetrating the terminal hole of the above end wall; and A battery cell comprising a shoulder portion disposed on the inner side of the end wall.

Description

Battery Cell The present invention relates to a battery cell in which, during thermal runaway, the terminal gasket rapidly melts and promotes electrical contact between the electrode terminal and the housing, thereby inducing fusing of the bus bar with an overcurrent. With the widespread adoption of electric vehicles, the capacity of cylindrical battery cells manufactured using cylindrical battery cans as housings is increasing. Additionally, as the size of the battery cells increases, it has become possible to place both the first electrode terminal and the second electrode terminal on the upper surface of the cylindrical battery cell. When both electrode terminals are placed on the upper surface of the battery cell, multiple cylindrical battery cells can be mounted vertically, and busbars for both electrode terminals can be placed on the upper surface of the battery cells, thereby making the structure of the vehicle battery pack simpler. The first electrode terminal of the battery cell is installed on the upper wall of the battery housing, and the second electrode terminal of the battery cell can be formed by the upper wall itself. The above battery cell has a rivet terminal installed in a terminal hole of the battery housing, and the rivet terminal and the perimeter of the terminal hole can be insulated by a terminal gasket. The primary purpose of the terminal gasket is to electrically insulate the rivet terminal from the battery housing. Multiple battery cells are accommodated in a dense manner inside the pack housing of a battery pack, and the battery cells are electrically connected to each other by busbars. If an event such as thermal runaway occurs in any of the multiple battery cells and causes ignition, the polymer synthetic resin-based electrical insulation components installed in that battery cell may be exposed to a high-temperature environment. However, during thermal runaway of a battery cell, the rivet terminal and the battery housing may not make sufficient contact, and thus a short circuit may not be induced. In this case, if the busbar connecting multiple battery cells fails to fuse due to overcurrent, the thermal runaway may spread to surrounding battery cells, potentially causing additional ignition or chain ignition. Accordingly, a technology is required to quickly induce a short circuit between the rivet terminal and the battery housing during thermal runaway of a battery cell. FIG. 1 is an exploded perspective view schematically illustrating the stacked state of electrodes and separators constituting a battery cell according to the present invention. FIG. 2 is a perspective view schematically illustrating the stacked state of the electrode and separator of FIG. 1. FIG. 3 is a perspective view schematically illustrating the state in which the electrode and separator of FIG. 1 are wound. FIG. 4 is a schematic perspective view illustrating an electrode assembly according to the present invention. FIG. 5 is a schematic perspective view illustrating the state in which a first current collector plate is welded to the cylindrical electrode assembly of FIG. 4. FIG. 6 is a schematic perspective view illustrating the state in which a second current collector plate is welded to the cylindrical electrode assembly of FIG. 4. FIG. 7 is a cross-sectional view schematically illustrating a battery cell according to the present invention. FIG. 8 is a schematic perspective view illustrating a first embodiment of a terminal gasket of a battery cell according to the present invention. FIG. 9 is a cross-sectional view schematically illustrating the terminal gasket of FIG. 8. FIG. 10 is a cross-sectional view schematically illustrating the state in which the electrode terminal and the terminal gasket are installed in the terminal hole of the battery cell of FIG. 8. FIG. 11 is a cross-sectional view schematically illustrating the compressive force, reaction force, and gas leakage possibility applied to the terminal gasket when the electrode terminal of FIG. 10 compresses the terminal gasket. FIG. 12 is a cross-sectional view schematically illustrating the gap between the outer radiating extension and the end wall when the electrode terminal of FIG. 10 compresses the terminal gasket. FIG. 13 is a cross-sectional view schematically illustrating the state in which gas pressure is applied to the end wall of the housing during thermal runaway of the battery cell of FIG. 8. FIG. 14 is an enlarged view schematically illustrating the state in which gas pressure is applied to the end wall of the housing during thermal runaway of the battery cell of FIG. 13. FIG. 15 is a schematic perspective view illustrating a second embodiment of a terminal gasket of a battery cell according to the present invention. FIG. 16 is a cross-sectional view schematically illustrating the terminal gasket of FIG. 15. FIG. 17 is a schematic perspective view illustrating a third embodiment of a terminal gasket of a battery cell according to