KR-20260064104-A - BATTERY CELL

Abstract

The present invention provides a battery cell having a structure that prevents external short circuits of other battery cells by rapidly melting a terminal gasket during thermal runaway or venting of the battery cell, thereby bringing the electrode terminal and the housing into contact and electrically connecting them, and causing other battery cells connected to them via a busbar to short-circuit through the connection portion, thereby fusing the busbar with an overcurrent. The terminal gasket is interposed between the end wall and the electrode terminal and has a radially extended portion, and a conductor is inserted into the radially extended portion.

Inventors

• 임구민
• 황보광수
• 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 portion that extends in a radial direction, and A battery cell with a conductor inserted in the above-mentioned radiation extension.
2. In paragraph 1, The above conductor is a battery cell embedded inside the radiation extension or exposed on the surface of the radiation extension.
3. In paragraph 1, The above conductor is a battery cell inserted into a groove formed on the surface of a terminal gasket.
4. In paragraph 1, The above terminal gasket is a battery cell formed by insert injection molding the conductor into a resin.
5. In paragraph 1, A battery cell in which the surface of the conductor contacts either of the end wall and the electrode terminal.
6. In paragraph 1, The above conductor is a battery cell disposed in a portion of the circumferential direction of the terminal gasket.
7. In paragraph 6, The above conductor is a battery cell spaced apart in a portion of the circumferential direction of the terminal gasket.
8. In paragraph 6, The above conductor is a battery cell having a disk shape of a predetermined thickness.
9. In paragraph 1, The above conductor is a battery cell disposed over the entire area in the circumferential direction of the terminal gasket.
10. In Paragraph 9, The above conductor is a battery cell having a ring shape of a predetermined thickness.
11. In paragraph 1, The above electrode terminal is a battery cell installed in the center of the above end wall.
12. In paragraph 1, The above conductor is a battery cell disposed in an area that is axially compressed by the end wall and the electrode terminal in the terminal gasket.
13. In paragraph 1, The above conductor is a battery cell disposed on the outer side of the end wall.
14. In Paragraph 13, The above conductor is a battery cell disposed between the end wall and the head portion of the electrode terminal.
15. In paragraph 1, The above conductor is a battery cell disposed on the inner side of the end wall.
16. In paragraph 15, The above conductor is a battery cell disposed between the end wall and the shoulder portion of the electrode terminal.
17. In paragraph 1, The above conductor is a battery cell positioned closer in the radial direction to the inner edge of the terminal hole among the radial inner edge of the end wall defined by the terminal hole of the end wall and the radial outer edge of the electrode terminal.
18. In paragraph 1, A battery cell in which the thickness of the conductor measured in the compression direction is 0.1 to 0.3 times the axial distance between the end wall region and the electrode terminal region facing the conductor in the axial direction.
19. In paragraph 1, A battery cell in which the first thickness of the terminal gasket region into which the conductor is inserted is thinner than the second thickness of the terminal gasket surrounding it.
20. In paragraph 1, A battery cell in which the first thickness is 0.7 to 0.9 times the second thickness.

Description

Battery Cell The present invention relates to a battery cell capable of fusing a busbar through an external short circuit during thermal runaway. More specifically, the invention relates to a battery cell having a structure that prevents external short circuits of other battery cells by rapidly melting a terminal gasket during thermal runaway or venting of the battery cell, thereby bringing the electrode terminal and the housing into contact and electrically connecting them, and causing other battery cells connected to them through a bus bar to short-circuit through the connection part, and thereby causing the bus bar to be fused 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 of the above type are housed in a dense configuration inside the pack housing of a battery pack, and these battery cells are electrically interconnected by busbars. If an event such as thermal runaway occurs in any of the multiple battery cells within the battery pack and causes ignition, the electrical insulation components made of polymer synthetic resins installed in that battery cell may be exposed to a high-temperature environment. In order to prevent the battery cell where the event occurred from affecting other battery cells, a so-called internal short-circuit prevention structure may be applied to the battery cell to prevent the two electrodes of the electrode assembly of the battery cell where the event occurred from being short-circuited. Meanwhile, since the first and second electrode terminals of the battery cell where the event occurred are electrically connected to other battery cells via a busbar, if a short circuit occurs between the first and second electrode terminals, other battery cells are short-circuited externally, that is, by the battery cell where the event occurred. Therefore, to prevent this phenomenon, a so-called external short-circuit prevention structure is required for the 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 gap between the outer radiating extension and the end wall when the electrode terminal of FIG. 10 compresses the terminal gasket. FIG. 12 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. 13 is a cross-sectional view schematically illustrating the