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KR-102963342-B1 - secondary battery

KR102963342B1KR 102963342 B1KR102963342 B1KR 102963342B1KR-102963342-B1

Abstract

The present invention relates to a secondary battery that reduces the overall resistance of the secondary battery, improves space utilization, and allows for easy injection of an electrolyte. A secondary battery according to an embodiment of the present invention comprises a case, an electrode assembly, and a cap assembly. An opening is formed in the case. The electrode assembly is inserted into the case through the opening and is provided with an electrode portion and a plurality of foil tabs formed on the electrode portion. The cap assembly seals the opening of the case into which the electrode assembly is inserted. The cap assembly includes a cap plate, an upper gasket, an insulating plate, an electrode terminal, and a current collector. A through hole is formed in the cap plate. The insulating plate is positioned below the cap plate, and the upper gasket is positioned above the cap plate. An electrode terminal is positioned above the upper gasket, and an insertion hole is formed therein. The current collector comprises a current collector plate and a current collector projection formed on the upper surface of the current collector plate, inserted into the insertion hole, and welded to the upper end of the electrode terminal.

Inventors

  • 이현희

Assignees

  • 주식회사 엘지에너지솔루션

Dates

Publication Date
20260511
Application Date
20250402
Priority Date
20240819

Claims (20)

  1. A case with an opening formed therein; An electrode assembly inserted into the case through the opening and having an electrode portion and a plurality of foil tabs formed on the electrode portion; and A cap assembly that seals the opening of the case into which the electrode assembly is inserted; is included. The above cap assembly is Cap plate with a through hole formed therein; An upper gasket disposed on the upper part of the above cap plate; An insulating plate disposed below the above cap plate; An electrode terminal disposed on the upper gasket and having an insertion hole formed therein; A current collecting member having a current collecting plate and a current collecting projection formed on the upper surface of the current collecting plate, inserted into the insertion hole, and welded to the upper end of the electrode terminal; and A sealing gasket interposed between the through hole and the current collecting projection; comprising The above-mentioned current collecting protrusion includes a first current collecting protrusion formed on the upper surface of the current collecting plate and having a first diameter, and a second current collecting protrusion formed on the upper surface of the first current collecting protrusion and having a second diameter smaller than the first diameter. A secondary battery characterized in that the step created by the first current collecting protrusion and the second current collecting protrusion engages with the step created by the sealing gasket and the lower surface of the electrode terminal.
  2. In Article 1, A secondary battery characterized in that the above current collector plate is positioned to be in contact with the lower surface of the sealing gasket and the insulating plate.
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  5. In Article 1, A secondary battery characterized by having a groove formed on the upper surface of the second current collector projection.
  6. In Article 5, A secondary battery characterized in that the above-mentioned groove is formed in a truncated cone shape or a hemispherical shape.
  7. In Article 1, A secondary battery characterized in that the above-mentioned cap plate has a seating surface formed around the through hole and a stepped surface protruding from the outside of the seating surface, and the upper gasket is interposed between the cap plate and the electrode terminal.
  8. In Article 7, The upper gasket above A first horizontal surface formed with a first thickness and formed to be in contact with the seating surface of the cap plate, and A second horizontal surface formed with a second thickness thicker than the first thickness and formed to be in contact with the seating surface and the stepped surface, and A secondary battery characterized by including a vertical plane that extends vertically from the outer end of the second horizontal plane and surrounds the outer surface of the electrode terminal.
  9. In Article 2, A secondary battery characterized in that a first alignment projection is formed on the lower surface of the through hole side of the cap plate in a shape connected to the through hole, and a first alignment groove is formed on the sealing gasket at a position corresponding to the first alignment projection.
  10. In Article 2, A secondary battery characterized in that a second alignment projection is formed on the upper surface of the current collector plate, and a second alignment groove is formed on the lower surface of the sealing gasket at a position corresponding to the second alignment projection.
  11. In Article 1, A secondary battery characterized in that a fitting groove is formed on the lower surface of the electrode terminal, and a fitting projection that fits into the fitting groove is formed on the upper surface of the first current collecting projection.
  12. In Article 11, The above-mentioned fitting groove is formed in the stepped portion created by the first current collecting projection and the second current collecting projection, and A secondary battery characterized in that the above-mentioned fitting projection is formed at a position corresponding to the fitting groove on the upper surface of the first current collecting projection located on the outer side of the second current collecting projection.
  13. In Article 1, A secondary battery characterized in that a first undercut is formed at the bottom of the sealing gasket, and a first inclined surface having a shape corresponding to the first undercut is formed at the bottom of the first current collecting projection.
  14. A case with an opening formed therein; An electrode assembly inserted into the case through the opening and having an electrode portion and a plurality of foil tabs formed on the electrode portion; and A cap assembly that seals the opening of the case into which the electrode assembly is inserted; is included. The above cap assembly is Cap plate with a through hole formed therein; An upper gasket disposed on the upper part of the above cap plate; An insulating plate disposed below the above cap plate; An electrode terminal disposed on the upper gasket and having an insertion hole formed therein; A current collecting member having a current collecting plate and a current collecting projection formed on the upper surface of the current collecting plate, inserted into the insertion hole, and welded to the upper end of the electrode terminal; and A sealing gasket interposed between the through hole and the current collecting projection; comprising The above-mentioned current collecting protrusion includes a first current collecting protrusion formed on the upper surface of the current collecting plate and having a first diameter, and a second current collecting protrusion formed on the upper surface of the first current collecting protrusion and having a second diameter smaller than the first diameter. A secondary battery characterized in that a second undercut is formed on the lower surface of the insertion hole side of the electrode terminal, and a second inclined surface having a shape corresponding to the second undercut is formed on the lower surface of the second current collecting projection.
  15. In Article 1, A secondary battery characterized in that the above-mentioned current collecting protrusion is formed in the center of the upper surface of the current collecting plate, and an adhesive layer including a heat-fusion layer is formed on both sides of the upper surface of the current collecting plate.
  16. In Article 1, It includes an insulating member disposed between the above-mentioned cap plate and the above-mentioned electrode assembly and having the above-mentioned insulating plate, and A secondary battery characterized in that the insulating member comprises a guide hole located below an electrolyte injection port formed in the cap plate and a guide portion protruding downward from the guide hole to guide the movement of the electrolyte.
  17. In Article 16, A secondary battery characterized by the above guide portion including a support located at the lower part of the guide hole that partially blocks the guide hole, and an internal hole formed in the support that moves fluid.
  18. In Article 17, A secondary battery characterized in that the guide portion includes a guide rim that surrounds the lower part of the guide hole, the support member is fixed to the guide rim, and a first opening and a second opening are formed between the side end of the support member and the inner wall of the guide rim.
  19. In Article 16, A vent portion for discharging gas is formed in the above cap plate, and The above insulating member includes an exhaust section that protrudes toward the bottom of the case and has a plurality of exhaust openings, and A secondary battery characterized in that the exhaust portion is located below the vent portion.
  20. In Article 1, A secondary battery characterized in that the plurality of foil tabs are formed in one direction of the electrode assembly.

Description

secondary battery The present invention relates to a secondary battery. Secondary batteries, which possess electrical characteristics such as high energy density and high applicability across product categories, are widely applied not only to portable devices but also to electric vehicles (EVs) and hybrid electric vehicles (HEVs) driven by electric power sources. These secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency, as they not only have the primary advantage of being able to drastically reduce the use of fossil fuels but also the advantage of not generating any by-products from the use of energy. Currently, widely used types of secondary batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells is approximately 2.5V to 4.5V. Secondary batteries can be classified according to the shape of the battery case into can-type secondary batteries, in which the electrode assembly is embedded in a metal can, and pouch-type secondary batteries, in which the electrode assembly is embedded in a pouch of aluminum laminate sheet. Can-type secondary batteries can be classified into cylindrical secondary batteries and prismatic secondary batteries depending on the shape of the metal can. In a prismatic secondary battery, an electrode assembly is housed within a metal case, and a cap member is attached to the open end. Conventional cap members use rivets to connect the electrode terminals and the cap plate, which increases the number of parts and consequently raises the overall resistance of the secondary battery, while the rivets cause a problem of reduced space utilization. In addition, prismatic batteries are equipped with an electrolyte injection port; however, if the electrolyte injection port is blocked by foreign substances or internal components, problems such as reduced electrolyte injection speed or backflow of electrolyte may occur. FIG. 1 is a perspective view showing a secondary battery according to one embodiment of the present invention. Figure 2 is a cross-sectional view taken along line AA in Figure 1. FIG. 3 is an exploded perspective view of a secondary battery according to one embodiment of the present invention. FIG. 4 is a perspective view showing an electrode assembly having a plurality of first and second foil tabs formed on an electrode portion in a secondary battery according to one embodiment of the present invention. FIG. 5 is a drawing showing a first electrode plate and a second electrode plate in a secondary battery according to one embodiment of the present invention. FIG. 6 is an exploded perspective view of a secondary battery according to another embodiment of the present invention. FIG. 7 is a perspective view showing an electrode assembly having a plurality of first and second foil tabs formed on an electrode portion in a secondary battery according to another embodiment of the present invention. FIGS. 8 and 9 are drawings showing a first electrode plate and a second electrode plate in a secondary battery according to an embodiment of the present invention. FIG. 10 is a perspective view showing a cap assembly according to a first embodiment of the present invention. FIG. 11 is a cross-sectional view showing a cap assembly according to a first embodiment of the present invention. FIG. 12 is a cross-sectional view showing a cap assembly according to a second embodiment of the present invention. FIG. 13 is a cross-sectional view showing a cap assembly according to a third embodiment of the present invention. FIG. 14 is a cross-sectional view showing a cap assembly according to a fourth embodiment of the present invention. FIG. 15 is a top perspective view of an insulating member of a secondary battery according to embodiments of the present invention. FIG. 16 is a perspective view from below of an insulating member of a secondary battery according to embodiments of the present invention. FIG. 17 is a bottom view of an insulating member of a secondary battery according to embodiments of the present invention. FIG. 18 is a partial cross-sectional view illustrating a cap plate and an insulating member. FIG. 19 is a cutaway perspective view illustrating one embodiment of a guide portion of an insulating member. FIG. 20 is a cross-sectional view illustrating another embodiment of the guide portion of the insulating member. FIG. 21 is a cross-sectional view illustrating the exhaust portion of an insulating member. FIG. 22 is a drawing illustrating the process of combining a foil tab and a current collector in a secondary battery according to one embodiment of the present invention. FIG. 23 is a drawing illustrating the process of combining a cap member and a current collector member in a secondary battery according to one embodiment of the present invention. FIG. 24 is a drawin