Secondary battery

Patent metadata

Field	Value
Publication number	US-2025253453-A1
Application number	US-202418794783-A
Country	US
Kind code	A1
Filing date	Aug 5, 2024
Priority date	Feb 2, 2024
Publication date	Aug 7, 2025
Grant date	—

Abstract

Disclosed is a secondary battery. The secondary battery includes an electrode assembly formed by winding a positive electrode sheet, a negative electrode sheet, and a separator interposed therebetween; a cylindrical can configured to accommodate the electrode assembly; and a cap assembly coupled to an open upper portion of the cylindrical can. The cap assembly includes a cap-up having an upwardly protruding structure, a safety vent disposed below the cap-up while surrounding an outer circumference of the cap-up, and a gasket for sealing between the cap assembly and the cylindrical can. The gasket includes a side surface surrounding outer circumferential surfaces of the cap-up and the safety vent and includes an upper portion bent inwardly to cover a peripheral upper side of the cap-up.

First claim

What is claimed is:

1 . A secondary battery comprising:
an electrode assembly comprising a positive electrode sheet, a negative electrode sheet, and a separator interposed therebetween; a cylindrical can configured to accommodate the electrode assembly; and a cap assembly coupled to an open upper portion of the cylindrical can, wherein the cap assembly comprises:
a cap-up having an upwardly protruding structure;
a safety vent disposed below the cap-up while surrounding an outer circumference of the cap-up; and
a gasket configured to provide sealing between the cap assembly and the cylindrical can, wherein the gasket comprises a side surface surrounding outer circumferential surfaces of the cap-up and the safety vent and comprises an upper portion bent inwardly to cover a peripheral upper side of the cap-up.

2 . The secondary battery as claimed in claim 1 , wherein the upper portion of the gasket is fused to the peripheral upper side of the cap-up, and wherein the side surface and a lower portion of the gasket are not fused to the cap-up.

3 . The secondary battery as claimed in claim 1 , wherein a thickness of the upper portion of the gasket is 20% or less of a thickness of the side surface of the gasket.

4 . The secondary battery as claimed in claim 1 , wherein a thickness of the upper portion of the gasket is 0.1 mm or greater and/or 1 mm or less.

5 . The secondary battery as claimed in claim 1 , wherein a thickness of the upper portion of the gasket is less than a thickness of a lower portion of the gasket.

6 . A method of manufacturing a secondary battery, the secondary battery comprising an electrode assembly formed by winding a positive electrode sheet, a negative electrode sheet, and a separator interposed therebetween; a cylindrical can configured to accommodate the electrode assembly; and a cap assembly coupled to an open upper portion of the cylindrical can, wherein the cap assembly comprises: a cap-up having an upwardly protruding structure; a safety vent disposed below the cap-up while surrounding an outer circumference of the cap-up; and a gasket configured to provide sealing between the cap assembly and the cylindrical can, and wherein the gasket comprises a side surface surrounding outer circumferential surfaces of the cap-up and the safety vent and an upper portion bent inwardly to cover a peripheral upper side of the cap-up, the method comprising:
placing the electrode assembly formed by winding the positive electrode sheet, the negative electrode sheet, and the separator interposed therebetween in the cylindrical can; preparing the cap assembly comprising the cap-up having an upwardly protruding structure, the safety vent disposed below the cap-up while surrounding an outer circumference of the cap-up, and the gasket configured to provide sealing between the cap assembly and the cylindrical can; and after the preparing of the cap assembly, coupling the cap assembly to the cylindrical can and crimping the cylindrical can, wherein the preparing of the cap assembly comprises:
placing the cap-up and the safety vent within the gasket so that the side surface of the gasket surrounds outer circumferential surfaces of the cap-up and the safety vent; and
bending the upper portion of the gasket protruding above the cap-up and the safety vent inwardly to press the safety vent surrounding an outer circumference of the cap-up and fusing the upper portion of the gasket to the cap-up, so that the cap-up and the safety vent are disposed in close contact with each other within the gasket.

7 . The method as claimed in claim 6 , wherein, in the preparing of the cap assembly, pressure fusion is performed on an entirety of a periphery of the upper portion of the gasket and the outer circumference of the cap-up.

8 . The method as claimed in claim 6 , wherein, in the preparing of the cap assembly, pressure fusion is performed on predetermined points on a periphery of the upper portion of the gasket, spaced apart from each other at regular intervals, and on the outer circumference of the cap-up.

9 . The method as claimed in claim 6 , wherein the crimping is performed such that a crimping portion of the cylindrical can is pressed inwardly to contact an upper surface of the gasket while preventing an inner surface of the crimping portion from pressing the gasket.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Kim Dae Kyu
• Kim Ji Young

Classifications

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M50/3425

  in the form of rupturable membranes or weakened parts, e.g. pierced with the aid of a sharp member · CPC title

• H01M50/167

  by crimping · CPC title

• H01M50/186

  characterised by the disposition of the sealing members · CPC title