Secondary Battery and Manufacturing Method of the Same

Abstract

A secondary battery according to an embodiment of the present disclosure includes an electrode assembly, a battery case that houses the electrode assembly and has an opened upper party, and a cap assembly that is coupled to the opened upper part of the battery case.The cap assembly comprises a safety vent formed with a notch portion, and a gap formed by the notch portion is closed.

Description

Claims

1. A secondary battery comprising: an electrode assembly;a battery case that houses the electrode assembly and has an opened upper part; anda cap assembly that is coupled to the opened upper part of the battery case,wherein the cap assembly comprises a safety vent formed with a notch portion, andwherein a gap formed by the notch portion is closed.

2. The secondary battery of claim 1, wherein: the safety vent is exposed to the outside from an opened upper part of the battery case.

3. The secondary battery of claim 1, wherein: the safety vent is a disk-shaped plate, andthe notch portion is shaped to define a recessed groove in the safety vent extending along a circular path.

4. The secondary battery of claim 1, wherein: one end of the opened upper part of the battery case is bent to wrap around a portion of the cap assembly and form a crimping portion.

5. The secondary battery of claim 4, wherein: the crimping portion of the battery case wraps around an outer peripheral part of the safety vent.

6. The secondary battery of claim 5, wherein: the safety vent comprises a curling portion bent at the outer peripheral part of the safety vent, andthe crimping portion wraps around the curling portion to form a crimping joint.

7. The secondary battery of claim 1, wherein: the safety vent is formed with a bent portion bent away from the electrode assembly.

8. A manufacturing method of a secondary battery, the manufacturing method comprising the steps of: manufacturing a safety vent;manufacturing a cap assembly including the safety vent;housing the electrode assembly in a battery case having an opened upper part; andjoining the cap assembly to the opened upper part of the battery case,wherein the step of manufacturing the safety vent comprises forming a notch portion on one surface of a metal plate material, andclosing a gap formed by the notch portion.

9. The manufacturing method of a secondary battery of claim 8, wherein: the safety vent is exposed to the outside from the-an opened upper part of the battery case.

10. The manufacturing method of a secondary battery of claim 8, wherein: the safety vent is a disk-shaped plate, andthe notch portion is shaped to define a recessed groove in the safety vent extending along a circular path.

11. The manufacturing method of a secondary battery of claim 8, wherein: the step of manufacturing the safety vent further comprises bending the flange part formed on the metal plate material to form a curling portion, andthe step of joining the cap assembly further comprises bending one end of the opened upper part of the battery case to form a crimping portion that wraps around the cap assembly and the curling portion.

12. The manufacturing method of a secondary battery of claim 8, wherein: the step of closing the gap formed by the notch portion includes a forging step performed on a first portion and a second portion of the safety vent on each side of the gap.