Secondary battery and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-9620746-B2
Application number	US-201514639903-A
Country	US
Kind code	B2
Filing date	Mar 5, 2015
Priority date	May 15, 2014
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

A method of manufacturing a secondary battery, which is capable of simplifying a processing method. The method includes preparing a cap plate that closes an opening of a case, the case accommodating an electrode assembly therein and having the opening at an end thereof, forming a short-circuit portion and a vent portion on the cap plate, performing a first heat treatment on the short-circuit portion, and performing a second heat treatment on the vent portion. The secondary battery manufactured by this method is economical because the processing method is simplified and a manufacturing cost is reduced.

First claim

What is claimed is:

1. A secondary battery, comprising:
an electrode assembly having a first electrode plate, a second electrode plate, and a separator between the first electrode plate and the second electrode plate;
a case accommodating the electrode assembly therein, the case having an opening at an end thereof; and
a cap plate closing the opening of the case, with a vent portion and a short-circuit portion formed in set portions of the cap plate,
wherein the vent portion and the short-circuit portion are integrated with the cap plate.

2. The secondary battery of claim 1 , wherein a grain size of each of the vent portion and the short-circuit portion is larger than that of a remaining portion of the cap plate except the vent portion and the short-circuit portion.

3. The secondary battery of claim 1 , wherein the vent portion and the short-circuit portion are lower in hardness than a remaining portion of the cap plate except the vent portion and the short-circuit portion.

4. The secondary battery of claim 3 , wherein the short-circuit portion has a hardness of 3 to 5 kgf/cm 2 .

5. The secondary battery of claim 3 , wherein the vent portion has a hardness of 6 to 8 kgf/cm 2 .

6. The secondary battery of claim 1 , wherein the vent portion and the short-circuit portion are formed by machining the cap plate and then performing a heat treatment.

7. The secondary battery of claim 6 , wherein the heat treatment is performed by an induction heating apparatus.

8. The secondary battery of claim 6 , wherein the heat treatment is performed only at the set portions of the cap plate.

9. A method of manufacturing a secondary battery, comprising:
preparing a cap plate that closes an opening of a case, the case accommodating an electrode assembly therein and having the opening at an end thereof;
forming a short-circuit portion and a vent portion on the cap plate;
performing a first heat treatment on the short-circuit portion; and
performing a second heat treatment on the vent portion.

10. The method of claim 9 , wherein the short-circuit portion and the vent portion are formed by a process selected out from a group consisting of casting, forging, rolling and pressing.

11. The method of claim 9 , wherein the first heat treatment and the second heat treatment are performed by an induction heating apparatus.

12. The method of claim 11 , wherein the first heat treatment is performed for 70 minutes or less at a temperature of 400° C. to 500° C.

13. The method of claim 11 , wherein the second heat treatment is performed for 70 minutes or less at a temperature of 200° C. to 300° C.

14. The method of claim 9 , wherein the first treatment and the second heat treatment are only performed on the short-circuit portion and the vent portion, respectively.

15. The method of claim 9 , wherein the first heat treatment is performed before the second heat treatment.

16. The method of claim 9 , wherein the first heat treatment is performed after the second heat treatment.

17. The method of claim 9 , wherein the first heat treatment is performed concurrently with the second heat treatment.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Kim Ki Hyun

Classifications

• H01M50/30 Primary

  Arrangements for facilitating escape of gases · CPC title

• Y10T29/4911

  including sealing · CPC title

• H01M50/591

  Covers · CPC title

• H01M50/147

  Lids or covers · CPC title

• H01M10/058 Primary

  Construction or manufacture · CPC title