Battery case for secondary battery

Patent metadata

Field	Value
Publication number	US-9531032-B2
Application number	US-201414315006-A
Country	US
Kind code	B2
Filing date	Jun 25, 2014
Priority date	Mar 23, 2012
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

Disclosed herein is a battery case including a receiving part having an electrode assembly mounted therein, wherein the receiving part, which is formed by deforming a sheet type base material, is configured to have a stair-like structure in which at least one corner and/or surface forming a shape of the receiving part is deformed.

First claim

The invention claimed is:

1. A method of manufacturing a battery cell having an electrode assembly mounted in a battery case having a receiving part including an electrode assembly mounted therein, wherein the receiving part, which is formed by deforming a sheet type base material, is configured to have a stair structure in which at least one corner and/or surface forming a shape of the receiving part is deformed, the method comprising:
(a) placing the sheet type base material on a die having a groove;
(b) pressing the sheet type base material into the groove of the die using a punch, an outside of which is configured to have an asymmetric structure, such that wrinkles and chlorosis do not occur at corners of a receiving part formed from the sheet type base material;
(c) mounting the electrode assembly in the receiving part; and
(d) placing a cover on the receiving part to seal the receiving part, wherein
the groove of the die is formed in a shape corresponding to that of an outside of the punch such that the sheet type base material coincides with the shape of the outside of the punch when the sheet type base material contacts the punch and the groove of the die,
the punch comprises two or more punches having different widths and heights, the die is provided at an inside thereof with a stair structure comprising steps formed in shapes corresponding to the respective punches, and the stair structure of the receiving part is formed by the punch and the die,
the stair structure of the receiving part is formed by pressing performed using one of the punches having largest width and then by pressing performed using the punches having next largest widths,
a pressed depth of the sheet type base material is decreased as the sheet type base material is pressed using the punches in order of decreasing width,
the receiving part has a side wall configured to have the stair structure including two or more steps and the steps have heights gradually decreased in a depth direction of the receiving part,
the die is provided with a depressed part configured to have the stair structure comprising an upper step, a middle step, and a lower step,
the two or more punches comprise a first punch corresponding to a shape of the upper step of the die, a second punch corresponding to a shape of the middle step of the die, and a third punch corresponding to a shape of the lower step of the die,
the second punch is formed in a shape corresponding to the shapes of the upper step and the middle step of the die,
the third punch is formed in a shape corresponding to the shapes of the upper step, the middle step, and the lower step of the die, and
step (b) further comprises:
(i) pressing the sheet type base material using the first punch to transfer the shape of the upper step of the die to the sheet type base material;
(ii) pressing the sheet type base material using the second punch to transfer the shapes of the upper step and the middle step of the die to the sheet type base material; and
(iii) pressing the sheet type base material using the third punch to transfer the shapes of the upper step, the middle step, and the lower step of the die to the sheet type base material.

2. The method according to claim 1 , wherein a stair structure is formed at a bottom of the punch.

3. The method according to claim 2 , wherein the stair structure is formed at a middle, one side, or one corner of the bottom of the punch.

4. The method according to claim 1 , further comprising forming a vacuum in a space defined between the die and the sheet type base material such that the sheet type base material comes into tight contact with the groove of the die.

5. The method according to claim 1 , further comprising forming a vacuum in a space defined between the die and the sheet type base material such that the sheet type base material comes into tight contact with the groove of the die.

6. The method according to claim 1 , wherein corners of an outside of the punch and corners of an inside of the die are rounded.

7. The method according to claim 1 , wherein, in a case in which the number of the punches is n, the pressed depth of the sheet type base material formed by the n-th punch is equivalent to 60 to 90% of that of the sheet type base material formed by the (n−1) th punch.

8. The method according to claim 7 , wherein corners of outsides of the punches and corners of an inside of the die are rounded.

Assignees

• Lg Chemical Ltd

Inventors

• Kim Young Hoon
• Kwon Sungjin
• Kim Dong-Myung
• Kim Ki Woong
• Park Hyun
• Ahn Soonho

Classifications

• H01M10/0436 Primary

  Small-sized flat cells or batteries for portable equipment · CPC title

• H01M10/052

  Li-accumulators · CPC title

• B21D22/02

  Stamping using rigid devices or tools · CPC title

• Y10T29/49108

  Electric battery cell making · CPC title

• H01M50/105 Primary

  Pouches or flexible bags · CPC title