Secondary Battery and Battery Pack Including the Same

Patent metadata

Field	Value
Publication number	US-2021167460-A1
Application number	US-202017254584-A
Country	US
Kind code	A1
Filing date	Apr 8, 2020
Priority date	Jun 4, 2019
Publication date	Jun 3, 2021
Grant date	—

Abstract

According to one aspect of the present invention, the secondary battery includes: a waterproof part configured to surround at least a portion of a circumference of the electrode assembly so that a gas within the exterior passes through the waterproof part, but a liquid within the exterior does not pass through the waterproof part; and a vent part provided in an inner surface of the exterior to provide a path through which the gas within the exterior is discharged to the outside when an internal pressure of the exterior exceeds a certain value.

First claim

1 . A secondary battery comprising:
an electrode assembly having a structure in which electrodes and separators are alternately disposed; an exterior having an inner space in which the electrode assembly is accommodated; a waterproof part provided within the exterior to surround at least a portion of a circumference of the electrode assembly and configured to allow a gas to pass through the waterproof part, but prevent a liquid from passing through the waterproof part; and a vent part provided at a first portion of the exterior to provide a path through which gas within the exterior is discharged to an outside when an internal pressure of the exterior exceeds a predetermined value.

2 . The secondary battery of claim 1 , wherein the exterior comprises two sheets that face each other,
each of the two sheets having a circumferential part, wherein a first portion of the circumferential part extends away from the first portion of the exterior at which the vent part is provided.

3 . The secondary battery of claim 1 , further comprising an electrode lead protruding outward from a second portion of the exterior different from the first portion of the exterior at which the vent is provided.

4 . The secondary battery of claim 1 , wherein the waterproof part surrounds an entire circumference of the electrode assembly.

5 . The secondary battery of claim 2 , wherein the vent part comprises a first vent member and a second vent member, which face each other, and
a distance between the first vent member and the second vent member decreases in an outward direction of the exterior.

6 . The secondary battery of claim 5 , wherein one end of the first vent member and one end of the second vent member, which extend in the outward direction, contact each other to block the path through which the gas within the exterior is discharged to the outside, and
when the internal pressure of the exterior exceeds the predetermined value, the one end of the first vent member and the one end of the second vent member are spaced apart from each other to provide the path through which the gas within the exterior is discharged to the outside.

7 . The secondary battery of claim 5 , further comprising an elastic part provided between an inner surface of the circumferential part and the vent part to press the vent part by elastic force.

8 . The secondary battery of claim 7 , wherein the elastic part comprises:
a first elastic member provided between the inner surface of the circumferential part and the first vent member to press the first vent member by the elastic force; and a second elastic member provided between the inner surface of the circumferential part and the second vent member to press the second vent member by the elastic force.

9 . The secondary battery of claim 6 , wherein, when the internal pressure of the exterior decreases below the predetermined value, the one end of the first vent member and the one end of the second vent member contact each other to block the path through which the gas within the exterior is discharged to the outside.

10 . The secondary battery of claim 2 , wherein a second portion of the circumferential part of the two sheets are bonded to each other to provide a sealing part, and
the first portion of the two sheets of the circumferential part are not bonded to each other or are bonded to each other with a bonding force that is less than that of the sealing part on the second portion of the circumferential part of the two sheets.

11 . A battery pack comprising the secondary battery of claim 1 .

12 . The battery pack of claim 11 , wherein the exterior comprises two sheets that face each other,
each of the two sheets having a circumferential part wherein a first portion of the circumferential part extends away from the first portion of the exterior at which the vent part is provided.

Assignees

• Lg Chemical Ltd

Inventors

• Park Min Hee
• Park Sang Jun

Classifications

• H01M50/392

  with means for neutralising or absorbing electrolyte; with means for preventing leakage of electrolyte through vent holes · CPC title

• H01M10/0566

  Liquid materials · CPC title

• H01M50/136 Primary

  Flexibility or foldability · CPC title

• H01M50/367

  Internal gas exhaust passages forming part of the battery cover or case; Double cover vent systems · CPC title

• Y02P70/50

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