Battery Case For Secondary Battery And Method For Manufacturing Pouch Type Secondary Battery

Patent metadata

Field	Value
Publication number	US-2022255186-A1
Application number	US-202017626895-A
Country	US
Kind code	A1
Filing date	Aug 25, 2020
Priority date	Aug 27, 2019
Publication date	Aug 11, 2022
Grant date	—

Abstract

A battery case for a secondary battery according to an embodiment of the present invention can include a cup part having an accommodation space configured to accommodate an electrode assembly in which electrodes and separators are stacked; a sealing part extending to the outside of the cup part; a gas discharge part attached to a hole which is formed to be punched in at least one of the cup part or the sealing part from the outside and through which a gas passes; and a coating part applied to an inner circumferential surface of the hole and having electrolyte resistance, wherein the gas discharge part includes: a gas discharge layer through which the gas passes; and an outer functional layer formed on an outer surface of the gas discharge layer and having a hydrophobic property.

First claim

1 . A battery case for a secondary battery, comprising
a cup part having an accommodation space configured to accommodate an electrode assembly, the electrode assembly including electrodes and separators; a sealing part extending to the outside of the cup part; a gas discharge part attached to a hole, the hole formed through at least one of the cup part or the sealing part, the hole configured to allow a gas to pass therethrough; and a coating part applied to an inner circumferential surface of the hole and having electrolyte resistance, wherein the gas discharge part comprises:
a gas discharge layer configured to allow the gas to pass therethrough; and
an outer functional layer formed on an outer surface of the gas discharge layer, the outer functional layer being hydrophobic.

2 . The battery case of claim 1 , wherein the coating part comprises at least one of at least one of polypropylene (PP), polyethylene (PE), or epoxy.

3 . The battery case of claim 1 , wherein the outer functional layer is formed by distributing a plurality of protrusions on an outer surface thereof.

4 . The battery case of claim 3 , wherein each of the protrusions have a diameter of 50 nm to 10 μm.

5 . The battery case of claim 4 , wherein each of the protrusions have a diameter of 100 nm to 1 μm.

6 . The battery case of claim 1 , wherein an inner functional layer of the gas discharge part comprises an oil or wax component.

7 . The battery case of claim 6 , wherein the oil comprises at least one of fluorinated carbon oil, silicone oil, carbon-based oil, or fatty acid amide.

8 . The battery case of claim 1 , wherein the gas discharge layer comprises at least one of polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), or polyvinylidene fluoride (PVDF).

9 . The battery case of claim 1 , wherein the gas discharge part further comprises an inner functional layer formed on an inner surface of the gas discharge layer, the inner functional layer being hydrophobic.

10 . The battery case of claim 1 , wherein the sealing part comprises:
an inner area adjacent to the cup part; and an outer area disposed outside the inner area to provide an edge of the sealing part, the outer area configured to form a seal to seal the cup part, wherein the hole is formed in the inner area of the sealing part.

11 . The battery case of claim 1 , wherein the battery case includes multiple gas discharge parts.

12 . A method for manufacturing a pouch type secondary battery, the method comprising:
drawing a pouch film to form a cup part; punching a hole in at least one of the cup part or a sealing part of the pouch film, the sealing part extending away from the cup part; melting an electrolyte-resistant material and applying the electrolyte-resistant material to an inner circumferential surface of the hole; and attaching a gas discharge part to an exterior of the pouch film adjacent the hole, the gas discharge part configured to allow a gas to pass therethrough.

13 . The method of claim 12 , further comprising
a step of accommodating an electrode assembly in an accommodation space of the cup part, the electrode assembly including electrodes and separators, and a step of thermally pressing the sealing part.

14 . The method of claim 13 , wherein the step of attaching the gas discharge part is performed after the step of thermally pressing the sealing part.

15 . The method of claim 13 , wherein the step of attaching the gas discharge part is performed before the step of thermally pressing the sealing part.

16 . The method of claim 12 , wherein the electrolyte-resistant material comprises at least one of polypropylene (PP), polyethylene (PE), or epoxy.

17 . A pouch type secondary battery comprising:
an electrode assembly including electrodes and separators; and a battery case configured to accommodate the electrode assembly therein, wherein the battery case comprises:
a cup part having an accommodation space configured to accommodate the electrode assembly;
a sealing part extending to the outside of the cup part;
a gas discharge part attached to a hole, the hole formed through at least one of the cup part or the sealing part, the hole configured to allow a gas pass therethrough; and
a coating part applied to an inner circumferential surface of the hole and having electrolyte resistance,
wherein the gas discharge part comprises:
a gas discharge layer configured to allow the gas to pass therethrough; and

an outer functional layer formed on an outer surface of the gas discharge layer, the outer functional layer being hydrophobic.

Assignees

• Lg Energy Solution Ltd

Inventors

• Hwang Soo Ji
• Kim Sang Hun
• Choi Yong Su

Classifications

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title

• H01M50/55 Primary

  on the same side of the cell · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M50/121

  Organic material · CPC title

• H01M50/105

  Pouches or flexible bags · CPC title