Pouch type battery case, apparatus for molding the same, and pouch type secondary battery

Patent metadata

Field	Value
Publication number	US-11682808-B2
Application number	US-202117495386-A
Country	US
Kind code	B2
Filing date	Oct 6, 2021
Priority date	Oct 6, 2020
Publication date	Jun 20, 2023
Grant date	Jun 20, 2023

Abstract

Provided is a pouch type battery case. The pouch type battery case include a cup part configured to accommodate an electrode assembly, which is formed by stacking electrodes and separators, therein and a plurality of die edges configured to connect an outer wall of the cup part to a side extending from the outer wall. At least one die edge includes a first area formed to be rounded with a first curvature radius and a second area formed to be rounded with a second curvature radius less than the first curvature radius.

First claim

The invention claimed is:

1. A pouch type battery case, comprising:
a pouch film defining a first cup part including a bottom surface and a wall surrounding the bottom surface such that the first cup part is configured to accommodate an electrode assembly therein, the pouch film further including a side extending from the wall away from the first cup part and at least one die edge arranged at a junction of the side and the wall of the first cup part,
wherein the at least one die edge includes a first rounded area defining a first curvature radius configured to seat an electrode tab and a second rounded area defining a second curvature radius less than the first curvature radius.

2. The pouch type battery case of claim 1 , wherein the first curvature radius is between about 1.7 mm and about 2.7 mm.

3. The pouch type battery case of claim 1 , wherein the second curvature radius is approximately equal to or less than 1.2 mm.

4. The pouch type battery case of claim 3 , wherein the second curvature radius is approximately equal to or less than 0.7 mm.

5. The pouch type battery case of claim 4 , wherein the pouch film is molded and comprises:
a sealant layer made of a first polymer, the sealant layer formed at an innermost layer and with a thickness of between about 60 μm and about 100 μm;
a surface protection layer made of a second polymer, the surface protection layer formed at an outermost layer; and
a moisture barrier layer provided between the surface protection layer and the sealant layer,
wherein the moisture barrier layer comprises an aluminum alloy thin film having a thickness between about 50 μm and about 80 μm and a grain size between about 10 μm and about 13 μm.

6. The pouch type battery case of claim 1 , wherein a depth of the first cup part measured from the bottom of the first cup to the side is about 7 mm.

7. The pouch type battery case of claim 6 , further comprising a second cup part, wherein depths of the first and second cup parts are about 6.5 mm.

8. The pouch type battery case of claim 1 , wherein the at least one die edge includes two die edges formed on opposite sides of the first cup part.

9. The pouch type battery case of claim 8 , wherein each one of the two die edges comprises a single one of the first rounded areas.

10. The pouch type battery case of claim 9 , wherein each one of the two die edges comprises two of the second rounded areas.

11. The pouch type battery case of claim 10 , where the first rounded area is formed between the two second rounded areas on each respective die edge.

12. The pouch type battery case of claim 1 , wherein the at least one die edge includes one die edge formed on one side of the first cup part, and
the one die edge comprises a plurality of the first rounded areas and the second rounded area is formed between the plurality of the first rounded areas.

13. An apparatus for molding a battery case, comprising:
a die including a top surface on which a pouch film is configured to be seated, the top surface of the die defining at least one molding space recessed inwardly from the top surface, the die defining at least one pressing edge at a junction between the top surface and a wall of the at least one molding space; and
a punch disposed above the molding space, the punch arranged to descend into the molding space to mold the pouch film,
wherein the
at least one pressing edge comprises:
a first rounded pressing area formed with a first radius of curvature, the first rounded pressing area being configured to mold the pouch film in an area that seats an electrode tab; and
a second rounded pressing area formed with a second radius of curvature that is less than the first radius of curvature.

14. The apparatus of claim 13 , wherein the first radius of curvature is between about 1.5 mm and about 2.5 mm.

15. The apparatus of claim 14 , wherein the second radius of curvature is approximately equal to or less than 1 mm.

16. A pouch type secondary battery comprising:
an electrode assembly formed by stacking electrodes and separators; and
a battery case comprising a pouch film defining a first cup part including a bottom surface and a wall surrounding the bottom surface for accommodating the electrode assembly therein, a side extending away from the wall of the first cup part, and a plurality of die edges, each of the plurality of die edges being arranged at a junction of the side and the wall of the first cup part,
wherein at least one of the plurality of die edges comprises a first area defining a first inward concave recess upon which an electrode tab protruding from one side of the electrode assembly is seated, and a second area adjacent to the first area, the second area defining a second inward concave recess that is less concave than the first inward concave recess.

17. The pouch type secondary battery of claim 16 , wherein the first area is rounded and defines a first radius of curvature, and
the second area is rounded and defines a second radius of curvature that is less than the first radius of curvature.

18. The pouch type secondary battery of claim 16 , wherein the electrode assembly has a surface area of between about 15,000 mm 2 and about 100,000 mm 2 .

Assignees

• Lg Energy Solution Ltd

Inventors

• Oh Se Young
• Lee Chung Hee
• Ha Jeong Min
• Kim Geun Hee
• Kim Hyun Beom
• Kwon Hyung Ho

Classifications

• H01M50/136

  Flexibility or foldability · CPC title

• H01M50/107

  having curved cross-section, e.g. round or elliptic (H01M50/103, H01M50/109, H01M50/11 take precedence) · CPC title

• B29L2031/7146

  Battery-cases · CPC title

• B29C43/021

  characterised by the shape of the surface · CPC title

• H01M50/105 Primary

  Pouches or flexible bags · CPC title