Composite film and manufacturing method for the same and battery comprising composite film

Patent metadata

Field	Value
Publication number	US-10601013-B2
Application number	US-201715853245-A
Country	US
Kind code	B2
Filing date	Dec 22, 2017
Priority date	Aug 31, 2017
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

A composite film, a manufacturing method for the same, and a battery comprising the composite film are provided. The composite film includes a first layer and a second layer on a side of the first layer. The first layer includes a first polyolefin. The first polyolefin has an orientation function of at least 0.6. The first polyolefin has a repeating unit of

wherein R is an alkyl group having 2, 3, 4, or 5 carbon atoms. The second layer includes a second polyolefin. The second polyolefin has an orientation function of at least 0.5. The second polyolefin has a repeating unit of

wherein A is a hydrogen or a methyl group.

First claim

What is claimed is:

1. A composite film, comprising:
a first layer comprising a first polyolefin having an orientation function of at least 0.6 and a repeating unit of

wherein R is an alkyl group having 2, 3, 4, or 5 carbon atoms; and
a second layer on a side of the first layer and comprising a second polyolefin having an orientation function of at least 0.5 and a repeating unit of

wherein A is a hydrogen or a methyl group.

2. The composite film according to claim 1 , wherein a melting temperature (Tm) of the first polyolefin differs with a melting temperature of the second polyolefin by at least 55° C.

3. The composite film according to claim 1 , wherein the first polyolefin has a melting temperature within a range of 220 to 240° C., and the second polyolefin has a melting temperature within a range of 130 to 165° C.

4. The composite film according to claim 1 , wherein the first polyolefin has a melting flow index of 4 g/10 min to 30 g/10 min, the second polyolefin has a melting flow index of 0.2 g/10 min to 6 g/10 min.

5. The composite film according to claim 1 , wherein the orientation function of the first polyolefin is 0.6 to 0.95.

6. The composite film according to claim 5 , wherein a melting temperature of the first polyolefin differs with a melting temperature of the second polyolefin by at least 55° C.

7. The composite film according to claim 5 , wherein the first polyolefin has a melting temperature within a range of 220 to 240° C., and the second polyolefin has a melting temperature within a range of 130 to 165° C.

8. The composite film according to claim 5 , wherein the first polyolefin has a melting flow index of 4 g/10 min to 30 g/10 min, and the second polyolefin has a melting flow index of 0.2 g/10 min to 6 g/10 min.

9. The composite film according to claim 1 , wherein the first layer is formed of a material selected from polymethylpentene, polybutene, and a combination thereof, and the second layer is formed of a material selected from polyethylene, polypropylene, and a combination thereof.

10. The composite film according to claim 1 , further comprising a third layer on a side of the first layer opposite to the second layer and comprising a third polyolefin having an orientation function of at least 0.5 and a repeating unit of

wherein A is a hydrogen or a methyl group.

11. A manufacturing method for composite film, comprising:
performing a co-extrusion process to a first polyolefin and a second polyolefin to form a composite film comprising a first layer and a second layer, wherein the first layer comprises the first polyolefin having an orientation function of at least 0.6 and a repeating unit of

with R being an alkyl group having 2, 3, 4, or 5 carbon atoms, and the second layer is on a side of the first layer and comprises the second polyolefin having an orientation function of at least 0.5 and a repeating unit of

with A being a hydrogen or a methyl group.

12. The manufacturing method for composite film according to claim 11 , further comprising performing a pore forming-extending process to the composite film.

13. The manufacturing method for composite film according to claim 11 , wherein the co-extrusion process has a cooling wheel temperature within a range of 15 to 40° C. and a cooling wheel speed of 8 m/min to 20 m/min.

14. A battery, comprising the composite film according to claim 1 or is manufactured by the manufacturing method for composite film, comprising:
performing a co-extrusion process to a first polyolefin and a second polyolefin to form a composite film comprising a first layer and a second layer, wherein the first layer comprises the first polyolefin having an orientation function of at least 0.6 and a repeating unit of

with R being an alkyl group having 2, 3, 4, or 5 carbon atoms, and the second layer is on a side of the first layer and comprises the second polyolefin having an orientation function of at least 0.5 and a repeating unit of

with A being a hydrogen or a methyl group.

Assignees

• Ind Tech Res Inst

Inventors

• Lee Chih-Hung
• TSAI Ang-Ta
• Li Yen-Cheng

Classifications

• B29L2031/3468

  Batteries, accumulators or fuel cells (battery cases B29L2031/7146) · CPC title

• B29C2071/022

  Annealing · CPC title

• B29K2023/12

  PP, i.e. polypropylene · CPC title

• H01M10/052

  Li-accumulators · CPC title

• B29L2007/00

  Flat articles, e.g. films or sheets (B29L2024/00 takes precedence) · CPC title