Multilayer hybrid battery separators for lithium ion secondary batteries and methods of making same

Patent metadata

Field	Value
Publication number	US-9455432-B2
Application number	US-201414210507-A
Country	US
Kind code	B2
Filing date	Mar 14, 2014
Priority date	Mar 15, 2013
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

A multi-layered battery separator for a lithium secondary battery includes a first layer of a dry processed membrane bonded to a second layer of a wet processed membrane. The first layer may be made of a polypropylene based resin. The second layer may be made of a polyethylene based resin. The separator may have more than two layers. The separator may have a ratio of MD/TD tensile strength in the range of about 1.5-3.0. The separator may have a thickness of about 35.0 microns or less. The separator may have a puncture strength of greater than about 630 gf. The separator may have a dielectric breakdown of at least about 2000V.

First claim

We claim:

1. A multi-layered battery separator for a lithium secondary battery comprises at least a first polypropylene based resin layer of a dry processed microporous membrane with slit-like pores bonded to a second polyethylene based resin layer of a wet processed microporous membrane with rounded pores, the separator having a ratio of MD/TD tensile strength in the range of about 1.5-3.0, a thickness of about 35.0 microns or less, a puncture strength of greater than about 630 gf, and a dielectric breakdown of at least about 2000V.

2. The separator of claim 1 has at least three layers.

3. The separator of claim 1 has only two layers.

4. The separator of claim 1 wherein said polypropylene based resin is polypropylene or a blend containing polypropylene.

5. The separator of claim 1 wherein said polyethylene based resin is polyethylene or a blend containing polyethylene.

6. The separator of claim 2 has a configuration of a polypropylene layer/a polyethylene layer/a polypropylene layer.

7. The separator of claim 2 has a configuration of a dry processed membrane/a wet processed membrane/a dry processed membrane.

8. The separator of claim 1 has a ratio of MD/TD tensile strength in the range of about 1.6-2.5.

9. The separator of claim 1 has a ratio of MD/TD tensile strength in the range of about 1.8-2.2.

10. The separator of claim 1 has a thickness in the range of about 5.0-30.0 microns.

11. The separator of claim 1 has a thickness in the range of about 5.0-26.0 microns.

12. The separator of claim 1 has a puncture strength in the range of about 630-1500 gf.

13. The separator of claim 1 has a dielectric breakdown in the range of about 2000-5000V.

14. A battery comprising the separator of claim 1 .

15. A battery comprising the separator of claim 2 .

16. A battery comprising the separator of claim 3 .

17. A battery comprising the separator of claim 7 .

Assignees

• Celgard Llc

Inventors

• Shi Lie
• Watson Jill V
• Call Ronald W
• Smith Ronnie E

Classifications

• B32B2266/025

  Polyolefin · CPC title

• B32B37/12

  characterised by using adhesives · CPC title

• B32B2307/204

  Di-electric · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• B32B2457/10

  Batteries · CPC title