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

Patent metadata

Field	Value
Publication number	US-11626349-B2
Application number	US-202016823357-A
Country	US
Kind code	B2
Filing date	Mar 19, 2020
Priority date	Mar 15, 2013
Publication date	Apr 11, 2023
Grant date	Apr 11, 2023

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 TD/MD 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: a first microporous layer of a first polypropylene-based dry-processed resin layer with slit like pores bonded to a second layer of a wet-processed membrane with rounded pores, wherein the separator has a thickness of from about 18 to about 35 microns, and a ratio of MD/TD tensile strength from 1.5 to 3; and which exhibits an electrical resistance of 50,000 ohms-cm 2 at temperatures greater than about 135° C. to at least about 175° C.

2. The separator of claim 1 wherein said separator further has a puncture strength of greater than about 630 gf.

3. The separator of claim 2 wherein said separator has a dielectric breakdown of at least about 2000 V.

4. The separator of claim 1 wherein said second layer is made of a polyethylene-based resin.

5. The separator of claim 4 wherein said polyethylene-based resin is polyethylene or a blend containing polyethylene.

6. The separator of claim 1 has more than two layers.

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

8. The separator of claim 6 has a configuration of a dry processed membrane/a wet processed layer/a dry processed layer.

9. The separator of claim 1 has a ratio of TD/MD tensile strength in the range of about 1.5-3.0.

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

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

12. The separator of claim 1 has a thickness in the range of about 185.0-30.0 microns.

13. The separator of claim 1 has a thickness in the range of about 185.0-26.0 microns.

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

15. The separator of claim 1 has a dielectric breakdown of at least about 2000 V.

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

Assignees

• Celgard Llc

Inventors

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

Classifications

• H10W90/732

  between stacked chips · CPC title

• H10W90/22

  the stacked chips being on both top and bottom sides of a package substrate, interposer or RDL · CPC title

• H10W74/019

  using temporary auxiliary substrates (H10W74/017 takes precedence) · CPC title

• H10W72/9413

  on encapsulations · CPC title

• H10W72/874

  On different surfaces · CPC title