US 12,119,513 B2
Separator for lithium-ion secondary battery
Takahiko Kondo, Charlotte, NC (US); Kazunori Uchida, Tokyo (JP); and Shinya Hamasaki, Tokyo (JP)
Assigned to Asahi Kasei Kabushiki Kaisha, Tokyo (JP); and Celgard, LLC, Charlotte, NC (US)
Appl. No. 16/491,251
Filed by ASAHI KASEI KABUSHIKI KAISHA, Tokyo (JP); and CELGARD, LLC, Charlotte, NC (US)
PCT Filed Apr. 3, 2018, PCT No. PCT/US2018/025784
§ 371(c)(1), (2) Date Sep. 5, 2019,
PCT Pub. No. WO2018/187255, PCT Pub. Date Oct. 11, 2018.
Claims priority of provisional application 62/482,239, filed on Apr. 6, 2017.
Prior Publication US 2020/0035969 A1, Jan. 30, 2020
Int. Cl. H01M 50/44 (2021.01); B29C 55/00 (2006.01); B29C 55/04 (2006.01); B29C 55/12 (2006.01); B29K 23/00 (2006.01); B29K 105/04 (2006.01); B29L 31/34 (2006.01); H01M 10/0525 (2010.01); H01M 50/403 (2021.01); H01M 50/406 (2021.01); H01M 50/417 (2021.01); H01M 50/457 (2021.01); H01M 50/489 (2021.01); H01M 50/491 (2021.01)
CPC H01M 50/44 (2021.01) [B29C 55/005 (2013.01); B29C 55/04 (2013.01); B29C 55/12 (2013.01); H01M 10/0525 (2013.01); H01M 50/417 (2021.01); H01M 50/457 (2021.01); H01M 50/489 (2021.01); H01M 50/491 (2021.01); B29K 2023/12 (2013.01); B29K 2105/041 (2013.01); B29L 2031/3468 (2013.01); H01M 50/403 (2021.01); H01M 50/406 (2021.01)] 18 Claims
OG exemplary drawing
 
1. A separator for a lithium-ion secondary battery, comprising a microporous film, wherein the microporous film comprises:
a polyolefin resin (A) comprising polypropylene as a major component; and
interior surfaces of micropores in the microporous film are coated with a resin (B) different from the polyolefin resin (A), and a coated amount of the resin (B) is 5 to 70 weight % based on the total resin weight,
wherein the resin (B) is a C3 unit-containing polyolefin copolymer, or a polyolefin with an elastic modulus of 110 to 520 MPa at 25° C. and a melting point of no higher than 130° C.;
wherein the separator has a porosity of 41% to 58%, and an air permeability of 161 sec/100 cc to 244 sec/100 cc, and
wherein the separator is free of a fluorine-containing resin binder.