US 11,929,458 B2
Separator having inorganic coating layer including small weight average molecular weight and low melting point PVDF, and method for manufacturing the same
Joo-Sung Lee, Daejeon (KR); and A-Young Lee, Daejeon (KR)
Assigned to LG Chem, Ltd., (KR)
Appl. No. 16/982,838
Filed by LG Chem, Ltd., Seoul (KR)
PCT Filed Jul. 15, 2019, PCT No. PCT/KR2019/008720
§ 371(c)(1), (2) Date Sep. 21, 2020,
PCT Pub. No. WO2020/013675, PCT Pub. Date Jan. 16, 2020.
Claims priority of application No. 10-2018-0081891 (KR), filed on Jul. 13, 2018; and application No. 10-2018-0132497 (KR), filed on Oct. 31, 2018.
Prior Publication US 2021/0057705 A1, Feb. 25, 2021
Int. Cl. H01M 10/0525 (2010.01); H01M 50/403 (2021.01); H01M 50/443 (2021.01); H01M 50/446 (2021.01); H01M 50/451 (2021.01); H01M 50/457 (2021.01); H01M 50/489 (2021.01); H01M 50/491 (2021.01)
CPC H01M 10/0525 (2013.01) [H01M 50/403 (2021.01); H01M 50/443 (2021.01); H01M 50/446 (2021.01); H01M 50/451 (2021.01); H01M 50/457 (2021.01); H01M 50/489 (2021.01); H01M 50/491 (2021.01)] 14 Claims
OG exemplary drawing
 
1. A method for manufacturing a separator for an electrochemical device, which comprises:
(S1) preparing a slurry for forming an inorganic coating layer, the slurry comprising a solvent, inorganic particles and a binder resin;
(S2) applying the slurry for forming the inorganic coating layer to at least one surface of a porous substrate; and
(S3) dipping the porous substrate coated with the inorganic coating layer in a solidifying solution containing a non-solvent,
wherein the binder resin in the slurry comprises a vinylidene fluoride homopolymer or a copolymer of vinylidene fluoride with another copolymerizable monomer in an amount of 90 wt % or more based on 100 wt % of the binder resin, the vinylidene fluoride homopolymer or the copolymer of vinylidene fluoride with another copolymerizable monomer has a weight average molecular weight of 400,000 or less and a melting point of 140° C. or less,
wherein a weight ratio of the binder resin to the inorganic particles in the slurry is at 30:70 to 60:40,
wherein the dipping is carried out once, or twice or more, and an initial solidifying solution temperature is controlled to a temperature equal to or higher than 5° C. and less than 20° C.