US 12,272,838 B2
Separator, process for preparing the same, lithium ion secondary battery, battery module, battery pack and apparatus
Wei Li, Ningde (CN); Chao Jin, Ningde (CN); Haihao Shi, Ningde (CN); and Qian Li, Ningde (CN)
Assigned to Contemporary Amperex Technology (Hong Kong) Limited, Hong Kong (CN)
Filed by CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED, Hong Kong (CN)
Filed on Dec. 30, 2021, as Appl. No. 17/565,499.
Application 17/565,499 is a continuation of application No. PCT/CN2020/113801, filed on Sep. 7, 2020.
Claims priority of application No. 201910874822.5 (CN), filed on Sep. 17, 2019.
Prior Publication US 2022/0123436 A1, Apr. 21, 2022
Int. Cl. H01M 50/449 (2021.01); H01M 10/0525 (2010.01); H01M 50/403 (2021.01); H01M 50/417 (2021.01); H01M 50/454 (2021.01)
CPC H01M 50/454 (2021.01) [H01M 10/0525 (2013.01); H01M 50/403 (2021.01); H01M 50/417 (2021.01); H01M 2220/20 (2013.01)] 12 Claims
 
1. A separator, comprising a porous base film and a functional coating disposed on at least one surface of the porous base film, wherein,
the functional coating comprises polyimide nanosheets, and the polyimide nanosheets are stacked irregularly to form a lamellar loose structure; and a thickness ratio of the functional coating to the porous base film is from 0.1 to 1.0,
the functional coating further comprises a binder; and the binder comprises one or more of polyfluoroolefin binders, polyacrylate binders, polyacrylic acid binders, polyurethane binders, silicone binders, epoxy binders and cellulose-derived binders, and
a mass percentage of the binder in the functional coating is from 5% to 40%; and a mass percentage of the polyimide nanosheets in the functional coating is from 60% to 95%.