Patent ID: 9385358
Filing Date: 2016-07-05
CPC Classification: B32B,H01M,Y02E

Claim Text:
1. A separator for a rechargeable lithium battery comprising: a porous substrate; and an adherence porous layer on at least one side of the porous substrate, the adherence porous layer comprising a first fluorovinylidene-hexafluoropropylene copolymer; a second fluorovinylidene-hexafluoropropylene copolymer different in structure from the first fluorovinylidene-hexafluoropropylene copolymer, and filler particles; wherein: the first fluorovinylidene-hexafluoropropylene copolymer has a weight average molecular weight of greater than or equal to about 1,000,000; the second fluorovinylidene-hexafluoropropylene copolymer includes a structural unit derived from fluorovinylidene and a structural unit derived from hexafluoropropylene, the hexafluoropropylene is included in an amount of greater than or equal to about 10 wt % based on a total amount of the hexafluoropropylene and the fluorovinylidene in the second fluorovinylidene-hexafluoropropylene copolymer, and the filler particles have a particle diameter (D50) of about 1.5 to about 3 μm and a particle diameter (D10) of greater than or equal to about 1 μm.