A novel silsesquioxanes modified electrospun composite fibrous separator by in-situ crosslinking method for lithium-ion batteries

Abstract

Microporous electrospun PVDF-HFP nonwoven separators have advantages of higher porosities and better wettabilities compared with conventional polyolefin, but suffer from low mechanical strength and excessive swelling in electrolyte. To enhance the mechanical properties, thermal and dimensional stabilities as well as electrochemical performance of electrospun separators, cross-linked membranes covalently integrated with hybrid silsesquioxane components were fabricated by in-situ crosslinking method, obtaining armor-like shell structure coated on PVDF-HFP fibers. The silsesquioxanes crosslinked PVDF-HFP fibers separator (SQ-PFF) exhibits excellent tensile and puncture strength, superior thermal and dimensional stabilities. Besides, the SQ-PFF prepared cells revealed remarkable discharge capacity and excellent cycling performance ascribing to the high lithium-ion conductivity and the enhanced cross-linked structure.