Lithium Ion Battery Fabricated by Curable Copolyester/Al2O3 Composite-Coated Nonwoven Poly(ethylene terephthalate) Separator

The advantages of a curable copolyester (Ester)/Al2O3 composite and nonwoven poly(ethylene terephthalate) (NWPET) separator were combined in attempt to develop a separator system for lithium ion batteries that is predicted to be quite stable at high temperatures, up to 200 degrees C. Various properties of separators, including the battery performance of unit cells fabricated from them, were investigated. The curable copolyester/Al2O3 composite-coated nonwoven PET (Ester-NWPET) separator remained quite stable up to 200 degrees C when exposed in polycarbonate. In battery performance tests, the Ester-NWPET separator showed better cycle life than bare polyethylene (PE) separator because of enhanced wettability of the developed separator.