Patent ID: 8568930

Claim:
A microporous polymer separator for use in a lithium ion battery, comprising: a polymer chosen from polyethylene terephthalates, polyvinylidene fluorides, polyamides, polyurethanes, polycarbonates, polyesters, polyetheretherketones, polyethersulfones, polyimides, polyamide-imides, polyethers, polyoxymethylenes, polybutylene terephthalates, polyethylenenaphthenates, polybutenes, polyolefins, polyolefin copolymers, acrylonitrile-butadiene styrene copolymers, polystyrene copolymers, polymethylmethacrylates, polyvinyl chlorides, polysiloxane polymers, polybenzimidazoles, polybenzoxazoles, polyphenylenes, polyarylene ether ketones, polyperfluorocyclobutanes, polytetrafluoroethylenes, polyvinylidene fluoride copolymers, polyvinylidene fluoride terpolymers, polyvinylidene chlorides, polyvinylfluorides, liquid crystalline polymers, polyaramides, polyphenylene oxides, or combinations thereof; one or more chelating agents grafted onto the polymer as a substitute pendant group, the one or more chelating agents configured to complex with metal cations in a manner sufficient to not affect movement of lithium ions across the microporous polymer separator during operation of the lithium ion battery.