Lithium ion battery

A microporous polymer separator for use in a lithium ion battery, comprising:

• a discrete layer of a polyolefin;
• an other discrete layer of a polymer, the polymer being 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;
• and
• one or more chelating agents grafted, as a substitute pendant group, onto at least one of the polyolefin or the polymer, the one or more chelating agents 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.

A lithium ion battery, comprising:

• a negative electrode comprising a lithium host material and a polymer binder material;
• a positive electrode comprising a lithium-based active material and a polymer binder material;
• and
• a microporous polymer separator situated between the negative electrode and the positive electrode, the microporous polymer separator 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 and
• one or more chelating agents grafted onto the polymer of the microporous polymer separator as a substitute pendant group, and wherein the one or more chelating agents 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.