New polymer electrolytes based on ether sulfate anions for lithium polymer batteries

Multifunctional ionomers based on poly(oxyethylene)-co-poly(epichlorohydrin) random copolymers were blended with poly(oxyethylene) or cross-linked through urethane curing. Their conductivities, transference numbers and electrochemical stability were investigated. The cross-linked materials exhibited good mechanical properties. Gelled by liquid organic electrolytes they provided conductivities very close to that of the liquid electrolyte. A thorough comparative investigation of the cationic transference numbers of cross-linked and uncross-linked ionomers was performed. From these data it may be assumed that the cell electrical polarization is enough to induce chain disentanglements, which result in a significant anionic transference number