Abstract: A novel polymer material poly(methyl methacrylate-co-acrylonitrile-co-lithium methacrylate) (PMAML) was synthesized. The polymer electrolytes based on the blend of PMAML and PVDF-HFP (poly(vinylidene fluoride-co-hexafluoropropylene)) were prepared. The structure of PMAML was characterized by FTIR, and the surface morphology of PMAML/PVDF-HFP membrane was observed by SEM. Gelled polymer electrolytes were obtained by soaking PMAML/PVDF-HFP membrane in electrolyte solution. Ambient temperature conductivity of 2.6×10－3 S•cm－1 was obtained. The interfacial properties between the polymer electrolyte and lithium electrode were investigated by A.C. impedance. The effects of storage time, cyclic voltammetry and constant charge on interfacial impedance were studied. The interfacial resistance between polymer electrolyte and lithium electrode increased with the increasing of storage time. But the interfacial impedance decreased after the surface of lithium was refreshed by means of cyclic voltammetry or constant charge. The retention capability of electrolyte solution and the interfacial stability can be improved by introducing PMAML into PVDF-HFP.

Key words: Polymer electrolyte, Lithium ion battery, A.C. impedance, Interfacial property