A copolymer P(MMA-AN-MALi) (PMAML) was synthesized by solution polymerization. It was then blended with PVDF for preparing porous membranes by solution casting

and the non-solvent or extration step was unnecessary in this process. A novel gelled polymer electrolyte based on the blend of PMAML and PVDF was obtained by soaking the polymer membrane in organic liquid electrolytes．The composition of the copolymer was determined from its 1H-NMR spectrum

and the result showed that the molar ratio of MMA:AN:MALi was about 68.6:21.5:9.9. The surface structure of the polymer film was characterized by SEM. The pores were well distributed in the surface of the membrane and the porous size was about 5 μm. The ionic conductivity of the polymer electrolyte was measured by the AC impedance method

and it was about 2.5×10-3 S·cm-1 at room temperature． The electrochemical stability window was carried out on the stainless steel electrode with lithium metal electrodes as the reference and counter electrodes by the linear sweep voltammetry method．The polymer electrolyte was electrochemically stable under 4.5 V．The diffusion coefficient of salt in the polymer electrolyte was measured using Li／GPE／Li non-blocking cell by the restricted diffusion experiment

and the value was about 8.12×10-7 cm2·s-1. The coulombic efficiency of the lithium ion battery with the polymer electrolyte in the initial charge-discharge cycle was calculated to be about 89％

and the discharge capacity of the first five cycles changed only in a small range．The test resuits display that the polymer electrolyte based on blends of PMAML and PVDF was electrochemical stable and can be used in lithium ion batteries.