A novel macroporous polymer electrolyte based on poly(vinylidene fluoride) (PVDF) and poly(ethylene oxide)-block-poly(methyl methacrylate) (PEO-b-PMMA) block copolymers blends was prepared by a phase inversion technique. The crystallinity of the polymer matrix was found to decrease with increase of PEO-b-PMMA content, which was confirmed by DSC thermal analyses. The pore structure and connectivity could be improved with addition of PEO-b-PMMA in the polymer matrix. The resulting macroporous polymer electrolyte exhibited high ionic conductivity, 2.79 x 10(-3) S cm(-1) at room temperature, and a good electrochemical stability up to 5.0V (vs. Li/Li+). These results showed that it is of great potential application in polymer lithium ion batteries. (C) 2009 Elsevier B.V. All rights reserved.