A novel microporous polymer electrolyte based on poly(vinylidene fluoride) and poly(ethylene oxide) (PVDF-PEO) blends was prepared by a simple phase inversion technique, in which the addition of PEO can obviously improve the pore configuration, such as pore size, porosity, and pore connectivity of PVDF-based microporous membranes, and hence, the room temperature ionic conductivity was greatly enhanced. The highest porosity of about 84% and ionic conductivity of about 2 mS cm(-1) can be obtained when the weight ratio of PEO to PVDF is 50%. This implies that PVDF-PEO blends based microporous polymer electrolyte can be used as candidate electrolyte and/or separator material for high-performance rechargeable lithium batteries. (c) 2005 Elsevier B.V. All rights reserved.