A preferential polymer dissolution process was proposed for preparation of PVdF-co-HFP based membranes using PVA as the preferential polymer. The porosity and electrolyte uptake of membrane increases with removal of PVA content in the PVdF-co-HFP matrix. Scanning electron microscopy and gas adsorption/desorption method were used to reveal the porous structure of the polymer membranes. The ionic conductivity of porous polymer matrix was measured with increasing weight ratio of removal of PVA content and temperature when 1 M LiClO4 in EC and DEC (1: 1, v/v) are used as the liquid electrolyte counter part. Moreover, cycle test of lithium-ion polymer cell made by sandwiching the MPGPEM in between a carbon as anode and LiMg0.10Mn1.90O4 as cathode, showed great promise for the use of these porous separator in the lithium-ion batteries. (c) 2006 Elsevier B.V. All rights reserved.