Poly(vinylidenefluoride-hexafluoropropylene)[P(VDF-HFP)] membrane with porous structure was prepared by a simple phase separation process. The gel polymer electrolyte (GPE) prepared by combining the porous membrane with N-methyl-N-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquid shows good thermal stability, high anodic oxidation potential (>5.0 V vs. Li/Li+) and good interfacial stability with lithium electrode. The lithium sulfur battery with the GPE delivers an initial discharge capacity 1217.7 mAh g(-1) and maintains a reversible capacity of 818 mAh g(-1) after 20 cycles at a current density of 50 mA g(-1). (c) 2012 Elsevier B.V. All rights reserved.