A polymer gel electrolyte supported with a microporous polyolefin membrane for lithium ion polymer batteries was prepared and characterized. The polymer gel electrolytes were based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), lithium salt and carbonate solvents. The gel electrolytes exhibited high ionic conductivity in the order of 10(-3) S cm(-1) at room temperature and were electrochemically stable up to + 5.0 V against Li+/Li. The membrane-supported gel electrolytes show excellent mechanical properties and good adhesion toward electrodes. Lithium-ion polymer cells, composed of a carbon anode and lithium manganese oxide cathode separated by the membrane-supported polymer electrolytes were assembled. The cells showed good electrochemical and rate performance during cycling.