A novel microporous polymer electrolyte (MPE) based on poly (vinylidene fluoride) (PVDF)/poly (ethylene oxide) (PEO) star polymer was prepared by a phase inversion technique. The effects of PEO chain length of star polymer and temperature on ionic conductivity of MPE were investigated. The results showed that the ionic conductivity increased generally with the chain length of star polymer arms without any abrupt change. Effects of star polymer mass fraction on electrolyte uptake and leakage were also discussed. The distribution of holes and connectivity was improved with star polymer mass fraction increased, thus resulted in a high ionic conductivity (3.03 x 10(-3) S cm(-1)) exhibited at room temperature. Moreover, the electrochemical stability window was observed above 5.0 V (vs. Li/Li+). All these results showed that this MPE could be served as a good candidate for lithium ion batteries. (C) 2015 Elsevier B.V. All rights reserved.