Poly(methyl methacrylate) (PMMA) was anchored to multiporous poly(vinylidine fluoride) (PVDF) surface via electron beam preirradiation grafting technique to prepare PVDF/PMMA brushes. The conformation of the PVDF/PMMA brushes was verified through Attenuated total reflection-Fourier transform infra red spectroscopy (ATR-FTIR), energy dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). Thermal stability of PVDF/PMMA brushes was characterized by thermo gravimetric analysis (TGA). The degradation of PVDF/PMMA brushes showed a two-step pattern. PVDF/PMMA brushes membrane could be used as polymer electrolyte in lithium-ion rechargeable batteries after it was activated by uptaking 1 M LiPF6/EC-DMC (ethylene carbonate/dimethyl carbonate; EC:DMC = 1:1 by volume) electrolyte solution. The activated membrane showed high ionic conductivity, 6.1 X 10(-3) S cm(-1) at room temperature, and a good electrochemical stability up to 5.0 V The excellent performances of multi porous PVDF-g-PMMA membranes suggest that they are suitable for application in high-performance lithium-ion batteries.(C) 2008 Wiley Periodicals, Inc.