A nonflammable polymeric gel electrolyte has been developed for rechargeable lithium battery systems. The gel film consists of poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP) swollen with lithium hexafluorophosphate (LiPF6) solution in ternary solvent containing trimethyl phosphate (TMP). High ionic conductivity of 6.2mScm−1 at 20°C was obtained for the gel electrolyte consisting of 0.8M LiPF6/EC+DEC+TMP (55:25:20) with PVdF-HFP, which is comparable to that of the liquid electrolyte containing the same electrolytic salt. Addition of a small amount of vinylene carbonate (VC) in the gel electrolyte improved the rechargeability of a graphite electrode. The rechargeable capacity of the graphite in the gel containing VC was ca. 300mAhg−1, which is almost the same as that in a conventional liquid electrolyte system.