A hybrid composite membrane is prepared by electrospinning poly(vinylidene fluoride-co-chlorotrifluoroethylene) copolymer and Al2O3 powder with a microfibrous form on both sides of a polyethylene membrane. The composite membrane shows better thermal stability and wettability for liquid electrolyte solution than polyethylene membrane. The lithium-ion cell assembled with the composite membrane exhibits good capacity retention and high rate performance due to the effective encapsulation of the electrolyte solution in the cell and the adhesive properties of the swollen polymer towards electrodes. The hybrid composite membrane prepared by the electrospinning method is expected to be a separator with enhanced thermal stability and good cycling performance for application in lithium-ion batteries.