Composite polymer electrolyte (PE) films comprising of thermoplastic polyurethane (TPU) and polyacrylonitrile (PAN) (denoted as TPU-PAN) have been prepared by two different processes. Scanning electron microscope (SEM) of the films reveal the differences in morphology between them. The electrochemical properties of composite electrolyte films incorporating LiClO4-propylene carbonate (PC) were studied. TPU-PAN based gel PE shows high ionic conductivity at room temperature. Thermogravimetric analysis informs that the composite electrolyte possesses good thermal stability with a decomposition temperature higher than 300 degreesC. Electrochemical stability in the working voltage range from 2.5 to 4.5 V was evident from cyclic voltammetry. Cycling performances of Li/PE/LiCoO2 cells were also performed to test the suitability of the composite electrolyte in batteries.