Composite polymer electrolyte films consisting of poly(ethylene glycol)-based thermoplastic polyurethane (TPU-PEG2000 and TPU-PEG400) blended with linear poly(ethylene oxide) incorporating 100wt.% LiClO4-PC and LiClO4-PC/EC have been prepared for investigating their ionic conductivities and electrochemical stability with lithium metal. Alternating current (AC) impedance experiments were performed to determine the ionic conductivities of gel-type electrolytes. One of the composite polymer electrolytes exhibits an:ionic conductivity of 1.6 x 10(-3) S cm(-1) at room temperature. AC impedance was also used to study the stability of bulk resistance and interfacial resistance between Li metal and electrolytes; Results of Linear sweep voltammetry (LSV) and cyclic voltammetry, (CV) show that the composite electrolytes have good electrochemical stability up to the working voltage 5.5 V and good reversibility for lithium kinetics.