Hybrid solid polymer electrolytes (HSPE) of high ionic conductivity were prepared using polyethylene oxide (PEG), polyacrylonitrile (PAN), propylene carbonate (PrC), ethylene carbonate (EC), and LiClO4. These electrolyte films were dry, free standing, and dimensionally stable. The HSPE films were characterized by constructing symmetrical cells containing nonblocking lithium electrodes as well as blocking stainless steel electrodes. Studies were made on ionic conductivity, electrochemical reaction, interfacial stability, and morphology of the films using alternating current impedance spectroscopy, infrared spectroscopy, and scanning electron microscopy. The properties of HSPE were compared with the films prepared using (i) PEO, PrC, and LiClO4; and (ii) PAN, PrC, EC, and LiClO4. The specific conductivity of the HSPE films was marginally less. Nevertheless, the dimensional stability was much superior. The interfacial stability of lithium was similar in the three electrolyte films.