The usefulness of poly(dimethyl siloxane-co-ethylene oxide) (P(DMS-co-EO)) copolymer as an ion conducting matrix was investigated. The electrochemical properties were studied by electrochemical impedance spectroscopy and cyclic voltammetry. The glass transition temperature (T g) and degree of crystallization as a function of salt concentration were examined by differential scanning calorimetry. Ionic conductivities as high as 2.6×10−4 Scm−1 were determined at 25°C for copolymers films with 5wt.% LiClO4. These same films had an electrochemical stability window of 5V. The pseudo-activation energy as a function of salt concentration was obtained using the Vogel–Tamman–Fulcher (VTF) equation.