The electrochemical properties of gel electrolytes formed by the immobilization in a poly(acrylonitrile) matrix of solutions of common lithium salts (eg LiClO4, LiAsF6 and LiN(CF3SO2)2) in organic solvents (eg the propylene carbonate-ethylene carbonate mixture, gamma-butyrolactone or the gamma-butyrolactone-ethylene carbonate mixture) have been determined. The results indicate that in accordance with previous literature data, these electrolytes have a high ionic conductivity, a wide electrochemical stability window and a high lithium transference number. However, their application in long-life, rechargeable lithium polymer batteries may be hindered by the instability of the negative electrode interface.