A polymer gel electrolyte has been prepared based on polyvinyl alcohol, lithium salt and organic solvent N-methyl-2-pyrrolidone (NMP). This gel has the potential for use in secondary batteries and electrochemical capacitors. The conductivity of this gel electrolyte can be as high as 2 x 10(-3)-5.8 x 10(-4) S/cm at room temperature. Functioning as separator and electrolyte, this gel system was used to evaluate the specific capacitance of an electrochemical capacitor with carbon nanotube films as the active electrodes. Published by Elsevier B.V.