Polymer electrolytes based on the interpenetrating network approach (PE-IPN), were obtained starting from functionalized poly-ether network precursors, in the presence of lithium salts and plasticizers. PC (propylencarbonate), TGME (tetraethylenglycol dimethylether) and mixtures of PC-TGME, PC-EC (ethylencarbonate), EC-TGME, EC-DEC (diethylcarbonate) were employed as plasticizers; LiBF4, LiCF3SO3, LiClO4 and LiPF6 were the preferred lithium salts. Self-consistent membranes were obtained as thin film by a dry procedure employing LiBF4 as the catalyst for polymerization. Ionic conductivities (sigma) were measured at various plasticizer and salt contents as a function of T (60 to -20 degrees C); at room temperature conductivities in the range of 10(-3) S cm(-1) and 10(-4) S cm(-1) at -20 degrees C were achieved. Practical cells of 1 cm(2), based on Li/V6O13 couple, were assembled and their cyclability at various discharge currents was evaluated; up to 1000 cycles were obtained at high discharge current (0.5 mA/cm(2)).