Two copper-ion conducting solid-polymer electrolyte systems based on polyacrylonitrile (PAN) have been synthesized and characterized using DC polarization tests and impedance measurements. The system with 21 mol% PAN: 30 mol% EC: 45 mol% PC: 04 mol% CuCNS has a room temperature conductivity of 3.30 x 10(-5) S cm(-1) and an activation energy of 0.25 eV. The conductivity versus temperature plot obeys an Arrhenius type variation. It is predominantly an ionic conductor with negligible electronic conductivity. It has a high anionic transference number (t(-) = 0.80) due to CNS- ions and a low cationic transference number (t(+) = 0.20) due to Cu+ ions. The system with 20 mol% PAN: 41 mol% EC: 34 mol% PC: 5 mol% CuTf has a room temperature conductivity of 4.10 x 10(-3) S cm(-1) and an activation energy of 0.14 eV. It obeys the VTF equation. The system appears to be a mixed conductor with a cationic (Cu2+ /Cu+) transference number of t(+) = 0.50 and an electronic transference number of t(e) = 0.50 with negligible anionic conductivity. Both systems yielded free standing stable polymer electrolyte films. (C) 2000 Elsevier Science Ltd. All rights reserved.