Poly(acrylonitrile)-Dimethylsulfoxide-ZnXn (X = CF3SO3, Cl, Br and SO4) Thin-Film Polymer Electrolytes

A new type of thin-film solid electrolytes based on poly(acrylonitrile)-dimethylsulfoxide (70÷80 wt. %)-ZnXn (X = CF3SO3, Cl, Br and SO4) system were prepared. The conductivity of the electrolytes, obtained by impedance spectroscopy, was in the range of ca. 10-4-7×10-3Ωcm-1 at room temperature. Conductivity dependence vs. temperature was of the Arrhenius type. Activation energy was of the order of 23 kJ mol-1 -26 kJ mol-1 for the PAN-DMSO-Zn(CF3SO3)2, PAN-DMSO-ZnCl2 and PAN-DMSO-ZnBnelectrolytes. The activation energy for the corresponding solid electrolytes containing zinc sulphate, PAN-DMSO-ZnSO4, was considerably lower (ca. 15 kJ mol-1 - 19 kJ mol-1). A passivation phenomenon at the Ztuelectrolyte interface was observed in long-tenn impedance spectra of the Zn|etectrolyte|Zn system. The decomposition voltage as well as redox properties of the electrolytes were determined by cyclic voltammetry. The exchange current densities at the Zn|electrolyte interface, determined for the PAN-DMSO-ZnSO4 and PAN-DMSO-Zn(CF3SO3)2 electrolytes, were considerably higher than those for the PAN-DMSO-ZnCl2 and PAN-DMSO-ZnBr2 systems.