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Abstract. Copper-ion conducting solid-polymer electrolyte systems based on Polyvinyl alcohol (PVA) has been prepared by solution cast technique. UV-VIS data show a broad peak in the wavelength region 600-800 nm due to complex formation. The 30 wt.% Cu(NO3) 2 doped system has a maximum conductivity of 1.6 x 10 5 Scm 1 at room temperature. The conductance spectrum shows two distinct regions: a dc plateau and a dispersive region. The dielectric spectra show an increase in the dielectric constant with decreasing frequency. The transference number measurements reveal that the transport in these electrolytes is mainly due to ions.

The proton-conducting polymer electrolytes based on poly (N-vinylpyrrolidone) (PVP), doped with ammonium chloride (NH 4 Cl) in different molar ratios, have been prepared by solution-casting technique using distilled water as solvent. The increase in amorphous nature of the polymer electrolytes has been confirmed by XRD analysis. The FTIR analysis confirms the complex formation of the polymer with the salt. A shift in glass transition temperature (T g ) of the PVP/NH 4 Cl electrolytes has been observed from the DSC thermograms which indicates the interaction between the polymer and the salt. From the AC impedance spectroscopic analysis, the ionic conductivity of 15 mol% NH 4 Cl-doped PVP polymer complex has been found to be maximum of the order of 2.51×10 −5 Scm −1 at room temperature. The dependence of T g and conductivity upon salt concentration has been discussed. The linear variation of the proton conductivity of the polymer electrolytes with increasing temperature suggests the Arrhenius type thermally activated process. The activation energy calculated from the Arrhenius plot for all compositions of PVP doped with NH 4 Cl has been found to vary from 0.49 to 0.92 eV. The dielectric loss curves for the sample 85 mol% PVP:15 mol% NH 4 Cl reveal the lowfrequency β relaxation peak pronounced at high temperature, and it may be caused by side group dipoles. The relaxation parameters of the electrolytes have been obtained by the study of Tanδ as a function of frequency.