AC and DC electrical transport properties of potassium permanganate doped PVA-PVP solid polymer electrolyte

PVA-PVP based polymer electrolyte doped with potassium permanganate (KMnO₄) from 0.0 wt% up to 4.7 wt% were prepared by solution casting technique. Electrical transport properties of the prepared films were studied by DC electrical measurements, DC polarization technique, frequency and temperature dependent AC measurements. From DC electrical measurements, the activation energy was determined using Arrhenius equation. The data was found to obey three dimensional VRH model. DC polarization technique revealed that the majority of charge carriers are ions. AC impedance study was carried out in the frequency range starting from 12 Hz up to 200 kHz, at various set temperatures, from 303 K up to 363 K. Pure PVA-PVP blend (0.0 wt%/DL), 0.07 wt% and 4.7 wt% (DL) KMnO₄ doped samples were considered for detailed electrical study. The bulk conductivity was found to increase with temperature, implying the process to be a thermally activated one, a result of thermally induced increase in mobility of polymer chains. An equivalent circuit was formulated for the samples under study. The study of dielectric parameters such as ε′ and ε″ revealed the orientation of dipoles on application of the AC field. Temperature dependent study at various fixed frequencies was carried out in order to determine the activation energy for mobility of charge carriers. The study revealed an enhancement in ionic conductivity, due to the contribution of dopant ions. An increase in bulk conductivity was observed with increase in DL. (paper)