Polyvinyl pyrrolidone/Mg(ClO4)2 solid polymer electrolyte: structural and electrical studies

Polymer electrolytes comprising polyvinyl pyrrolidone (PVP) as host polymer and Mg(ClO₄)₂ as dopant salt have been prepared by solution casting technique using double-distilled water as solvent. The changes in the structural properties on the incorporation of dopant were investigated by XRD and FTIR analysis. The ionic conductivity and dielectric behavior were explored using AC impedance spectroscopy. The ionic conductivity increases with increasing dopant concentration. The conductivity enhancement with the increasing salt concentration is correlated with the increase in amorphous nature of the electrolytes. The frequency dependence of electrical conductivity obeys the universal Jonscher power law. The electrical modulus representation shows a loss feature in the imaginary component. The distribution of relaxation times was indicated by a deformed arc form of the Argand plot. The relative dielectric constant (ε _r ) decreases with increase in frequency in the low frequency region whereas a frequency-independent behavior is observed in the high frequency region. The total ionic transference number studies have confirmed that the mobile charge carriers are ions. Results obtained by cyclic voltammetry on SS/60 mol% PVP/40 mol% Mg(ClO₄)₂ SPE/SS symmetrical cell show evidence for reversibility.