Ion transport in proton conducting solid polymer electrolytes

Abstract

In this communication the ion transport properties of polyvinyl alcohol complexed with orthophosphoric acid (H3PO4) have been investigated. The proton conduction is confirmed by hydrogen gas evolved at the cathode of the coulometer and the transference number of H+ ion has been determined. The transient ionic current (TIC) technique has been used to detect the mobile ionic species and their mobilities are evaluated. The ionic mobility was found to be of the order of 10-4 cm2.V -1.s-1 for H+ ions. It is observed that the bulk electrical conductivity increases with the temperature following the Arrhenius type behaviour. Variation of charge carrier concentration with the molar ratio of H3PO4 in the sample reveals that the carrier concentration is largely affected by the amount of dopant in the complexes.