Studies of proton conducting polymer electrolyte based on PVA, amino acid proline and NH4SCN

Proton conducting polymer electrolytes based on PVA, amino acid proline and NH4SCN were prepared by the solution casting technique. An increase in the amorphous nature of the polymer electrolytes was confirmed by X-ray diffraction analysis. DSC measurements showed a decrease in Tg with increasing salt concentration. The complex formation of the PVA/Proline/NH4SCN was investigated by FTIR analysis. The highest ionic conductivity of 1.17 × 10-3 S/cm for the 75 Mwt% PVA: 25 Mwt% Proline: 0.5 Mwt% of NH4SCN polymer electrolyte at ambient temperature was obtained by using AC impedance technique. Transference number measurements revealed the nature of the charge transport species in the polymer electrolyte. Electrochemical stability window of 3.61 V was measured by using the linear sweep voltammetry for the highest ionic conducting (75 Mwt% PVA: 25 Mwt% Proline: 0.5 Mwt% of NH4SCN) polymer membrane. A primary proton battery was constructed using the 75 Mwt% PVA: 25 Mwt% Proline: 0.5 Mwt% of NH4SCN polymer membrane and its performance was tested. Keywords: XRD, DSC, FTIR, AC impedance analyzer, LSV, Primary proton batter