Effect of High Ammonium Salt Concentration and Temperature on the Structure, Morphology, and Ionic Conductivity of Proton-Conductor Solid Polymer Electrolytes Based PVA

Membranes (Basel). 2020 Sep 28;10(10):262. doi: 10.3390/membranes10100262.

Abstract

Polyvinyl alcohol (PVA) based proton-conducting solid polymer electrolyte was prepared with a high salt concentration of ammonium nitrate (NH4NO3) by the technique of solvent casting. From the X-ray diffraction studies, the semicrystalline nature of PVA with the inclusion of NH4NO3 was studied. XRD analysis indicates that the highest ion conductive sample exhibits the minimum crystalline nature. The decreasing trend of Jonscher-exponent with temperature rise reveals that the present system is insured by the correlated barrier hopping (CBH) model. The maximum room temperature conductivity was found to be 5.17 × 10-5 S/cm for PVA loaded 30 wt.% of NH4NO3. The ionic transport of the proton-conducting solid polymer electrolyte was studied at the temperature range of 303-353 K. The conductivity-temperature relationship of the systems was analyzed using both the Arrhenius and Vogel-Tammann-Fulcher (VTF) models to explain the ionic hopping mechanism for the system.

Keywords: CBH; VTF; arrhenius; ionic conductivity; polymer electrolyte; proton conductor.