Preparation and characterization of pva based solid polymer electrolytes for electrochemical cell applications

Solid polymer electrolyte films containing poly(vinyl alcohol) (PVA) and magnesium nitrate (Mg(NO₃)₂) were prepared by solution casting technique and characterized by using XRD, FTIR, DSC and AC impedance spectroscopic analysis. The amorphous nature of the polymer electrolyte films has been confirmed by XRD. The complex formation between PVA and Mg salt has been confirmed by FTIR. The glass transition temperature decreases with increasing the Mg salt concentration. The AC impedance studies are performed to evaluate the ionic conductivity of the polymer electrolyte films in the range of 303–383 K, and the temperature dependence seems to obey the Arrhenius behavior. Transport number measurements show that the charge transport is mainly due to ions. Electrochemical cell of configuration Mg/(PVA + M_g(NO₃)₂) (70:30)/(I₂ + C + electrolyte) has been fabricated. The discharge characteristics of the cell were studied for a constant load of 100 kΩ.