Poly(vinyl alcohol) Based Polymer Gel Electrolytes: Investigation on Their Conductivity and Characterization

Abstract

Polymer gel electrolytes were prepared using poly(vinyl alcohol) (PVA) as polymer matrix. 1-methyl-2-pyrrolidone (NMP) and gamma-butyrolactone (GBL) were preferred as the organic solvents. The alkali metal iodide salt (KI) and iodine (I-2) were used as the redox couple. Liquid electrolytes with different concentrations of KI were prepared by dissolving iodide salt/iodine in the binary NMP: GBL (volume ratio 7: 3) solvent mixture. PVA was added into the liquid electrolytes and then the resulting mixture was stirred at 110 degrees C for 1 h. Gel form was obtained at room temperature. The highest ionic conductivity at room temperature is 8.41 mS/cm. The temperature dependence of ionic conductivity with respect to the all concentration of KI shows the Arrhenius behaviour. Characterizations of polymer gel electrolytes were performed using the Fourier transform infrared, thermal gravimetric analysis, and differential scanning calorimetry techniques.