PREPARASI FILM ELEKTROLIT GEL POLIMER KITOSAN-KI/Iz SEBAGAI ELEKTROLIT REDOKS PADA DYE-SENSITIZED SOLAR CELL (DSSC)

Preparation of electrolyte films of chitosan-KI/I2 polymer gel by solvent casting technique as the redox electrolyte for DSSC have been done. The aims of this research are to study the redox properties and ionic conductivity of the chitosan-KI/I2 polymer gel electrolyte and analyze ionic conductivity, crystallinity and thermal properties of the corresponding polymer gel electrolyte films. The optimum gel formation time was firstly determined by varying gel formation time (0, 1, 2, 3, 4, 5, 6 and 7 hours). Then, the influence of the amount of KI (10, 20, 30, 40, 50% (w/w)) on the gel system made at optimum gel formation time was studied. The redox properties of chitosan gel electrolytes were studied by cyclic voltammetry. While, the ionic conductivity of the corresponding electrolyte films of chitosan polymer gel were analyzed by Electrochemical Impedance Spectroscopy (EIS). The film crystallinity was analyzed by X-ray diffraction methods. TG/DTA was used to evaluate the thermal properties of the films. Ethylene glycol and glycerol were added to make plasticized-chitosan polymer gel electrolyte films. The conductivity of the films were studied by EIS. The results showed that the optimum gel formation time was 6 hours with conductivity of 1.73 x 10-4 S. Ionic conductivity and the peak current of oxidation/reduction of the gel electrolyte increases with increasing the amount of KI. Chitosan-50% KI/I2 electrolyte film resulted in the highest ionic conductivity (1.52 x 10-7 S cm-1). Crystallinity of the electrolyte films decreases with increasing amount of KI.. The addition of glycerol and ethylene glycol increased the ionic conductivity of the electrolyte films as of 1.07 x 10-6 and 1.84 x 10-6 S cm-1 for kitosan/EG-KI/I2 kitosan/gliserol-KI/I2, respectively. Chitosan electrolyte films have good thermal properties with relatively high decomposition temperature (270-320 °C