Effect of Laponite® nanoclay dispersion on electrical, structural, and photovoltaic properties of dispersed [Poly(Ethylene oxide)-succinonitrile]-LiI-I2 solid polymer electrolyte

Abstract The effect of laponite® clay dispersion on the electrical, structural, optical, thermal, and photovoltaic properties of [poly (ethylene oxide)-succinonitrile]-LiI-I2 solid polymer electrolytes is reported for the first time. The nanoclay belongs to the family of smectite clay minerals and offers a high surface-to-volume ratio, charged surface, galleries, and ionic species. The dispersion has increased the room-temperature electrical conductivity to ~0.5 mS cm−1 for the optimum conducting electrolyte (OCE; x = 2.5%) without altering the pseudo-activation energy. The change is explained using the percolation model utilizing the formation of a space-charge region by the clay. Fourier-transform infrared spectroscopy reveals the greater interaction between clay and succinonitrile than clay and poly (ethylene oxide) and the formation of amorphous domains for the OCE. X-ray diffractometry study shows a shift toward the lower angle for the amorphous hump of the OCE. The OCE exhibits a ~123% increase in short-circuit current density, ~28% decrease in open-circuit voltage, and 29–64% decrease in charge-transfer and Warburg resistances, inferring the active role of the clay in improving the Li+ ion intercalation into and/or adsorption onto the TiO2. This has resulted in 54% increase in cell efficiency (~3.7% at solar irradiance of 100 mW cm−2).