Enhanced ionic conductivity in PEO-LiClO4 hybrid electrolytes by structural modification

Poly(ethylene oxide)-LiClO4-TiO2 organic-inorganic hybrids were synthesized for Li-polymer battery electrolytes using sol-gel processing. The hybrids containing TiO2 component showed the uniform film formation and also increased ionic conductivity. The hybrid films containing 10 wt% TiO2 showed the smooth surface morphologies and also the highest ionic conductivity. The molecular-level hybrid formation between PEO and TiO2 components was identified using FTIR analyses. The hybrids containing TiO2-Al2O3 mixtures showed the enhanced ionic conductivity compared to those containing only TiO2 most probably due to the Lewis acidic group formation at the surface of Al2O3 components. The PEO-LiClO4-TiO2-Al2O3 hybrids showed high stability both in ionic conductivity and crystallinity. By the sol-gel processing two inorganic components were successfully introduced in the PEO matrix and high-performance solid electrolytes were achieved.