Enhanced capacitance performance of Al₂O₃-TiO₂ composite thin film via sol-gel using double chelators

Titanium dioxide (TiO2) is usually introduced into dielectric layer of aluminum electrolytic capacitor to enhance capacitance performance via forming Al2O3-TiO2 composite film. However, there is a big obstacle caused by high crystallization temperature of TiO2 to capacitance enhancement. In present work, a facile route was proposed to synthesize crystalline TiO2 with the size of 3-10 nm at room temperature using lactic acid (LA) and acetylacetone (Acac) as double chelators. After being introduced into the surface of etched aluminum foils as dielectric layer, TiO2 boosted the specific capacitance by about 24% compared to that without TiO2, and about 11% compared to that with TiO2 using lactic acid as only chelator.