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 3-10nm 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.