Improved Energy Storage Properties of Fine-Crystalline BaTiO3 Ceramics by Coating Powders with Al2O3 and SiO2

The multilayer structure of capacitor demands for fine grain size of dielectric ceramics in devices, because the thinner layer which needs ceramics with fine grain size is helpful in enlarging the capacitance. In this paper, the aqueous chemical coating method was utilized to modify the BaTiO3 particles. The fine‐crystalline BaTiO3 ceramics with an average grain size below 200 nm without abnormal grain growth by co‐coating Al2O3 and SiO2 has been prepared. The phase composition, microstructures of coated particles and ceramics, and dielectric properties were investigated. For samples containing 3 wt% of Al2O3 and 1 wt% of SiO2, the energy storage density is 0.725 J/cm3 and the efficiency of the ceramic samples can keep above 80%. The breakdown strength was improved to about 190 kV/cm.