Effects of CuO additive on the dielectric property and energy-storage performance of BaTiO₃-SiO₂ ceramic-glass composite

CuO was used as an additive in BaTiO₃-SiO₂ ceramic-glass composites sintered from SiO₂-coated BaTiO₃ nanoparticles. The effects of the CuO content on the microstructure, phase composition, dielectric property, and energy-storage performance were investigated. The porosity of the composites was obviously reduced by the addition of CuO. All the composites suggested a perovskite phase. The maximal polarization, remnant polarization, and dielectric breakdown strength were strongly dependent on the CuO content. A maximal discharged energy density of 1.43 J/cm³ with a charge-discharge efficiency of 53% was achieved in the composite with 2.0 mol% CuO, which was enhanced by about 4 times as compared with that of the pure BaTiO₃-SiO₂ composite.