Effect of holding time on microstructure, ferroelectric and energy-storage properties of Pb0.925La0.05Zr0.95Ti0.05O3@SiO2 ceramics

•(PLZT@SiO2) core-shell structure ceramic materials are synthesized by the sol-gel combination with the solid-phase method.•Its dielectric constant can be adjusted by holding time.•The surface of PLZT coated with SiO2 can increase the breakdown electric field (BDS) and thus increase the energy density. Antiferroelectric materials are considered promising energy storage materials because they have excellent energy density during the antiferroelectric phase transition. Herein, Pb0.925La0.05Zr0.95Ti0.05O3@SiO2 (PLZT@SiO2) core-shell structure ceramic materials were synthesized by combing sol-gel method with conventional solid-phase method. The effect of holding time (3 h, 6 h, 9 h, 12 h) on the electrical properties and energy storage properties of PLZT@SiO2 ceramics were investigated. TEM results indicate the formation of a core-shell structure. Transmission electron microscope (TEM) reveals the formation of core-shell structure. X-ray diffraction (XRD) obtained clear tetragonal perovskite structure PLZT and SiO2 phase. The phase transition temperature of PLZT@SiO2 ceramics is between 222 °C and 225 °C, and its dielectric constant can be adjusted by the holding time. The PLZT with surface coated SiO2 can increase the breakdown electric field (BDS) and thus increase the energy density. When the holding time is 9 h, the breakdown electric field is as high as 156.84 kV/cm, and the recoverable energy density (Wre) is 1.92 J/cm3, which is mainly determined by its high density and breakdown electric field.