Significant enhancement in breakdown strength and energy density of the BaTiO3/BaTiO3@SiO2 layered ceramics with strong interface blocking effect

Abstract

The BaTiO3/BaTiO3@SiO2 (BT/BTS) ceramics with layered structure, where grain size was about 1–2μm in the BT layer while it was about 300–400nm in the BTS layer, were fabricated by the tape-casting and lamination method. With the increasing of SiO2 content in the BTS layer, the dielectric constant decreased gradually, and the breakdown strength was remarkably improved. Compared to the SiO2-added BaTiO3 bulk ceramics, the layered ceramics displayed significant enhancements in dielectric properties, breakdown properties and energy storage properties. The enhancement in dielectric properties was mostly attributed to the diluting effects created by this structure to SiO2. Based on the finite element analysis with the dielectric breakdown mode, it was regarded that the electric field redistribution and the interface blocking effect led to the enhancement of breakdown strength. Finally, the maximum energy density of 1.8J/cm3 was obtained at a breakdown strength of 301.4kV/cm for the BT/BTS3 ceramic.