High breakdown strength and energy storage density of Er_(0.02)Sr_(0.97)TiO_3@MgO_2-Al_2O_3-SiO_2 ceramics with core-shell structure sintered in oxygen atmosphere

摘要

Effects of different sintering atmospheres (O_2 and air) on the energy storage properties and dielectric characteristics were systematically investigated for 2MgO-2Al_2O_3-5SiO_2 (MAS)-coated Er_(0.02)Sr_(0.97)TiO_3 (EST) ceramics. The core-shell structure was formed by the sol-precipitation method. The ceramic sintered in O_2 features fine grain, excellent frequency stability, low leakage current, high dielectric breakdown strength (BDS), and high energy storage density (W_(reco)). Compared with air-sintered ceramics, the dielectric DC breakdown strength of ceramic sintered in oxygen atmosphere has been enhanced significantly from 375 to 590 kV/cm. Besides, the maximum W_(reco) of 2.01 J/cm~3 and efficiency of 86.2% were obtained at 460 kV/cm, which demonstrated that the core-shell structure and atmosphere sintering provide an instructive strategy for the design of high energy storage materials.