The polarization contribution and effect mechanism of Ce-doped 0.65BaTiO3-0.35Sr0.7Bi0.2TiO3 Pb-free ferroelectric ceramics for dielectric energy storage

Abstract In the current study, a series of CeO2-doped (x = 0.01, 0.015, 0.02, 0.025 mol) ceramic samples were prepared, and the valence of Ce in the perovskite was analyzed in detail, revealing the polarization contribution and effect mechanism of the doped Ce element in the 0.65BaTiO3–0.35Sr0.7Bi0.2TiO3 ceramic. The phase structure and electrical stored energy performance of the resulting ceramics were also characterized. It was found that adding an appropriate amount of CeO2 to BaTiO3 was helpful for improving the relaxor behavior, promoting electric storage, and releasing ceramic materials. Particularly, the electric breakdown strength of the 0.02Ce-doped specimen reached 330 kV/cm, and the corresponding density and efficiency were 2.57 J/cm3 and 81.30%, respectively. In addition, doping with Ce caused the ceramics to exhibit good stability at frequencies of 1–300 Hz and over a temperature range of 30–150 °C. A high current density (CD) and power density (PD) were obtained in charge–discharge tests.