Achieving excellent energy storage properties of Na0.5Bi0.5TiO3 - based ceramics by using a two-step strategy involving phase and polarization modification

Abstract Na0.5Bi0.5TiO3-based ceramic specimens have been extensively investigated as ferroelectric materials. After being doped with CaTiO3, the resulting Na0.5Bi0.5TiO3-based ceramics exhibit relaxor characteristics, and improved energy storage density and efficiency. Based on these above results, CeO2 was further employed to modify the polarization of the 0.85Na0.5Bi0.5TiO3-0.15CaTiO3 matrix ceramic to achieve better energy storage performance. The effective energy storage density was enhanced from 1.93 to 2.53 J/cm3 by using the appropriate doping concentration of CeO2. Grain refinement effect can effectively enhance the electric-field strength from approximately 190 to 230 kV/cm. In particular, when doped with 2% CeO2, the energy storage efficiency of the sample was maintained at approximately 90% at 30 °C-150 °C and at approximately 80% in the frequency range of 0.2–200 Hz. This combination has very excellent temperature stability and frequency stability, making it a promising candidate for energy storage applications.