Effect of introducing Sr2+/Hf4+ on phase structures, bandgaps, and energy storage performance in Bi0.47Na0.47Ba0.06TiO3-based ferroelectric ceramic

Abstract

Dielectric energy storage ceramic capacitors have garnered wide attraction in recent years due to their splendid integrated energy storage properties. However, difficulties in obtaining splendid integrated properties limit their industrial application. This work achieved splendid integrated energy storage properties by doping Sr2+/Hf4+ into the Bi0.47Na0.47Ba0.06TiO3 ceramics. The R3c and P4bm phases were simultaneously induced and the short-range ordered polar nanoregions were formed, thereby generating a large polarization D-value by maintaining the large maximum polarization of the Bi0.47Na0.47Ba0.06TiO3 ceramics and greatly reducing the remnant polarization. By increasing both the density of the grain boundaries and the difficulty of electrons leaping out of the valence band to the conduction band, the breakdown electric fields of the ceramics were greatly improved. Eventually, a high Wrec of 5.83 J/cm3, a moderate η of 83.67%, a stable frequency (Wrec ≈ 2.84 ± 2.1% J/cm3, η ≈ 80.7 ± 2.8%, 1–200 Hz), excellent temperature stability (Wrec ≈ 2.89 ± 1.4% J/cm3, η ≈ 83.7 ± 1.0%, 20–140 °C), and a fast discharge rate (8 μs) were simultaneously obtained in the 0.8Bi0.47Na0.47Ba0.06TiO3-0.2SrHfO3 relaxor ferroelectric ceramics. These results suggested that the co-doping of A/B sites could significantly improve the energy storage properties of the Bi0.47Na0.47Ba0.06TiO3 ceramics. Furthermore, the excellent integrated properties indicate that the 0.8Bi0.47Na0.47Ba0.06TiO3-0.2SrHfO3 ceramics are expected to meet the application requirements of dielectric capacitors under complex conditions in the future.