Ultrahigh energy storage density and charge‐discharge performance in novel sodium bismuth titanate‐based ceramics

Abstract Lead‐free ferroelectric ceramics are very suitable for electrostatic energy storage capacitors due to their outstanding characteristics of high charge‐discharge speed, high power density, and environmental friendliness. Herein, a novel material system as (1− x )Na 0.5 Bi 0.5 TiO 3 ‐ x CaZr 0.5 Ti 0.5 O 3 (NBT‐CZT, x = 0, 0.05, 0.10, 0.12, 0.15, and 0.20) was designed and prepared for dielectric energy storage ceramics. It demonstrated that the CZT additives induced a phase transition for the NBT ceramics, from ferroelectric to relaxor ferroelectric. In particular, extremely high stored energy storage density (6.92 and 5.37 J/cm 3 ), high recoverable energy storage density (4.77 and 4.37 J/cm 3 ), and moderate efficiency (69.0% and 81.4%) were achieved in both the samples of x = 0.12 and x = 0.15, respectively. The ceramics exhibited excellent stability of energy storage performance covering a wide temperature (25°C–200°C) and frequency (0.5–50 Hz) range, and also fatigue cycles up to 10 5 . Additionally, the NBT‐CZT ceramics had a fast discharge speed ( t 0.9 < 100 ns) and high power density (24.2 MW/cm 3 , E = 100 kV/cm, x = 0.15), and the charge‐discharge process remained stable even when the measured temperature was up to 160°C. Therefore, the NBT‐CZT ceramics have the potential to be utilized in electrostatic energy storage applications.