Improved energy storage performance achieved in Na_0.5Bi_0.5TiO₃-based ceramics with good thermal stability at low electric field

The primary challenges in relaxor ferroelectric ceramics are their high energy dissipation, low energy storage density, and reliance on strong electric fields, which hinder their excellent energy storage under low electric fields. Herein, we fabricated the (1−x)(0.75Na_0.5Bi_0.5TiO₃−0.25SrTiO₃)−xBi_2/3(Nb_0.5Al_0.5)O₃ ((1−x)NBST−xBNA) ceramics using the solid-state reaction method and comprehensively investigated phase structures, microstructure, dielectric properties, relaxation properties, breakdown properties, and energy storage properties through experimental and simulation methods. By utilizing modulable dielectric properties and fine grain size effect, the optimized component (x = 0.05) achieved an improved energy storage density of 2.32 J/cm³ and an outstanding efficiency of 91.7% at the low electric field of 180 kV/cm. Further, the outstanding stability in frequency (1–200 Hz) and temperature (20–140 °C) at 100 kV/cm was achieved in 0.95NBST-0.05BNA ceramics. This indicates that these materials have immense potential for high-power energy storage applications.