B-site entropy tuning assisted Na0.5Bi0.5TiO3-based ceramics with superior energy storage performance

High-performance lead-free ceramic capacitors are the core composition of next-generation pulsed power devices. In this study, an effective approach of adding the high entropy end-member of Bi(Mg0.2Ti0.2Al0.2Ni0.2Zr0.2)O3 (BMTANZ) into the (Na0.5Bi0.47La0.03)0.94Ba0.06TiO3 (NBLBT) ceramic to optimize energy storage properties through adjusting B-site entropy is proposed. Consequently, with the configuration entropy (∆Sconfig) raises from 0.98 R to 1.41 R, the 0.88NBLBT-0.12BMTANZ ceramic gain outstanding energy storage properties (Wrec = 4.06 J/cm3, η = 83.7 %) under 300 kV/cm. The superior energy storage capability can be ascribed to the inhibition of grain size and interfacial polarization resulting from the improvement of B-site entropy, and the optimization of dielectric relaxor behavior. Additionally, the prominent thermal and frequency stability over the range of 25–125 °C and 1–100 Hz are realized in 0.88NBLBT-0.12BMTANZ ceramic. Remarkably, the corresponding sample possesses brilliant charge-discharge characteristics (power density PD ∼ 43.2 MW/cm3, discharge rate t0.9–57.1 ns). These results demonstrate that the novel component of 0.88NBLBT-0.12BMTANZ has broad application prospects in advanced energy storage capacitors.