Enhanced Energy Storage Performance in Na0.5Bi0.5TiO3-Based Relaxor Ferroelectric Ceramics via Compositional Tailoring

Owing to the high power density, excellent operational stability and fast charge/discharge rate, and environmental friendliness, the lead-free Na0.5Bi0.5TiO3 (NBT)-based relaxor ferroelectrics exhibit great potential in pulsed power capacitors. Herein, novel lead-free (1 -x)(0.7Na(0.5)Bi(0.5)TiO(3)-0.3Sr(0.7)Bi(0.2)TiO(3))-xBi(Mg0.5Zr0.5)O-3 (NBT-SBT-xBMZ) relaxor ferroelectric ceramics were successfully fabricated using a solid-state reaction method and designed via compositional tailoring. The microstructure, dielectric properties, ferroelectric properties, and energy storage performance were investigated. The results indicate that appropriate Bi(Mg0.5Zr0.5)O-3 content can effectively enhance the relaxor ferroelectric characteristics and improve the dielectric breakdown strength by forming fine grain sizes and diminishing oxygen vacancy concentrations. Therefore, the optimal W-rec of 6.75 J/cm(3) and a eta of 79.44% were simultaneously obtained in NBT-SBT-0.15BMZ at 20 degrees C and 385 kV/cm. Meanwhile, thermal stability (20-180 degrees C) and frequency stability (1-200 Hz) associated with the ultrafast discharge time of similar to 49.1 ns were also procured in the same composition, providing a promising material system for applications in power pulse devices.