Enhanced energy storage performance in Na(1-3x)BixNb0.85Ta0.15O3 relaxor ferroelectric ceramics

Abstract High-performance lead-free dielectric containers have excellent energy storage performance such as higher power density and energy density. While being eco-friendly materials, lead-free dielectric materials are more suitable for pulse power systems than other dielectric materials. In this study, Ta5+and Bi3+ ions were introduced into the A site and B site of the NaNbO3 matrix. The introduction of Bi3+ ions induced the formation of a vacancy in the A site, yielding Na(1-3x)BixNb0.85Ta0.15O3 (NBNT, x = 0.05, 0.08, 0.11, 0.14) ceramics. The recoverable energy density (Wrec) and the energy storage efficiency (η) were highest for the Na0.67Bi0.11Nb0.85Ta0.15O3 ceramic, with values of 3.37 J/cm3 and 89% respectively. Batteries employing the Na0.67Bi0.11Nb0.85Ta0.15O3 ceramic achieved a current density of 830.4 A/cm2, an energy density of 49.8 MW/cm3 and 60.2 ns discharge time. These results show that the Na0.67Bi0.11Nb0.85Ta0.15O3 ceramic is an effective energy storage material with broad application prospects.