Realizing high energy storage performance in (Bi0.5Na0.5)0.7Sr0.3TiO3 ceramics via phase structure adjustment

Abstract

In recent years, ceramic dielectric capacitors have received extensive attention in pulsed power systems because they are pollution-free and environmentally friendly. However, the low energy storage density (W_rec) of ceramics persists as a significant impediment, which seriously limits their practical applications. In this paper, (1− x)(Bi_0.5Na_0.5)_0.7Sr_0.3TiO₃–xLa(Mg_2/3Nb_1/3)O₃ [abbreviated as (1− x)BNST–xLMN] lead-free ceramic capacitors, with good energy storage performance (ESP), are prepared by a solid-phase reaction method. The effects of different LMN contents on the phase structure, microstructure, dielectric properties, and energy storage performance of BNST ceramics were systematically studied. The breakdown field strength (E_b) of the matrix was improved by adding La to alleviate the premature saturation polarization and low E_b of the matrix. At x = 0.05, the ceramic exhibits decent ESP, with a recoverable W_rec of 7.26 J cm⁻³, and an energy storage efficiency (η) of 85.54%, as well as excellent temperature and frequency stability.