Constructing novel binary Bi0.5Na0.5TiO3-based composite ceramics for excellent energy storage performances via defect engineering

Abstract

With the rapid development of sustainable and renewable technologies, electrostatic capacitors are now becoming a promising energy storage device. However, simultaneous achievement of large polarization and breakdown electric field of the electrostatic capacitors are an important technical challenge for improving energy storage density. In this article, we propose a surrogate approach by A-site defect engineering in (Bi0.47Sm0.03Na0.5-x)0.94Ba0.06TiO3 (BSNBT-x) ceramics to form two-phase structured composites ceramics, which contains of perovskite structured of the Bi0.5Na0.5TiO3 (BNT) with large polarization and Aurivillius phases of BaBi4Ti4O15 (BBT) generation high breakdown electric field. The phase-field simulations further demonstrate the Aurivillius phases BBT could significantly enhance breakdown electric field and retain high polarization. Accordingly, excellent recoverable energy density (Wrec ∼ 4.62 J/cm3) and discharged efficiency (η ∼ 79.1%) are achieved in (Bi0.47Sm0.03Na0.42)0.94Ba0.06TiO3 ceramics. Moreover, the corresponding ceramic also displays brilliant thermal endurance (20 °C to 220 °C), fatigue endurance (∼106 cycles), and frequency stability (1 Hz to 1000 Hz). These results could provide a general strategy to develop the energy-storage performances of ceramic capacitors for application in high-energy/power-density storage systems.