Synergistically enhanced energy storage performance of Bi0.47Na0.47Ba0.06TiO3-based relaxor ferroelectrics via dual engineering of dynamic nanodomains and defect regulation

Abstract

Ceramic capacitors are essential components in advanced electronics known for their high-power density and outstanding operational stability. However, simultaneously achieving a large reversible polarization response and high breakdown strength remains a critical challenge for developing next-generation energy storage devices. Herein, we report a defect-engineered Bi_0.47Na_0.47Ba_0.06TiO₃-based relaxor ferroelectric ceramic that realizes a good balance between these competing parameters. Through strategically constructing heterogeneous relaxor phases with weakly coupling and precisely controlled defect concentrations, we achieve a remarkable recoverable energy density of 13.6 J cm⁻³ at 760.0 kV cm⁻¹ with a high energy storage efficiency of 83.9%. The designed microstructure simultaneously enables strong field-induced polarization response while reducing hysteresis losses. Defect engineering enhances the resistivity and local electric field uniformity, leading to significantly improved dielectric breakdown strength. The optimized ceramic further demonstrates temperature/frequency-independent performance characteristics along with superior pulsed discharge capabilities. These findings provide a practical material design strategy for high-performance energy storage applications.