Simultaneously Enhanced Energy Storage Density and Efficiency in BNT-Based Lead-Free Ceramics

Lead-free ceramics are critical for the development of pulsed power systems because of their exceptional energy storage performance, superior power density, and fast charge–discharge capabilities. However, the relatively low energy density greatly restricts advancements in lightweight and miniaturized devices. To tackle this issue, the Sr(Ti 0.5 Zr 0.5 )O 3 was introduced into the (Bi 0.47 La 0.03 Na 0.5 ) 0.94 Ba 0.06 TiO 3 matrix to reduce the grain size, enhance bandgap, and promote the formation of polar nanoregions. These changes collectively contributed to a lower remnant polarization and an improved maximum applied electric field. Meanwhile, the tape-casting technique was employed to ensure a uniform and dense microstructure, further enhancing the maximum applied electric field. Interestingly, the optimized ceramics exhibit outstanding energy storage performance, with a recoverable energy density of 6.05 J/cm 3 alongside an efficiency of approximately 90% at an applied electric field of 560 kV/cm. Additionally, the energy storage characteristics display excellent stability across a broad temperature range of 25–160 °C and up to 10 4 cycles. These findings demonstrated that the (Bi 0.47 La 0.03 Na 0.5 ) 0.94 Ba 0.06 TiO 3 –Sr(Ti 0.5 Zr 0.5 )O 3 lead-free ceramic fabricated by a tape-casting technique exhibits significant potential for use in high-performance pulsed power systems.