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_0.5Zr_0.5)O₃ was introduced into the (Bi_0.47La_0.03Na_0.5)_0.94Ba_0.06TiO₃ 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/cm³ 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 10⁴ cycles. These findings demonstrated that the (Bi_0.47La_0.03Na_0.5)_0.94Ba_0.06TiO₃-Sr(Ti_0.5Zr_0.5)O₃ lead-free ceramic fabricated by a tape-casting technique exhibits significant potential for use in high-performance pulsed power systems.