Enhancement of energy-storage properties in BaTiO₃-based relaxor ferroelectrics via introducing (Bi_0.5Na_0.5)_0.7Sr_0.3TiO₃

Dielectric energy-storage ceramic materials with fast charging and discharging times and high reliability have almost irreplaceable applications in fields such as high-energy pulsed-power technology. To mitigate the environmental pollution caused by lead-containing dielectric energy-storage ceramics, lead-free dielectric energy-storage materials have become the focus of current research. In this work, BaTiO₃-Bi(Zn_0.5Ti_0.5)O₃ (BT-BZT) was combined with (Bi_0.5Na_0.5)_0.7Sr_0.3TiO₃ (BNST) to fabricate (1-x)(0.9BT-0.1BZT)-xBNST solid solutions (x = 0.00, 0.05, 0.10, 0.15, and 0.20) via conventional solid-state reaction methods. Through reasonable component optimization, a high recoverable energy-storage density (W_rec) of 3.5 J/cm³ and large efficiency (η) of 90.8% were achieved in the sample with BNST concentration of x = 0.15. Meanwhile, the sample exhibited an ultrafast discharge time of ~ 53.0 ns over the range of ambient temperature to 120 °C. This exceptional energy-storage performance indicates that the 0.85(0.9BT-0.1BZT)-0.15BNST ceramic is a promising candidate for the dielectric energy storage in a high-power pulse capacitor.