Enhanced energy storage properties of ZrO₂-doped (Na_0.5Bi_0.5)_0.4Sr_0.6TiO₃ Pb-free relaxor ferroelectric ceramics

(Na_0.5Bi_0.5)_0.4Sr_0.6Ti_1-xZr_xO₃ relaxor ferroelectric ceramic were prepared by a traditional ceramic preparation process introducing Zr⁴⁺ at the B-site. It was observed that introducing an appropriate amount of Zr⁴⁺ ions into the NBST matrix can improve the energy storage efficiency. (Na_0.5Bi_0.5)_0.4Sr_0.6Ti_0.5Zr_0.5O₃ shows excellent energy storage density up to 2.83 J/cm³, and excellent efficiency (83.90 %) at 220 kV/cm. A single layer ceramic capacitor (SLCC) was also prepared by the tape casting technique for multilayer ceramic capacitors (MLCCs) to further enhance the energy storage performance. The recoverable energy storage capacity is increased to 4.52 J/cm³ and the efficiency is 70.02 % at 460 kV/cm. Moreover, it still has a relatively stable energy storage performance after 10⁵ cycles of charge and discharge. This sample has exhibited outstanding energy storage performance, fatigue resistance, and charge/discharge performance and has great potential value in practical applications.