Enhanced energy storage performance of silver niobate-based antiferroelectric ceramics by two-step sintering mothed

AgNbO₃ lead-free antiferroelectric (AFE) ceramics are attractive candidates for energy storage applications and power electronic systems. In this study, AgNbO₃ ceramics are synthesized by single-step sintering (SSS) and two-step sintering (TSS) processes under oxygen-free atmosphere, and their energy storage performance is compared. The prepared ceramic materials show characteristic AFE double hysteresis (P–E) loop and excellent energy storage performance. Especially, the AgNbO₃ ceramic materials prepared by TSS achieve a maximum recoverable storage density (W_rec) of 2.32 J/cm³ under 150 kV/cm by reducing the remnant polarization (P_r), which is 36% higher than that of the material prepared by SSS (1.7 J/cm³). Furthermore, the AgNbO₃ ceramic exhibits outstanding temperature stability. Specifically, the variation in W_rec is less than 6% when the temperature increases from 30 to 120 °C. These remarkable properties are mainly attributed to the high relative density, small grain size, and excellent energy storage performance of the ceramic prepared by TSS, which extends the particle rearrangement time at low temperature and promotes the uniform grain growth at high temperature. Overall, this study can serve as a useful reference for the development of capacitors in pulsed power systems.