NaNbO3-based ultra-high energy storage ceramics with linear polarization

Abstract

With the rapid advancement of electronic devices, the demand for capacitors with high energy storage steadily increases. Researchers are constantly searching for dielectrics that possess both high energy density and high energy efficiency. Using phase-field simulations, we found that cubic phase structures exhibiting linear polarization behavior have higher energy storage potential. Based on the simulation results, Sr_0.7Bi_0.2TiO₃ relaxors are introduced into the 0.88NaNbO₃–0.12Bi(Mg_2/3Ta_1/3)O₃ matrix to stabilize the cubic phase structure while enhancing polarization strength through orbital hybridization between Bi and O. Finally, a high-energy ball milling process is utilized to refine the grain size, fully exploiting its energy storage potential. In the 0.68NaNbO₃–0.12Bi(Mg_2/3Ta_1/3)O₃–0.20Sr_0.7Bi_0.2TiO₃ composition, an energy density of 10.1 J/cm³ and an energy efficiency of 88% are achieved, along with excellent temperature stability, frequency stability, and high fatigue resistance, these results are significant for improvement of energy storage dielectrics.