Remarkably enhanced energy-storage density and excellent thermal stability under low electric fields of (Na0.5Bi0.5)TiO3-based ceramics via composition optimization strategy

High energy density and high thermal stability of energy-storage properties (ESP) under low electric fields are extremely crucial for the application of dielectric ceramics in miniaturized equipment. In present work, we use a composition-optimization approach to break the long-range ferroelectric order and modulate polar nanoregions (PNRs) in the local structure of (1-x)[0.7(Na0.5Bi0.5)TiO3-0.3(Sr0.7Bi0.2)TiO3]-xBi(Mg0.5Ti0.5)O-3 system. The large P-max value is maintained due to the existence of Bi ions in both the matrix and dopants. As a result, a high W-rec of 3.03 J/cm(3) together with a moderate. of 79.5 % was obtained in x = 0.05 sample at a low electric field of 200 kV/cm. Meanwhile, the high Wrec (2.41-2.52 J/cm(3)) and excellent thermal stability of ESP (Wrec varying less than 4.3 % and. > 90 %) from 50 degrees C to 200 degrees C at 150 kV/cm were also observed. The current system will be a promising candidate in energy-storage capacitor applications under low-fields and high-temperature.