Synergic Enhancement of Energy Storage Density and Efficiency in MnO 2 -Doped AgNbO 3 @SiO 2 Ceramics via A/B-Site Substitutions.

Dielectric energy storage devices with high power density show great potential in applications of smart grids, electrical vehicles, pulsed power weapons, and so on. However, their limited recoverable energy density badly restricts their utilization and harms the miniaturization, portability, and integration of electronics. Herein, equivalent amounts of Bi 2 O 3 and Sc 2 O 3 were introduced to improve the energy storage property of 0.10 wt % MnO 2 -doped AgNbO 3 @SiO 2 ceramics by simultaneously enhancing the maximum polarization, breakdown strength, and relaxation feature. It is particularly interesting that the AgNbO 3 -based ceramics with 4 mol % Bi 2 O 3 and Sc 2 O 3 demonstrate the recoverable energy storage density of 5.9 J/cm 3 with the energy storage efficiency of 71%, exhibiting 1.9 and 1.4 times enhancement compared to 0.10 wt % MnO 2 -doped AgNbO 3 @SiO 2 ceramics. In addition, the benign energy storage performance can be maintained at elevated temperatures and frequencies and up to 10 5 cycling, indicating great potential in advanced high-power applications.