Simultaneous enhancement of breakdown strength, recoverable energy storage density and efficiency in antiferroelectric AgNbO3 ceramics via multi-scale synergistic design

Dielectric capacitors with large power densities are indispensable components in advanced electric and electronic devices. However, the limited energy density and efficiency are challenging and badly restrict their utilization in practice. Here, fine-grains, increased resistivity and activation energy, optimized maximum polarization, and benign relaxation features are simultaneously achieved in AgNbO 3 -based ceramics via a multi-scale synergistic design, combining hydrothermal methods with Bi and Sr doping. As a result, we synergistically realized high breakdown strength of 702 kV/cm, large recoverable energy storage density of 7.9 J/cm 3 and benign energy efficiency of 75.5 % in (Ag 0.80 Bi 0.04 Sr 0.04 )NbO 3 ceramics. Furthermore, excellent temperature-, frequency-, cycling-stability and ultrahigh discharge energy density of 5.6 J/cm 3 were simultaneously achieved in (Ag 0.80 Bi 0.04 Sr 0.04 )NbO 3 ceramics, indicating a promising candidate for competitiveness and development in advanced high-power applications.