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

•Multi-scale synergistic design was proposed in AgNbO3-based ceramics.•High Eb up to 702 kV/cm was obtained in Bi & Sr doped AgNbO3 ceramics.•Both antiferroelectric stability and polarization were improved via Bi & Sr doping.•Wrec and η reached 7.9 J/cm3 and 75.5 % in Bi & Sr doped AgNbO3 ceramics.•Wrec and η in present work are among the top values of AgNbO3-based ceramics.