Energy-storage properties of ternary system NaNbO3-LaFeO3-Sr(Fe0.5Nb0.5)O3 ceramics

Capacitors with dielectrics as media have drawn great attention for the energy-storage application of high-power electronic systems. Sodium niobate (NaNbO 3 ) is the famous antiferroelectric with more phases and phase transitions, but without perfect recoverable energy storage density W rec and efficiency η . Herein, the relaxor ternary NaNbO 3 -LaFeO 3 -Sr(Fe 0.5 Nb 0.5 )O 3 ceramics are constructed by employing domain and domain wall engineering for integrating the merits of relaxors and antiferroelectrics. The phase transforms from orthorhombic P bcm to P mmn, and relaxor characters are revealed by the rotations of domains and the movements of domain walls. Particularly important, 0.88NaNbO 3 -0.096LaFeO 3 -0.024Sr(Fe 0.5 Nb 0.5 )O 3 demonstrates the great properties of high W rec as 2.645 J/cm 3 and super η as 80.7% at 230 kV/cm, less than the large electric breakdown strength E b of 235 kV/cm. These results suggest that NaNbO 3 -based ceramics are suitable for advanced capacitors, and the feasible strategy of domain and domain wall engineering is developed to provide novel energy storage dielectrics.