Improved energy storage in antiferroelectric AgNbO3-modulated 0.925Bi0.5Na0.5TiO3-0.075BaTiO3 relaxor ferroelectric ceramics

In this report, antiferroelectric AgNbO3-modified (1-x)(0.925Bi(0.5)Na(0.5)TiO(3)-0.075BaTiO(3))-xAgNbO(3) (x = 0-0.2) relaxor-ferroelectric ceramics were studied to optimize energy density and storage efficiency. Dielectric properties and microstructure were analyzed to explore the influence of antiferroelectric AgNbO3 (AN) in energystorage performance of 0.925Bi(0.5)Na(0.5)TiO(3)-0.075BaTiO(3) (BNBT) ceramics. By substituting proper AN concentrations (x = 0.15), dielectric breakdown strength (BDS) can be effectively increased, while remanent polarization (Pr) and coercive field (Ec) were evidently reduced. The optimal recoverable energy density (W-rec) of 3.92 J/cm(3) and storage efficiency (eta) of 70% are respectively achieved for x = 0.1 (at E = 180 kV/cm) and x = 0.05 (at E = 110 kV/cm). Temperature-dependent dielectric permittivities show that 0.1 similar to 0.15 AN-doped BNBT ceramics maintain low dielectric losses (tan delta < 0.1%) with a stable temperature coefficient of capacitance (TCC), which meets the X7R specification. This work demonstrates that antiferroelectric AN-doped BNBT relaxorferroelectric ceramics are suitable for using in high-density energy storage.