Capacitive energy storage performance of lead-free sodium niobate-based antiferroelectric ceramics

Ceramic-based capacitors have attracted great interest due to their large power density and ultrafast charge/discharge time, which are needful properties for pulsed-power devices. Antiferroelectric ceramics normally show ultrahigh energy density and relatively low efficiency, which is ascribed to the electric field-induced antiferroelectric-ferroelectric phase transition. This work reports that the perovskite end-member Bi(Fe1/3Zn1/3Ti1/3)O-3 is added into NaNbO3 lead-free antiferroelectric ceramics. The lower tolerance factor of Bi(Fe1/3Zn1/3Ti1/3)O-3 facilitates to achieve stable antiferroelectric phase in NaNbO3, and the introduction of various ions enhances the relaxor behavior. Consequently, the optimized 0.88NaNbO(3 )- 0.12Bi(Fe1/3Zn1/3Ti1/3)O-3 ceramics exhibit a large recoverable energy density of 6.8 J/cm(3) and a high efficiency of 82% under 49 kV/mm, as well as discharge energy density of 4 J/cm(3) and charge/discharge time of 5 & mu;s. This study suggests that the incorporation of relaxor properties into antiferroelectric ceramics is a beneficial route to boost the dielectric energy storage capability.