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(Fe 1/3 Zn 1/3 Ti 1/3 )O 3 is added into NaNbO 3 lead-free antiferroelectric ceramics. The lower tolerance factor of Bi(Fe 1/3 Zn 1/3 Ti 1/3 )O 3 facilitates to achieve stable antiferroelectric phase in NaNbO 3 , and the introduction of various ions enhances the relaxor behavior. Consequently, the optimized 0.88NaNbO 3 − 0.12Bi(Fe 1/3 Zn 1/3 Ti 1/3 )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 μs. This study suggests that the incorporation of relaxor properties into antiferroelectric ceramics is a beneficial route to boost the dielectric energy storage capability.