Improved energy storage performance of NaNbO3-based antiferroelectrics by tuning polarizability and defect engineering

NaNbO 3 -based antiferroelectric ceramics are promising candidates for high-performance energy storage capacitors due to their environmental friendliness and low cost despite their current energy storage properties being inferior to those of their lead-based and AgNbO 3 -based counterparts. Typically, the antiferroelectric phase in NaNbO 3 ceramics is not stable and the characteristic double hysteresis loops are seldom observed. In this work, the antiferroelectricity was improved by reducing the polarizability, resulting in well-developed double hysteresis loops in 0.94NaNbO 3 –0.06(K 0.5 Bi 0.5 )SnO 3 ceramics. To further improve the energy storage properties, defect engineering was performed for 0.94NaNbO 3 –0.06(K 0.5 Bi 0.5 )SnO 3 by substituting Na + with La 3+ and introducing Nb vacancies. As a result, the stability of the field-induced ferroelectric phase was reduced, and the energy storage properties were enhanced. The strategy of combining polarizability design and defect engineering can be a promising approach for optimizing NaNbO 3 -based antiferroelectric ceramics.