Lead‐free Ag _{1−3 <i>x</i>} La _<i>x</i> NbO ₃ antiferroelectric ceramics with high‐energy storage density and efficiency

Abstract

Abstract Environmentally benign lead‐free bulk ceramics with high recoverable energy density ( W rec ) are very attractive in advanced pulsed power capacitors. In this work, composition engineering was adopted by La 3+ modification to improve the energy storage performance of Ag 1−3 x La x NbO 3 ceramics. It was found that the antiferroelectric (AFE) phase was stabilized after La 3+ substitution, as a result of the reduced tolerance factor t . Significant improvement of W rec and energy storage efficiency ( η ) were achieved with value of 3.12 J/cm 3 and 0.63 for x = 0.02 at an electric field of 230 kV/cm, more than 1.5 times the value of pure AgNbO 3 ( W rec = 1.9 J/cm 3 , η = 0.40). The excellent energy storage properties are resulted from the increased antiferroelectric‐ferroelectric phase transition electric field ( E F ), ferroelectric‐antiferroelectric phase transition electric field ( E A ), and breakdown electric field ( E b ). The enhanced E b was ascribed to the decreased grain size and increased electrical resistivity upon La 3+ modification. The feature makes Ag 1−3 x La x NbO 3 a potential candidate for energy storage applications.