A strategy to achieve high energy storage performance under a relatively low electric field in NBT-based ceramics

Concerning the practical applications, dielectric capacitors with simultaneously high recoverable energy density (Wrec) and large energy storage efficiency (η) under a low electric field is imperative and challenging. Herein, a strategy of complex ions substitution is proposed to achieve the goal. The (1-x)(0.75Na0.5Bi0.5TiO3-0.25SrTiO3)-xLa(Mg2/3Ta1/3)O3 (NBST-xLMT) ceramics were fabricated through a solid-state reaction method. A significantly enhanced breakdown electric field (Eb) of 246.03 kV/cm is obtained in NBST-0.06LMT ceramics due to the refined average grain size (AGS), the enhanced band gap width and the inhibited oxygen vacancies by LMT doping. Furthermore, a high Wrec of 3.18 J/cm3and large η of 86% are concurrently achieved in NBST-0.06LMT ceramics under a relatively low electric field of 246 kV/cm. Meanwhile, the variations of (Wrec, η) under 170 kV/cm are less than 10% from 30 ℃ to 200 ℃, indicating an excellent thermal stability. Besides, the ceramics show a fast discharge rate of 155 ns by a charge-discharge measuring. In general, our results demonstrate the strategy of complex ions substitution is an effective way to achieve high energy storage performance under a relatively low electric field in NBT-based ceramics.