High energy storage performance in (Ag _0.94 La _0.02 )(Nb _0.85 Ta _0.15 )O ₃ ‐modified BNT‐based ceramics at lower electric field

Abstract Dielectric capacitors typically require high electric fields to achieve excellent energy storage density, which limits the integration, miniaturization, and lifespan of energy storage devices. Therefore, it is essential to obtain good energy storage properties at a lower electric field. In this study, (Ag 0.94 La 0.02 )(Nb 0.85 Ta 0.15 )O 3 (ALNT)‐modified (Bi 0.5 Na 0.5 )TiO 3 ‐based ceramics with improved energy storage characteristics were designed and prepared. The introduction of ALNT is conducive to optimizing the polarization, adjusting the phase composition, disrupting the long‐range ferroelectric ordering, and enhancing the dielectric relaxation behavior, leading to an increase in the polarization difference. Accordingly, superior recoverable energy storage density of 3.07 J/cm 3 and high efficiency of 82.7% are synchronously realized under a lower electric field of 150 kV/cm in a 5 mol% ALNT system. In addition, the corresponding sample exhibits wide thermal (40–100°C) and frequency (10–100 Hz) stability and good charge–discharge properties. This study provides a new candidate material for advanced dielectric capacitors that can be applied in lower electric fields.