Boosting Energy Storage of AgNbO 3 ‐Based Capacitors by Constructing Low‐Atomic‐Displacement Region and M 2 ‐M 3 Two‐Phase Coexistence Strategy

ABSTRACT Dielectric capacitors with excellent energy‐storage performance are highly desirable for next‐generation advanced high/pulsed power capacitors that require miniaturization and integration. However, the low energy‐storage density arising from insufficient breakdown strength (BDS), inadequate maximum polarization ( P max ), and large remanent polarization ( P r ), remains a critical challenge for the practical application of dielectric capacitors. Herein, we propose a strategy to synergistically incorporate the M 2 ‐M 3 two‐phase coexistence and low‐atomic‐displacement (LAD) region into the AgNbO 3 system, thereby achieving high BDS, large P max and extremely low P r simultaneously. Ultrahigh U rec ∼ 17.1 J·cm −3 , excellent η ∼ 89% are achieved in the (Ag 1‐3 x Eu x )(Nb 0.7 Ta 0.3 )O 3 (Eu x ANT) multilayer ceramic capacitors (MLCCs) at x = 0.03, representing a breakthrough in the overall energy‐storage performance of lead‐free antiferroelectric (AFE) capacitors. This study not only develops a promising high‐performance lead‐free energy‐storage dielectric, but also offers a novel microstructural design strategy for the synergistic optimization of multiple energy‐storage parameters to improve the energy storage performance of AFE system.