High-Entropy Chemical Composition Design for Ultrahigh Capacitive Energy Storage

Superior energy-storage performance is imperative for next-generation electronics and pulsed power systems. However, in lead-free dielectric ceramics, achieving synergistic optimization of energy storage performance remains a critical challenge. The central obstacle lies in the simultaneous enhancement of both energy density ( W rec ) and efficiency ( η ). Herein, a high-entropy lead-free Bi 0.32 Na 0.32 Ba 0.32 La 0.04 TiO 3 -NaNbO 3 ceramics system is designed, guided by phase-field simulations and a strategic chemical composition approach. The synergistic effect of La-donor doping and NaNbO 3 addition induces local random fields and local random stresses, stabilizing multiphase ultrasmall polar nanoregions. Benefiting from these features, an ultrahigh energy storage performance of W rec ≈ 12.4 J cm − 3 and η ≈ 82.6% is realized under the applied field 790 kV cm −1 . Furthermore, a large W rec of ≈6.2 J cm −3 and a high η ≈ 85.8% with less than 5% variation across a broad temperature (30–150 °C) range are highly promising results for lead-free ceramics. This study marks a significant advancement in the energy storage performance and also provides a paradigm for the development of new lead-free ceramics for the next generation of pulsed power applications.