ABSTRACT Dielectric capacitors are critical for pulsed power systems, yet their energy storage performance (ESP) requires further enhancement. While high‐entropy design improves breakdown strength ( E b ), it often stabilizes a non‐polar phase, limiting polarization ( P m ) and restricting high ESP to impractically high electric fields. Here, we propose an inverse high‐entropy design strategy to overcome this limitation. Using the quasi‐linear high‐entropy ceramic Bi 1/6 Na 1/6 Sr 1/6 Ca 1/6 Li 1/6 La 1/6 TiO 3 (BNSCLLT) as a matrix, we incorporated the classical ferroelectric BaTiO 3 (BT) to precisely regulate the polar structure. Introducing BT successfully induced a weakly polar tetragonal phase within the primarily cubic matrix, promoting polar nanoregions and optimizing the polarization response. This strategy effectively balances a significant increase in P m with a controlled reduction in E b . Consequently, the 0.7BNSCLLT‐0.3BT and 0.6BNSCLLT‐0.4BT compositions achieved superior performance with W rec ∼ 10.9 J/cm 3 , η ∼ 88% at 600 kV/cm and W rec ∼ 11.6 J/cm 3 , η ∼ 86% at 580 kV/cm, respectively. Notably, the 0.5BNSCLLT‐0.5BT composition also attained excellent ESP ( W rec ∼ 9.8 J/cm 3 , η ∼ 80%) at a moderate field of 475 kV/cm. This work demonstrates the efficacy of the inverse high‐entropy design in achieving high‐performance energy storage across both high and moderate electric fields, offering a new paradigm for developing advanced dielectric materials.
Zhao et al. (Mon,) studied this question.