Electronic band and core-shell structure engineering enables ultrahigh energy storage in high-entropy ceramics.

Li, Yunting; Li, Peng; Huang, Haihua; Bai, Hairui; Xu, Fei; Hao, Jigong; Fu, Peng; Du, Juan et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

Relaxor ferroelectric ceramics are promising energy-storage candidates for high-power electronic systems owing to their high energy density and fast charge-discharge speed. However, achieving ultrahigh energy density still poses challenges due to the inherently inverted coupling relationship between polarization (P) and breakdown electric field (E<sub>b</sub>). Here, we propose a high-entropy strategy to decouple polarization from breakdown electric field. The high-entropy design exerts a triple effect, which involves flattening electronic band to restrict the transport of charge carriers, driving the formation of core-shell heterostructure to suppress electrical breakdown, and stabilizing polymorphic polar phases to promote polarization rotation. The triple synergy effect led to an ultrahigh E<sub>b</sub> and a maximized polarization disparity (ΔP = P<sub>m</sub> - P<sub>r</sub>). As a result, the high-entropy ceramics exhibit an ultrahigh recoverable energy density (W<sub>rec</sub>) of 10.23 ± 0.99 J/cm<sup>3</sup> and a satisfactory efficiency (η) of 85.44% ± 3.34%, alongside good cycling reliability and temperature stability. This work provides an innovative design paradigm for achieving excellent energy storage performance of dielectric capacitors.