Ultrahigh energy-storage dielectric ceramics via synergistic polymorphic nanodomain and defect design.

Zhang, Min; He, Yuzhou; Pan, Hao; Zhang, Qinghua; Jing, Peixuan; Guo, Weijia; Cai, Hongdong; Nan, Ce-Wen et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

Dielectric capacitors are critical for advanced energy storage due to their ultrahigh power density and rapid charge-discharge rates. However, their application is limited by the low energy density. Here, we design a BaTiO<sub>3</sub>-(K<sub>0.5</sub>Na<sub>0.5</sub>)NbO<sub>3</sub>-(Bi<sub>0.5</sub>Na<sub>0.5</sub>)Ti<sub>0.9</sub>Zr<sub>0.1</sub>O<sub>3</sub> solid-solution system through synergistic polymorphic nanodomain engineering and defect optimization. By engineering polymorphic nanodomains with coexisting rhombohedral, orthorhombic, tetragonal, cubic nanodomain in 1.0-2.0 nm size and defect design with reduces oxygen vacancy concentration and forms defect complexes, we achieve an ultrahigh energy density of 18.7 J cm⁻<sup>3</sup> with remarkable efficiency of 92.1% in multilayer ceramic capacitors, along with excellent cycling stability (>10<sup>7</sup> cycles) and thermal stability (<±5% from 25 to 150 °C). In this work, we provide a paradigm for designing high-performance dielectric capacitors through the synergistic manipulation of domain structures and defect engineering.