Targeted polar entropy regulation enables superior energy-storage in tungsten bronze multilayer capacitors.

Peng, Haonan; Xie, Jiyang; Li, Jiaqi; Lu, Teng; Wei, Lingling; Hu, Wanbiao; Liu, Yun; Liu, Zhen et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

Tetragonal tungsten bronze (TTB) ceramics have emerged as promising candidates for dielectric energy storage due to their intrinsic multi-site architectures. However, the limited energy storage performance achieved so far remains insufficient for advanced electronic and pulsed power applications. Here, we propose a targeted polar-entropy regulation strategy via minor multi-element substitution at the polar-active B-sites, enabling precise modulation of polar displacements and weakened coupling among polar nanoregions. Atomic-scale characterization reveals site-dependent structural responses, which collectively reshape local polarization configurations and dipolar correlations. As a result, we demonstrate the feasibility of TTB ceramics for state-of-the-art multilayer energy-storage device applications, achieving an outstanding recoverable energy density (W<sub>rec</sub>) of 17.6 J·cm<sup>-3</sup> with a high efficiency of 96.8%, corresponding to a high figure of merit (W<sub>F</sub>) of 550. Moreover, excellent thermal stability (ΔW<sub>rec</sub> ≤ 2.0%) is achieved, and a highest W<sub>rec</sub> of 15.0 J·cm<sup>-3</sup> is maintained over a wide temperature range (-40 to 125 °C). This work offers new insights into polarization regulation and provides an effective pathway for developing high-performance energy storage dielectric capacitors.