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

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 (Wrec) of 17.6 J·cm−3 with a high efficiency of 96.8%, corresponding to a high figure of merit (WF) of 550. Moreover, excellent thermal stability (ΔWrec ≤ 2.0%) is achieved, and a highest Wrec of 15.0 J·cm−3 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. The proposed targeted polar entropy regulation strategy, through precisely reshaping local polarization configurations, enables high energy density, efficiency, and thermal stability in tungsten bronze multilayer capacitors.