High‐Entropy Tungsten Bronze Ceramics for Large Capacitive Energy Storage with Near‐Zero Losses

• Published in: Advanced functional materials Vol. 34; no. 49
• Main Authors: Duan, Jianhong, Wei, Kun, Du, Qianbiao, Ma, Linzhao, Qi, He, Li, Hao
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.12.2024
• Subjects: Ceramics; Electric fields; Energy storage; Entropy; Ferroelectricity; Figure of merit; Functional integration; lead‐free ceramic; Mechanical properties; Polarization; polarization configuration; Synergistic effect; Tungsten bronze
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202409446

In the field of dielectric energy storage, achieving the combination of high recoverable energy density (Wrec) and high storage efficiency (η) remains a major challenge. Here, a high‐entropy design in tungsten bronze ceramics is proposed with disordered polarization functional cells, which disrupts the long‐range ferroelectric order into diverse polar nanoregions (PNRs) characterized by composition fluctuation and cation displacement. These PNRs lower the domain‐switching barriers and weaken domain intercoupling, thereby playing a key role in delaying polarization saturation, reducing energy loss, and enhancing the breakdown electric field (Eb). Benefiting from the synergistic effects, at a large Eb of 760 kV cm−1, breakthrough energy storage performance is realized in tungsten bronze ceramics, including a record‐high Wrec of ≈10.6 J cm−3, an ultrahigh η of ≈96.2%, and a record‐high figure of merit of ≈279. These developments, along with superior mechanical properties, stability, and charge–discharge performance, fully demonstrate the feasibility of this strategy for realizing structural‐functional integration in tungsten bronze ceramics. The long‐range ferroelectric order is disrupted into diverse polarization configurations through a high‐entropy strategy, leading to a record‐high energy density of 10.6 J cm−3 in tungsten bronze and an ultrahigh efficiency of 96.2% at a high electric field. These results, combined with excellent mechanical properties and stability, indicate the successful design of structure‐function integrated ceramics.