High-entropy engineered dipole glass in tungsten bronzes for high capacitive energy storage

Abstract

Tungsten bronze, the second largest ferroelectric family after perovskite, has been extensively studied in the field of dielectric energy storage. However, tungsten bronze ceramics, especially the filled type, face a severe challenge of reaching high energy density and high efficiency, making it difficult to match the energy storage performance of perovskites. In this work, we propose high-entropy strategy in filled type tungsten bronze ceramics to meticulously engineer dipole glass, manifesting as completely different polarization magnitudes and angles between adjacent dipoles. Combining the apparent enhancement of breakdown strength and the significant reduction of polarization hysteresis loss driven by highly disordered dipole glass, an impressive recoverable energy density of 8.9 J/cm³ with an ultrahigh efficiency of 91 % can be achieved in the high-entropy tetragonal filled tungsten bronze ceramics, endowing tungsten bronzes with considerable energy storage competitiveness compared to perovskites. This work provides an effective avenue to develop and expand new high-performance energy storage materials.