Tailoring phase evolution via high-entropy engineering for superior energy storage properties in (Na0.5Bi0.5)0.75Sr0.25TiO3-based ceramics

Abstract

High-entropy engineering has garnered significant attention for innovation of dielectric capacitors. However, to meet the demands of the burgeoning market for next-generation advanced capacitors, challenges remain in optimizing the recoverable energy-storage density (Wrec). To address this, a stepwise high-entropy tactic is proposed via integrating four core effects of high-entropy systems with phase transition and energy-storage performance. This technique induces a remarkable Wrec ∼ 7.4 J/cm3 at 400 kV/cm in (Na0.5Bi0.5)0.75Sr0.25Ti1-x(Al1/4Zr1/4Hf1/4Nb1/4)xO3 ceramics (x = 0.00, 0.08, 0.12, 0.16, 0.20). The incorporation of multiple ions with diverse radii and valence states at the B-site enhances the degree of disorder and lattice distortion, contributing to tuning phase evolution and suppressing interfacial polarization, thereby delaying saturation polarization. Furthermore, impressive thermal endurance (30 ∼ 130 ℃), frequency stability (1 ∼ 100 Hz) and a rapid discharge rate t0.9 of ∼ 37.6 ns are also yielded. This work paves the way for the advancement of novel ceramics by tailoring phase transition using a high-entropy strategy.