Superior Energy-Storage Properties in Bi<sub>0.5</sub>Na<sub>0.5</sub>TiO<sub>3</sub>-Based Lead-Free Ceramics via Simultaneously Manipulating Multiscale Structure and Field-Induced Structure Transition
Yi Zhang, Aiwen Xie, Jian Fu, Xuewen Jiang, Tianyu Li, Cong Zhou, Ruzhong Zuo
Abstract
Pratical applications have put forward great challenges to the comprehensive energy-storage performance of ceramic material. Here, a novel route of simultaneously manipulating multiscale structure and the field-induced structural transformation in (Bi0.5Na0.5)TiO3-based ceramics is proposed to address the above concern. The multiscale structure of 0.88(Bi0.5Na0.5)TiO3-0.12BaTiO3 solid solutions such as grain and domain size, band gap, and phase structure can be adjusted by adding antiferroelectric NaNbO3. Simultaneously, a field-induced P4bm relaxor antiferroelectric to P4mm ferroelectric phase transformation can be obtained by constructing a P4mm–P4bm phase boundary, which is expected to require a lower energy barrier compared with the field-induced P4bm relaxor antiferroelectric to R3c ferroelectric transformation in other (Bi0.5Na0.5)TiO3-based ceramics. The optimized field-induced structural transformation behavior and the formation of nanodomains enables a minimized polarization hysteresis but an enhanced maximum polarization. Moreover, the decreased grain size together with increased band gap leads to a significantly improved breakdown strength. Accordingly, a giant energy density Wrec ∼ 8.0 J/cm3, a high efficiency η ∼ 86%, a short discharging time t0.9 ∼ 41 ns, and a good temperature stability (Wrec = 1.32 ± 0.12 J/cm3, η = 88.5% ± 2.5% @ 25–200 °C) are simultaneously obtained in 0.63(Bi0.5Na0.5)TiO3-0.12BaTiO3-0.25NaNbO3 relaxor antiferroelectric ceramics, demonstrating large potentials for the ceramic capacitor applications.