Abstract
? 2022 Elsevier B.V.Defect engineering has attracted significant interest in perovskite oxides because it can be applied to optimize the content of intrinsic oxygen vacancies (VO) for improving their recoverable energy-storage density (Wrec). Herein, we design 0.84Bi0.5+xNa0.5-xTiO3-0.16KNbO3 (?0.02 ≤ x ≤ 0.08) relaxor ferroelectric ceramics with A-site defects and discuss the influence of VO on Wrec. The composition with x = 0.02 has a high Wrec (3.35 J/cm3) as well as a high efficiency (η = 91%) at 240 kV/cm, and exhibits excellent temperature, frequency, and fatigue stabilities. This optimized composition also provides a large discharge-energy-density (WD = 1.0 J/cm3), a high power-density (PD = 66 MW/cm3), a fast discharge-rate (122 ns) at 150 kV/cm, and favorable temperature-induced charge-discharge properties (CDPs). Electron paramagnetic resonance, X-ray photoelectron, and Raman spectroscopic results reveal that the outstanding comprehensive performance of the designed materials is attributed to the coupling effect of low contents of dimeric TiTi′?VO?× clusters and high contents of trimeric TiTi′?VO???TiTi′× clusters. This work provides key insights relevant for developing lead-free ceramics with excellent energy-storage properties (ESPs).
NSTL
Elsevier