Enhanced energy-storage performance and thermally stable permittivity for K0.5Na0.5NbO3 modified [(Na0.5Bi0.5)0.84Sr0.16]0.98La0.01TiO3 lead-free perovskite ceramics.

(1- x)[(Na 0.5 Bi 0.5) 0.84 Sr 0.16 ] 0.98 La 0.01 TiO 3 - x K 0.5 Na 0.5 NbO 3 (abbreviated as NBSLT-100 x KNN) lead-free perovskite relaxor ferroelectric ceramics are synthesized through the conventional solid-state reaction. The effects of KNN on the ceramic polycrystalline structure, dielectric temperature stability, and energy-storage characteristics are studied systematically. All samples exhibit a single perovskite structure and compact surface morphology. Thermally stable dielectric permittivity (ε ′) is obtained from 62 to 331 °C range for NBSLT-5KNN ceramic with ε ′ ~ 2286 at 150 °C less than ± 10% fluctuation rate. The addition of KNN refines the hysteresis loops and gradually increases the dielectric breakdown strength, which endows NBSLT-5KNN ceramic with the best energy-storage performance compared to other compositions. A high effective energy-storage density (W rec) ~ 1.234 J/cm3 with efficiency (η) ~ 74.7% are acquired at 90 kV/cm. The energy-storage performance is revealed an excellent fatigue resistant stability. Hence, the introduction of KNN makes NBSLT-5KNN ceramic an outstanding competitor for energy-storage equipment applications. [ABSTRACT FROM AUTHOR]