LAUSR

A series of novel (1 − x)(0.94Na0.5Bi0.5TiO3–0.06BaTiO3)–xNa0.73Bi0.09NbO3 (BNT–BT–100xNBN) (x = 0–0.15) lead-free ceramics were fabricated by conventional solid state reaction method. The effects of NBN modification on the phase evolution, dielectric behavior, ferroelectric property and energy-storage performance were comprehensively investigated. All samples showed the pseudocubic structure and excessive dopants resulted in the secondary phase. The introduction of NBN resulted in deteriorative relaxor properties and maked two distinct dielectric anomalies smeared mutually. Therefore, the sample with x = 0.10 displayed a high permittivity (~ 1988) and low dielectric loss (< 0.02) in a broad temperature range of 25–337 °C. In addition, when x = 0.1, the optimal energy-storage density Wrec reached up to 1.56 J/cm3 with energy efficiency η = 92.5% at 120 kV/cm. The excellent thermal stability and fatigue resistance of sintered ceramics make it possible to be applied for practical dielectric capacitors.