Enhanced energy-storage performance and dielectric temperature stability of (1-x)(0.65Bi0.5Na0.5TiO3-0.35Bi0.1Sr0.85TiO3)-xKNbO3 ceramics

Abstract Leed-free ferroelectric (1- x )(0.65Bi 0.5 Na 0.5 TiO 3 −0.35Bi 0.1 Sr 0.85 TiO 3 )- x KNbO 3 (BNBST- x KN) ceramics were prepared by the conventional solid state sintering method. The dielectric, ferroelectric and energy-storage properties were systematically investigated. Temperature dependent permittivity curves showed the relaxation properties of BNBST ceramics enhanced with the increase of KNbO 3 . BNBST-15KN exhibited a high permittivity of 3484 and low dielectric loss of 0.003 at 150 °C. Furthermore, Δ e / e 150 °C varied no more than 10% within the tmperature range of 30–297 °C, indicating an excellent dielectric temperature stability. The introduction of KNbO 3 gave rise to a large P m while P-E loops kept slim in shape. Therefore, the optimum energy-storage performance was realized in BNBST-15KN with an energy-storage density W rec of 1.32 J/cm 3 and energy-storage efficiency η of 82.5% at 95 kV/cm, accompanied with superior temperature stability and fatigue performance. The results demonstrated that BNBST- x KN system was a promising lead-free candidate for energy-storage applications.