Enhanced energy-storage performance and dielectric temperature stability of (1-x)(0.65Bi(0.5)Na(0.5)TiO(3)-0.35Bi(0.1)Sr(0.85)TiO(3))-xKNbO(3) ceramics

Leed-free ferroelectric (1-x)(0.65Bi(0.5)Na(0.5)TiO(3) - 0.35Bi(0.1)Sr(0.85)TiO(3))-xKNbO(3) (BNBST-xKN) 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 KNbO3. BNBST-15KN exhibited a high permittivity of 3484 and low dielectric loss of 0.003 at 150 degrees C. Furthermore, Delta epsilon/epsilon(150 degrees C) varied no more than 10% within the tmperature range of 30-297 degrees C, indicating an excellent dielectric temperature stability. The introduction of KNbO3 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 eta of 82.5% at 95 kV/cm, accompanied with superior temperature stability and fatigue performance. The results demonstrated that BNBST-xKN system was a promising lead-free candidate for energy-storage applications.