Enhanced energy-storage properties of (1-x)(0.7Bi0.5Na0.5TiO3-0.3Bi0.2Sr0.7TiO3)-xNaNbO3 lead-free ceramics

Abstract A series of (1- x )(0.7Bi 0.5 Na 0.5 TiO 3 -0.3Bi 0.2 Sr 0.7 TiO 3 )- x NaNbO 3 (BNT-BST-100 x NN) lead-free ceramics were fabricated using conventional solid-state reaction technique. The phase behavior, microstructure, dielectric, ac impedance and energy-storage properties of the sintered ceramics were systematically investigated. XRD patterns and surface SEM micrographs revealed the introduction of NaNbO 3 didn't change the perovskite structure of BNT-BST at low doping level. The NaNbO 3 doping gave rise to slimmer P - E loops and thus gained enhanced energy storage properties. Therefore, a maximum energy storage density of 1.03 J/cm 3 was achieved at 85 kV/cm at x = 0.01 via increasing the dielectric breakdown strength (DBS). Temperature-dependent dielectric permittivity illustrated the enhanced relaxor characteristics, implying the long-rang ferroelectric order was further damaged due to the introduction of NaNbO 3 . The results above indicate the sintered ternary ceramics can be a promising lead-free candidate for energy storage capacitors.