Structure, dielectric and relaxor properties of Sr0.7Bi0.2TiO3-K0.5Bi0.5TiO3 lead-free ceramics for energy storage applications

Sr0.7Bi0.2TiO3 (SBT) by increasing the proportion and size of polar nano-region. Meanwhile, the BDS remains a high level with x <= 0.38 attributed to the addition of KBT with a large band gap. As a result, the 0.62SBT-0.38KBT exhibits a high energy storage density of 2.21 J/cm(3) with high eta of 91.4% at 220 kV/cm and superior temperature stability (-55 similar to 150 degrees C), frequency stability (10 similar to 500 Hz) and fatigue resistance (10(5) cycles). Moreover, high pulsed discharge energy density (1.81 J/cm(3)), high power density (49.5 MW/cm(3)) and great thermal stability (20-160 degrees C) are achieved in 0.62SBT-0.38KBT. Based on these excellent properties, the 0.62SBT-0.38KBT are suitable for pulsed power systems. This work provides a novel strategy and systematic study for improving energy storage properties of SBT. (C) 2020 The Chinese Ceramic Society. Production and hosting by Elsevier B.V.