Lead-free BaTiO3-based ceramics modified by Bi(Mg0.5Sn0.5)O3 with enhanced energy-storage performance and charge–discharge properties

Fine-grained (1 − x)BaTiO3–xBi(Mg0.5Sn0.5)O3 (abbreviated as BT-xBMS, x = 0.04–0.16) lead-free ceramics with single perovskite structure were fabricated by a traditional solid-state reaction route. The microstructures, dielectric behaviors, energy-storage performance and charge–discharge properties have been investigated. The increasing addition of BMS results in a transition from tetragonal to pseudo-cubic phase, accompanied with a decrease in average grain size. It shows typical relaxor-like behaviors at x > 0.04, which can be characterized by strong frequency dispersion and diffuse phase transition. The BT-0.12BMS ceramics exhibit optimum energy-storage performance with a recoverable energy density of 1.31 J/cm3 at the electric field of 20 kV/mm. The excellent charge–discharge reliability over 105 cycles is also achieved at x = 0.12. The superior energy density and cycling stability indicate that the BT-0.12BMS ceramics have great potential for application in pulsed power systems. Meanwhile, this work interprets the mechanism of improved cycling stability in BaTiO3-based ceramics associated with domain configuration and defect structure.