Energy storage performance of lead-free Ba0.7Sr0.3TiO3 ceramics with doping Bi(Mg0.5Ti0.5)O3

Despite extensive research into lead-free ceramics to achieve excellent dielectric properties and good energy storage performance, the primary challenge of low energy density remains unresolved. Here, a relaxor ferro-electric (1-x)Ba0.7Sr0.3TiO3-xBi(Mg0.5Ti0.5)O3 [(1-x)BST-xBMT] was designed and prepared using a solid-state method, where x = 0.05, 0.15, 0.20, 0.25. It revealed that the introduction of BMT reduces the average grain size, resulting in a decrease and broadening of the dielectric constant peaks. This modification enhanced the breakdown field strength (Eb) of BST ceramics. An effective energy storage density of 2.44 J/cm3 and an energy storage efficiency of 76.25 % ware achieved in 0.80BST-0.20BMT ceramic at an electric field of 300 kV/cm. Furthermore, the recoverable energy density and energy efficiency of the 0.80BST-0.20BMT ceramic exhibited excellent frequency stability over a frequency from 5 Hz to 500 Hz. A power density (PD-16.06 MW/cm3) and a short discharge time (t0.9-0.95 mu s) were demonstrated in 0.80BST-0.20BMT ceramic at 200 kV/cm.