Enhanced energy storage density of 0.55Bi0.5Na0.5TiO3-0.45Ba0.85Ca0.15Ti0.85Zr0.1Sn0.05O3 with MgO addition

0.55Bi0.5Na0.5TiO3-0.45Ba0.85Ca0.15Ti0.85Zr0.1Sn0.05O3-xwt%MgO ceramics were prepared by solid state route and their phase compositions and dielectric properties were investigated with the focus on improving energy storage density for capacitor applications. The XRD data results reveal that all samples possess a pure perovskite phase and some secondary phases of MgO and Mg2TiO4 can be observed in the MgO doped samples. The frequency dispersion gradually disappears by the addition of MgO and MgO doped samples show a diffuse phase transition behavior. Dielectric breakdown strength of the samples are greatly improved with the increasing content of MgO. The sample with x = 5 shows a high dielectric breakdown strength of 18.97 kV/mm, a high discharge energy density of 1.62 J/cm3 and a high energy efficiency of 79.51%, making it most suitable for application as high energy storage density capacitors.