Enhancing the energy storage properties of BaTiO3 ceramics by coating with ternary transition metal oxide FeO-NiO-ZnO

The ternary transition metal oxide 40FeO-40NiO-20ZnO ((FNZ)O) was coated on the surface of BaTiO 3 (BT) powder to prepare (FNZ)O@ BT ceramics powder with uniform core-shell structure. The (FNZ)O coating effectively inhibits grain growth during the sintering process, reducing the grain size from 30 μm in pure BT ceramics to an ultra-fine grain size of 197 nm with uniform grain distribution. XRD analysis showed that the crystal structure of the ceramics gradually changed from tetragonal phase to cubic phase with the increase of the (FNZ)O. Under the electric field of 225 kV/cm, the highest discharge energy density (W d ) of 1 wt%(FNZ)O@ BT ceramic is 1.49 J/cm 3 , and the energy storage efficiency(η) is 71.3 %. The dielectric properties of (FNZ)O@ BT ceramics meet the X7R standard, it shows good temperature stability. In addition, 1 wt%(FNZ)O@BT ceramics also have very good high cycle stability (up to 10 5 cycles) and fast charge and discharge characteristics (τ 0.9 <0.75 μs). In this study, the core-shell structure prepared by coating ternary transition metal oxides opens up a way for the preparation of new functional materials.