Enhanced energy storage performance of Ba 0.4 Sr 0.6 TiO 3 ceramics: Influence of sintering atmosphere

Ba0.4Sr0.6TiO3 (BST) powders were prepared by hydrothermal method, the ceramics were sintered in N2, air and O2 atmosphere respectively. The effect of sintering atmosphere on the microstructure, dielectric properties, and energy storage performance of BST ceramics were investigated. The grain size of the BST ceramics sintered in O2 atmosphere was reduced to 0.44 µm, indicating the grain growth was significantly inhibited with increasing oxygen partial pressure due to the lack of oxygen vacancy. Dielectric relaxation behavior was observed in the BST ceramics, and the degree of which was increased with increasing oxygen partial pressure. BST ceramics sintered in O2 atmosphere showed the largest critical breakdown strength of 16.72 kV/mm, at which the highest energy storage density of 1.081 J/cm3 and a moderate energy storage efficiency of (73.78%) were obtained. The dependence of energy-storage properties on applied field was also investigated, it was found that the energy storage density increased with increasing applied filed while the energy storage efficiency decreased with increasing applied filed.