Enhanced energy-storage performances of Bi2O3–Li2O added (1−x)(Na0.5Bi0.5) TiO3–xBaTiO3 thick films

In this study, energy-storage properties of (1−x)(Na0.5Bi0.5)TiO3–xBaTiO3 (abbreviated as NBT–xBT, x=0, 0.06) lead-free thick films were investigated. The temperature-dependent stability of the energy-storage density and leakage current performance were studied to demonstrate the practicability of the NBT–xBT lead-free materials. It was found that the addition of BT enhanced the breakdown strength and the difference between maximum polarization (Pmax) and remnant polarization (Pr) at the same time, resulting in the improvements of energy-storage properties. The maximum recoverable energy density of 2.3 J/cm3 with an efficiency of 45% was achieved under 550 kV/cm by NBT–0.06BT, which also displayed good energy-storage stability in the temperature range from room temperature to 200 °C. Simultaneously, the leakage current density of NBT–0.06BT was about one-tenth that of the NBT–0BT due to the addition of BT. These properties indicate that, compared with pure NBT, NBT–0.06BT thick films might be a promising environmentally friendly lead-free material for energy-storage capacitor application.