Low temperature sintering lead-free dielectric xBiScO3-(1-x)BaTiO3 for energy storage applications

Fabrication of ceramic capacitors requires technological breakthroughs to address growing concerns regarding sustainability, cost, and increased power consumption in the manufacturing process. Low temperature sintered xBiScO3-(1-x)BaTiO3 (BS-BT) with x = 0.4 is found to possess excellent energy storage performance and temperature stability. The grain size decreases from 3.5 μm sintered at 1100°C to less than 0.5 μm sintered at 800°C, leading to much improved breakdown field and energy storage properties. Recoverable energy density of 4.7 J/cm3 with a high efficiency of 89% was obtained at an electric field of 390 kV/cm, showing an excellent temperature stability over temperature range of 25–200°C and fatigue endurance for more than 105 cycles. Of particular importance is that the ceramic tape cofired with silver electrode over temperature range of 800–850°C shows no reaction and diffusion of silver at the electrode/ceramic interface, while a recoverable energy density of 3.3 J/cm3 was achieved with satisfactory efficiency of 80% at an electric field of 340 kV/cm when sintered in reduced atmosphere, expanding the electrode selection to low-cost base metal, such as Cu and Ni. This work provides a good paradigm in ceramic capacitor fabrications that will help reduce overall cost and power consumption by utilizing low temperature sintered lead-free dielectrics with comparable or even superior energy storage properties over state-of-the-art dielectrics. (Figure presented.).