High‐Energy Density Capacitors Utilizing 0.7 BaTiO ₃ –0.3 BiScO ₃ Ceramics

Abstract

A high, temperature‐stable dielectric constant (∼1000 from 0° to 300°C) coupled with a high electrical resistivity (∼10 12 Ω·cm at 250°C) make 0.7 BaTiO 3 –0.3 BiScO 3 ceramics an attractive candidate for high‐energy density capacitors operating at elevated temperatures. Single dielectric layer capacitors were prepared to confirm the feasibility of BaTiO 3 –BiScO 3 for this application. It was found that an energy density of about 6.1 J/cm 3 at a field of 73 kV/mm could be achieved at room temperature, which is superior to typical commercial X7R capacitors. Moreover, the high‐energy density values were retained to 300°C. This suggests that BaTiO 3 –BiScO 3 ceramics have some advantages compared with conventional capacitor materials for high‐temperature energy storage, and with further improvements in microstructure and composition, could provide realistic solutions for power electronic capacitors.