High-Energy Density Capacitors Utilizing 0.7 BaTiO3-0.3 BiScO3 Ceramics

A high, temperature-stable dielectric constant (similar to 1000 from 0 degrees to 300 degrees C) coupled with a high electrical resistivity (similar to 10(12) center dot cm at 250 degrees C) make 0.7 BaTiO3-0.3 BiScO3 ceramics an attractive candidate for high-energy density capacitors operating at elevated temperatures. Single dielectric layer capacitors were prepared to confirm the feasibility of BaTiO3-BiScO3 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 degrees C. This suggests that BaTiO3-BiScO3 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.