Many grid-tied applications would benefit greatly from rapidly responding, compact high-power capacitors to supplement large-scale battery, flywheel, and other distributed storage options. Currently available high-voltage electrostatic capacitors do not meet energy density or reliability needs at reasonable costs; supercapacitors struggle with the desired power densities and require additional infrastructure for integration, balancing, and temperature control. Traditional ceramic-based capacitors offer high-energy densities under low-voltage operation, but suffer from permittivity saturation (a decrease in incremental storage capabilities with increased electric fields) and low reliability under high-operating voltages. Because stored energy varies directly with permittivity and with the square of applied field, maintaining high permittivity out to high fields has a huge impact on stored charge. The project team will fabricate and study novel non-saturating, high-permittivity ceramic solid solutions using commercially scalable fabrication techniques; the project involves understanding the fundamentals of what gives these materials the ability to maintain high permittivity values at high electric fields (K>1000 @ >100 kV/cm), as well as development of advanced fabrication technologies for mitigating reliability-destroying defects which traditionally plague ceramic dielectrics.
Targeted Completion Date: 4/30/2012
Results will be published in a peer-reviewed journal.