Nanocomposite Enabled High Energy Density Capacitors for Pulsed Power Applications REVISED

High-energy-density capacitors are needed in a number of applications for high energy physics research, including solid state pulsed power systems. A capacitor¿s energy storage density can be increased by either increasing the dielectric constant or the electric field. Since the electric field is limited by the dielectric strength of materials, increases in the dielectric constant are sought. Although filled polymer-ceramic systems have been considered, the large volume fraction loading of particles adversely affects the mechanical properties and dielectric strength. Another suggestion has been to increase the dielectric constant in a "percolative dielectric nanocomposite," where a nanoparticulate conductive filler is added to the polymer matrix. However, the problem with this system is high dielectric loss due to the high conductivity of the fillers and a tendency of the fillers to form a conductive network. Therefore, a new and inexpensive dielectric material system, which has both high dielectric constant and low dielectric loss, is needed for future capacitors for solid state pulse power systems. This project will develop technology to overcome the conductivity problem with percolative dielectric nanocomposites, thereby realizing their full potential, and leading to high dielectric constant and low loss materials. Commercial Applications and other Benefits as described by the awardee: A reliable, high dielectric constant, low loss dielectric material should be beneficial to the next generation linear collider by: (1) raising the dielectric constant, thereby increasing the capacitor energy density beyond that of capacitors made of polymer films; (2) improving system reliability; and (3) reducing cost, since expensive materials (e.g. carbon nanotubes) will not be used. The capacitors also should benefit any industry where capacitors with high dielectric strength and low loss are needed. An example is the electronics industry, where miniaturization necessitates the replacement of discrete capacitors with embedded capacitors, which require materials with high dielectric constant.