Abstract by Nick Allen
Physics and Astronomy
Robert Davis, Richard Vanfleet
Hybrid Aluminum Electrolytic Capacitors for Advanced Energy Storage
While batteries have high energy-densities, capacitors can have higher power-densities which is valuable in many applications including hybrid cars, for example, that require a lot of energy at once. In capacitors, high energy and power densities require very high surface areas. They also need a dielectric with high permittivity and high breakdown-field strength. In this project I am using carbon nanotubes, with small diameters (~10nm) to produce ultra-high surface area conductive materials as an electrode and coating them with aluminum oxide, an excellent capacitor dielectric. Carbon nanotube forests were grown from a catalyst pattern on a silicon wafer using chemical vapor deposition in a furnace at 750 C. The nanotube forests were conformably coated with alumina using atomic layer deposition and the resulting structures were characterized using scanning electron microscopy. The other electrode is an electrolyte solution of potassium chloride, thus forming a hybrid aluminum electrolytic capacitor.