STTR Phase I: High Energy Density Non-aqueous Pseudocapacitors

The broader impact/commercial potential of this Small Business Technology Transfer Research Phase I project is development of novel organic materials necessary to produce high energy density, low cost pseudocapacitors. The active material will be a single substance for both oxidation and reduction. This important property reduces cost and fabrication complexity. The synthetic route to the active material is short, and makes use of commodity reagents. Pseudocapacitors capable of delivering more than 10 Watt hours per kilogram at 5,000 Watts per kilogram will have significant impact on vehicle performance, especially for the heavy vehicles that operate at high power levels getting started, for intermittent renewable sources, and uninterruptible power supplies. The low cost and high performance in these new pseudocapacitors will have important commercial impact in the US manufacturing arena because their fabrication is readily adapted to the existing infrastructure designed for other organic electrical devices. This project is based on organic compounds with unprecedented voltage and redox stability. Because this active material can be both oxidized and reduced as a single substance, it has the unique advantage of not needing an asymmetric design. Asymmetric or hybrid design is used in capacitors to increase the voltage window when the redox activity is otherwise confined to a relatively narrow band within the voltage window of the solvent and electrolyte. This system has a large voltage separation between the oxidation and reduction half reactions without the need for balancing mass, and without fabrication of two different electrodes. The single substance advantage combines the best properties of the asymmetric design within a symmetric cell. The research group has prepared materials with high cycle stability and open circuit potentials of 2.8 volts. Our goal will be to demonstrate that the use of our novel organic electroactive materials can significantly increase capacitance of high surface area double layer capacitors.