A 300V Electromechanical Capacitor: Research and Development Thererof

40424 November 18, 1996 Covalent Associates, Inc. Over the last decade, extensive work has focused on increasing the energy and power density of electrochemical capacitors. Applications such as hybrid propulsion systems for electric vehicles have in large part driven this research. For electrochemical capacitors to meet the requirements for hybrid propulsion systems, energy and power densities greater than 5 Wh/kg and 0.4 kW/kg, respectively are needed. To exceed these requirements, this project will develop a packaged 4 volt per cell electrochemical capacitor. This capacitor will use a high conductivity non-aqueous electrolyte (>15 mS/cm) and activated carbon fiber electrodes. The thermal stability and operating temperature range of this electrolyte is greater than presently available (-40oC to >150oC). The electrolyte will be optimized for conductivity, and the capacitance will be investigated using novel activated carbon fibers. The system will be assembled in single cell pouches with an expected energy density approaching 15 Wh/kg. These pouches will be assembled into a multicell device. Anticipated Results/Potential Commercial Applications as described by awardee: Devices based on this work should provide a cost effective electrochemical capacitor for implementation into hybrid propulsion systems for electric vehicles.