In May 1996, Hyperion Catalysis International, Inc. began work under a Phase I SBIR contract aimed at affordable high performance electrochemical capacitors based on our proprietary carbon nanofibers. Phase I has already demonstrated that very high power density can be achieved. Further, the electrodes have excellent frequency response characteristics, also important for pulse power uses. Finally, the form of the electrodes, robust semi-rigid mats, appears to be of great interest to the capacitor community because it may reduce fabrication costs. The goal of Phase II is to demonstrate performance of a practical carbon nanofiber electrochemical capacitor, consistent with the Phase I results to date, i.e. power density on a cell basis of ca. 8.0 KW/Kg and energy density on a cell basis in excess of 2.5 KJ/Kg. Acceptable cycle life, leakage current and cost will also be demonstrated. By a practical capacitor, we mean one produced by a capacitor manufacturer from electrodes supplied by Hyperion. The electrodes, in turn, would be made from our commercially available nanofibers by a scaleable pilot line using chemical treatments, to alter the surface functional groups, and both chemical and physical methods to affect the texture of the electrodes.
