*** ABSTRACT 9661179 Johnson This Small Business Innovation Research Phase I project will explore the feasibility of using microtextured metal electrodes as the basis of electrolytic ultracapacitors. For load leveling and sustained function after many cycles, ultracapacitors promise to become an integral part of many advanced power systems, particularly for hybrid electric vehicles and remotely operated battery systems. Although lower in specific energy than batteries, ultracapacitors potentially have a high specific power, enabling a synergy with lower power, but higher energy capacity, batteries, flywheels, or fuel cells. Present ultracapacitor designs use a highly porous structure of carbon (activated, foamed, or aerogel) as a high surface area electrode. High capacitance is achieved by the double-layer of polar molecules extracted from the electrolyte, which follows the convoluted surface of the carbon-coated electrodes. We propose ultracapacitors based on microtextured metal electrodes made by ion beam sputtering. Microtextured metals should improve performance through increased conductivity and wettability, while maintaining large surface area and ease of manufacture. Such surfaces have previously demonstrated remarkable changes in secondary electron emission, battery electrode performance, and optical properties, all related to increased surface area. Similar enhancements of ultracapacitor electrodes promise to enable them to finally approach their theoretical performance limits. Ultracapacitors are, in combination with relatively lower power but high energy sources, ideal components of hybrid power supplies. In typical applications of current ultracapacitor technology to electrical vehicles, analysis by the National Renewable Energy Laboratory predicts a reduction in peak battery power demanded by a factor of three or more, an increase in vehicle range of 50%, and a doubling of cycle life. Similar, or even greater, benefits to communication devices, computers, and motor-driv en systems could be expected from microtextured metal electrodes. ***
