Electrochemical capacitors utilizing low surface area carbon fiber

The performance of electrochemical capacitors containing different commercial carbon fibers is reviewed. High specific capacitance (ca. 300 F/g) is obtained with low surface area carbon fiber (<1 m/sup 2//g) using a proprietary activation process. Capacitance is primarily achieved through pseudocapacitance resulting from surface functional groups. The performance of these devices is dependent on the type of carbon fiber, its carbon content, aspect ratio and microstructure. These devices can achieve high cycle life (ca. 100 k) without significant loss in capacitance.