Preparation of nitrogen-enriched carbon materials and their application for electrochemical capacitors

Novel nitrogen-enriched carbon materials prepared from heterocyclic hydrocarbons containing nitrogen atoms by an ordinary heat treatment method are reviewed. On account of the nitrogen atoms in the starting hydrocarbons, a certain amount (5–45 wt.%) of nitrogen remained in the resulting carbons. In addition, thin film, layered, mesoporous and fibrous structures were successfully introduced into the nitrogen-enriched carbon body using selective precursors and the template method. The obtained carbons exhibited a unique electrochemical capacitor performance such as high specific capacitance and do not appear to follow the normal relationship between electrolyte ions and pore structure on an electrode surface. These features can be attributed to the electrochemical interaction of nitrogen in the carbon network with electrolyte ions. Although some inexplicable anomalies remain, these nitrogen-enriched carbon materials have high promise as an electrochemical capacitor electrode material.