Nitrogen-enriched nonporous carbon electrodes with extraordinary supercapacitance

Abstract

Nitrogen-enriched nonporous carbon materials derived from melamine-mica composites are subjected to ammonia treatment to further increase the nitrogen content. For samples preoxidized prior to the ammonia treatment, the nitrogen content is doubled and is mainly incorporated in pyrrol-like groups. The materials are tested as electrodes for supercapacitors, and in acidic or basic electrolytes, the gravimetric capacitance of treated samples is three times higher than that of untreated samples. This represents a tenfoldincrease of the capacitance per surface area (3300 μFcm-2) in basic electrolyte. Due to the small volume of the carbon materials, high volumetriccapacitances are achieved in various electrolytic systems: 280 F cm-3 in KOH, 152 F cm-3 in H2SO4, and 92 F cm-3 in tetraethylammonium tetrafluoroborate/propylene carbonate.2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.