Preparation of carbon aerogel electrodes for supercapacitor and their electrochemical characteristics

A new process is presented for synthesizing the supercapacitor electrodes of carbon aerogel via pyrolyzing resorcinol-formaldehyde (RF) aerogel, which could be cost-effectively obtained by ambient drying of wet RF-gels instead of conventional supercritical drying. Defect free RF-aerogels instead of conventional supercritical drying. Defect free RF-aerogels with the linear shrinkage of less than 8% could be manufactured by ambient-drying of wet RF-gels. Carbon aerogels with high strength were prepared via pyrolyzing RF-aerogels in N-2 atmosphere. The specific surface area (<600 m(2)/g) and the electrical conductivity (similar to50 S/cm) of carbon aerogels varied in sensitivity with the pyrolysis condition, while their densities (0.6 g/cm(3)) and porosities (70%) were found to be almost constant. Post heat-treatment of carbon aerogels around 300degreesC in air atmosphere was very effective for improving the electrochemical properties of electrodes. The carbon aerogel electrode pyrolyzed at 800degreesC showed the specific capacitances of about 40 F/g in H2SO4 electrolyte solution and 35 F/g in KOH solution. (C) 2005 Springer Science + Business Media, Inc.