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 N2 atmosphere. The specific surface area (<600 m2/g) and the electrical conductivity (∼50 S/cm) of carbon aerogels varied in sensitivity with the pyrolysis condition, while their densities (0.6 g/cm3) and porosities (70%) were found to be almost constant. Post heat-treatment of carbon aerogels around 300◦C in air atmosphere was very effective for improving the electrochemical properties of electrodes. The carbon aerogel electrode pyrolyzed at 800◦C 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