Carbon Aerogels Synthesized via Ambient Drying as Supercapacitor Electrode Materials with High Specific Capacitance
Organic gels (OGs) were formed by polymerization of resorcinol and formaldehyde with varying amounts of distilled water (0.883g in Gel1, 2.894g in Gel2 and 4.904g in Gel3 respectively) using (NH4)2CO3 catalyst. The organic gels formed after polymerization were dried at ambient conditions for two days followed by pyrolysis at 900oC in inert (N2) atmosphere. Nitrogen adsorption-desorption measurements indicate that all three CA samples dried at ambient conditions have high microporosity and exhibit Langmuir type of monolayer adsorption isotherms. However, SSA of the materials decreases with amount of water content. BET analysis, SEM and TEM data will be presented for understanding the differences implied by the relative amount of R-F to water content. Supercapacitor electrodes were made from slurry prepared by mixing CA materials in 1wt.% PVDF in NMP and deposited onto etched copper foil (from MTI®) using doctor-blade followed by drying in vacuum and hot pressing at 2500 PSI. The electrochemical properties of the cells assembled in symmetric CR 2325 coin cell supercapacitor geometry using Celgard® polypropylene (PP) membrane separator will be discussed in terms of cyclic voltammetry, galvanostatic charging-discharging, electrochemical impedance and durability tests. The structure dependent electrochemical properties such as specific capacitance, energy density, power density, and cycle stability in aqueous (6M KOH) and organic electrolyte (NEt4BF4/1M Acetonitrile) will also be discussed in comparison to graphene platelets from STEM Chemicals as a baseline.
 Horikawa T, Hayashi Ji, Muroyama K. Controllability of pore characteristics of resorcinol–formaldehyde carbon aerogel. Carbon. 2004;42:1625-33.