Carbon Aerogels as Electrode Material in Supercapacitors
Tóm tắt
Due to their large specific surface area and their high electrical conductivity carbon aerogels are promising materials for electrodes in electrochemical double-layer capacitors (“supercapacitor”). The carbon aerogels were made via pyrolysis of resorcinol formaldehyde aerogels. The latter were prepared by supercritical and subcritical drying as well. The important findings of our investigation were, that the highest capacities of 46 F/cm3 were measured for samples with a density of about 800 kg/m3 pyrolyzed at 800°C. Also it was shown that RF-gels with molar resorcinol/catalyst ratios ≥1000 or higher can be dried subcritically without cracking or significant shrinkage. Carbon aerogels derived from these RF-aerogels have a small mesopore surface area, however an especially large micropore area. They provide electrical capacities which are most suitable for their use in supercapacitors.
Tài liệu tham khảo
S. Sarangapani, P. Lessner, J. Forchione, A. Griffith, and A.B. Laconti, J. of Power Sources 29, 355–364 (1990).
J.C. Currie, D.L. Boos, V.F. Gaylor, and P.D. Bennett, Proc. Symp. on the Chemistry and Physics Composite Media (Electrochem. Society, Pennington, NJ, 1985).
K. Sanada and M. Hosokawa, NEC Research and Development No. 55 (1979).
S.T. Mayer, R.W. Pekala, and J.L. Kaschmitter, J. of the Electrochemical Society 140(2), 446 (1993).
X. Lu, O. Nilsson, J. Fricke, and R.W. Pekala, J. of Applied Physics 73(2), (1993).
R.W. Pekala and C.T. Alviso, Novel Forms of Carbon, edited by C.L. Renschler, J.J. Pouch, and D.M. Cox, in Mater. Res. Soc. Symp. Proc. (1992), Vol. 270, p. 3.
F. Krüger, Measurements and Report, University Duisburg.
H. Shi, Electrochemical Acta. 41, 1633 (1996).
R.W. Pekala, S.T. Mayer, J.L. Kaschmitter, and F.M. Kong, Proc. of International Symposium on Advances in Sol-Gel Processing and Applications (Chicago, IL, 1993).