Abstract
Capacitive energy storage mechanisms in nanoporous carbon supercapacitors hinge on endohedral interactions in carbon materials with macro-, meso-, and micropores that have negative surface curvature. In this article, we show that because of the positive curvature found in zero-dimensional carbon onions or one-dimensional carbon nanotube arrays, exohedral interactions cause the normalized capacitance to increase with decreasing particle size or tube diameter, in sharp contrast to the behavior of nanoporous carbon materials. This finding is in good agreement with the trend of recent experimental data. Our analysis suggests that electrical energy storage can be improved by exploiting the highly curved surfaces of carbon nanotube arrays with diameters on the order of 1 nm.
Original language | English |
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Pages (from-to) | 1525-1531 |
Number of pages | 7 |
Journal | Journal of Materials Research |
Volume | 25 |
Issue number | 8 |
DOIs | |
State | Published - Aug 2010 |
Funding
We gratefully acknowledge the support from the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory (ORNL) and from the Center for Nanophase Materials Sciences, sponsored by the Division of Scientific User Facilities, U.S. Department of Energy. G. Yushin was supported by the Air Force Office of Scientific Research, Physics and Electronics Directorate. Y. Gogotsi was supported as part of the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award No. ERKCC61.