Computational studies of carbon-onions for electrochemical capacitor applications

Supercapacitors bridge the gap between conventional batteries and electrolytic capacitors. Recently, onion-like carbon structures have [1] shown to have capacitances four orders of magnitude higher and energies an order of magnitude higher than conventional capacitors, making them the fastest growing competitors for energy storage. We study the formation of carbon-onions from nanodiamonds using reactive force-fields [2]. Our study suggests that the temperature and mechanical stability as well as the final-equilibrium structure are strongly dependent on the inclusion of long-range forces. We are currently developing reactive-force fields to allow mesoscopic modeling of reactions of carbon nanostructures with aqueous electrolytes. Progress along these lines will also be presented. This material is based upon work 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.\\[4pt] [1] D. Pech et. al, Nature Nanotechnology 5, 651 (2010)\\[0pt] [2] Adri C. T. van Duin et.al, J. Phys. Chem. A 105, 9396 (2001)