  We report on the development of an original mesoscopic lattice model to
predict structural, dynamical and capacitive properties of carbon-carbon
supercapacitors. The model uses input from molecular simulations, such as free
energy profiles to describe the ion adsorption, and experiments, such as energy
barriers for transitions between lattice sites. The model developed is
approximately 10,000 times faster than common molecular simulations. We apply
this model to a set of carbon structures with well-defined pore sizes and
investigate the solvation effect by doing simulations with neat ionic liquids
as well as acetonitrile-based electrolytes. We show that our model is able to
predict quantities of adsorbed ions and capacitances in a range compatible with
experimental values. We show that there is a strong dependency of the
calculated properties on the pore size and on the presence or absence of
solvent. In particular, for neat ionic liquids, larger capacitances are
obtained for smaller pores, while the opposite trend is observed for organic
electrolytes.
