3.3 Contribution of Ion Desolvation to Capacitance
Now we start to analyze the ion desolvation effect on capacitance. To validate the feasibility of CDFT in combination with the RPM coarse-grained model for predicting capacitance, comparisons between the CDFT calculation and relevant simulation59are performed and shown in Figure 6 . In the simulation, the electrochemical properties of hard-sphere ions near a planar hard wall are investigated, in which the relative dielectric constant is set as = 78.50 for mimicking aqueous solution, and a moderate electrolyte concentration is adopted as = 1.0 M with equal diameters of cation and anion = 0.40 nm. The system temperature is = 298.15 K. The identical system parameters are used in the CDFT calculation except that a nanoslit with pore width is applied. The comparison shows that our coarse-grained-model based CDFT calculation gives satisfactory predictions on the relation between surface voltage and surface charge density, and the relation between the capacitance and the surface charge density except a little overestimate at the peaks.