EC molecules and is a consequence of using a high polarity molecule as the only solvent, while the lower height of the first peak in the PF6 -/Li + RDF reflects the well-dissolved structure of the salt. A further important property is the density distribution within the liquid phase along the slab direction. In the density distribution of the three species (EC, Li + and PF6 -in Figure (b)) we observe three well-pronounced peaks starting at the contact plane (z = 0) and decaying to a constant value corresponding to the bulk electrolyte density around a distance of z = 3 nm from the contact plane. The bulk density is estimated to a value of 1.38 g/cm 3 and is as expected slightly above the reference value 1.32 g/cm 3 of the pure solvent. The observed peaks reflect the ordered layers of the liquid phase and are qualitatively in line with the familiar structure of the solid-liquid interphase density distribution. The excess of Li + compared to PF6 -within z = 3 nm is explained by the negative surface charge of the carbon atoms and is reminiscent of the electric double layer (EDL) structure. The overlap seen in the Li + and PF6 -peaks might indicate formation of ionic pairs at the interface and is in qualitative agreement with observations in. The charge within z = 3 nm is calculated from the difference in area under the Li + and PF6 - distributions and corresponds to +1.9 e, thus effectively screening the surface charge -2 e within z = 3 nm. Assuming a surface charge σ = 3.1 µC cm 2 at the graphite is equivalent to an applied voltage of ϕ = zσ ϵ 0 ∼ 1V , the resulting capacitance from the charge accumulated in the electrolyte is roughly equivalent to σ ϕ ∼ 3.1 µF cm 2 , thus in agreement with the literature. Further we briefly comment on the dynamic properties of the Li + within the electrolyte phase. In order to verify the effect of the density alternations near the contact plane on the diffusivity we calculate the diffusion coefficients from Li + trajectories labeled with respect to the z-coordinate. To account for the drift of Li + along the slab direction due to the electrode we subtract the mean displacement from the MSD such that the shift is removed. From the mean squared displacement (MSD) vs time plotted in Figure The estimated slope corresponds to a diffusion constant of D = 5 × 10 -5 nm 2 ps (dashed lines in 4 (a)) and is in the correct order of magnitude of the reported diffusivity of carbonate electrolytes. In Figures ) we can see a drop of the diffusivity for small values of z, reflecting the effect of the free energy barriers at the solid surface. The drop of diffusivity can be traced to the density alternations due to the layering shown in Figure . While this effect is most pronounced for the z-MSD (a decrease by a factor of 2), the slight anisotropy of the xy-MSDs close to the electrode likely reflects the anisotropy of the edge plane of graphite.