In what follows, we assess which physical effects give rise to the changes in the PMFs observed from the bulk to nanoconfined electrolytes, examining the roles of (i) ion solvation and (ii) the lattice structure and electronic properties of the graphene. To quantify changes in solvation, we consider the number of water molecules coordinating each ion as a function of ion pair separation, shown in Fig. for the smallest and largest slits studied. In the H = 16.75 Å slit, the coordination number increases from the CIP regime to the CIP-to-SSIP barrier and then becomes relatively constant. In contrast, in the H = 6.70 Å slit, we see larger variations in coordination number which reflect the steric constraints on ion solvation imposed by confinement. We additionally observe that the chloride coordination number in the H = 6.70 Å slit is only slightly lower than in the larger slits, while the sodium coordination number decreases more significantly. The fact that chloride can preserve a relatively high coordination number while confined at the interface may contribute to its greater propensity over the sodium ion to adsorb to the carbon, as seen in the density profiles in Fig. .