To understand the mechanisms underlying the results displayed in Figure , we turn to the cation distributions in the multiparticle system displayed in Figure . We observe that for the high polarity case, the cation presence on the bulk sites is significantly enhanced compared to that for the low polarity case (SI, Section S5.6). This redistribution can be understood as a consequence of the stronger electrostatic interactions between the cations and the high polarity solvent molecules. As a result, we deduce that cation transport through the solvent dictates D cat values for the high polarity case. Since the cation mobilities through the solvent for the high polarity case (Figure ) are considerably higher than those along the surface for the low polarity case (Figure ), the conductivities are substantially increased by using a high polarity solvent.