Solvation plays a key role in determining the capacitance behavior of the electrochemical interface, yet it presents significant challenges for computational modeling due to its complexity. We have recently demonstrated (doi: 10.1063/1.4976971) that the solvation models currently implemented in density functional theory (DFT) codes such as VASP perform poorly for the capacitance of aqueous metallic interfaces. In this talk, I identify solvation model characteristics that are necessary for capturing the nonlinear capacitance behavior of aqueous metallic interfaces.