To ensure the inclusion of sufficient water molecules for modeling contact and solventseparated ion pair structures, we conduct a preliminary molecular dynamics analysis. This involves increasing the number of water molecules surrounding a single NaOTF ion pair within a large simulation box (45 × 45 × 45 Å + ) and examining ion-ion and water-ion configurations to achieve the desired contact or solvent-separated arrangements. For this purpose, we employ the OPLS force field for ions and the SPC/E model 71 for water. Based on this analysis, we develop contact and solvent-separated ion pair models comprising 12 and 24 water molecules, respectively, which are then used in our DFT calculations. While our consistent use of DFT modeling for various adsorption scenarios in the presence of water allows for comparisons of energetic favorability among the resulting adsorption structures, it is important to acknowledge the limitations of our DFT model. Firstly, this model does not fully capture the complexities of ion desolvation during the adsorption process, as it neglects temperature effects, dynamic processes, and certain aspects of mutual interactions between the solvated ions and their neighboring electrolyte components. Secondly, the adsorption energies are determined with respect to ion pairs and their surrounding water molecules in the gas phase, which may introduce potential errors when applied to the liquid electrolyte environment. Therefore, subsequent ab initio molecular dynamics simulations are necessary for a more precise analysis of the SEI formation in the presence of solvation shells.