In ILs, the Li + solvation shell and conductivity are closely related. Li + ions with larger solvation shells have been reported to have lower ionic conductivity . A detailed investigation of the solvation of Li + ions is, therefore, helpful to the rational design of novel electrolytes with improved Li + ion conductivity. In the mixed IL/carbonate systems containing different mixed ratios of [EMI][TFSI] and EC/DMC, the role of each ingredient with regards to the solvation structure is not fully understood . In this section, we aim to elucidate the structural features of [EMI][TFSI] and EC/DMC mixed electrolyte systems and the influence of adding EC/DMC on the overall liquid structure. To fulfill our objective, we calculated center-of-mass and atomic pair radial distribution functions (RDF) and coordination numbers (CN). We analyzed the structures of the ILs and the changes they undergo upon the addition of EC/DMC co-solvents. The composition of each electrolytic system investigated in this study is shown in Table . The local structure was analyzed in terms of the most representative atom-atom pair RDF and CN in order to analyze and provide an insightful average picture of the IL/carbonate structure. The RDF for atom-atom pair and center of mass of the ions in this work was investigated according to the following relation (Equation ) :