Previous studies on blends of ionic liquids and organic carbonates paid particular emphasis on improved macroscopic properties such as safety performance and enhanced electro-chemical properties, while often neglecting the molecular details that govern the achievable ion transport properties of such blends, which are extensively considered in this work. Further studies on microstructures and interactions of ionic liquids at molecular level, as pure compounds or in the presence of dissolved species, is useful to design of suitable ionic liquids for a particular application, and this facilitates the selection of an optimum conditions of transport and thermodynamic properties. The ability to form mixtures of ILs with organic carbonates and other solvents has become increasingly important, and this is heavily influenced by the nature of those electrostatic interactions. Those properties are not accessible to experiments, yet important for boosting this innovative line of research by helping to and unravel all the fundamental microscopic features escaping experimental probes. The purpose of current work is, therefore, to unravel the microstructures and ion-ion interactions of ionic liquids at molecular level, both as pure components and in the presence of dissolved carbonate solvents and to critically compare the impact of adding carbonate (EC/DMC) co-solvents on the ion-ion interactions and the structural properties of the corresponding blends using 1M LiTFSI as conducting lithium salt.