The local nano-structural organization and physicochemical properties of ILs arise as a direct consequence of the characteristics of the constituent ions and the intermolecular interactions present between the ions in individual systems . ILs are dominated by columbic and weak Where E(IP) is the energy of the ion pair, and E(cation) and E(anion) are the energy of the cation and anion, respectively. For the ion pair [EMI][TFSI], the absolute value of the interaction energies is lower than the normal hydrogen bond energies (50 KJ.mol -1 ), which indicates that there exist strong electrostatic attractions between the imidazolium cations and TFSI anions.