[TFSI] -anions are highly viscous and cause corrosion to the aluminium cathode current collector . It has been found that ILs involving bis(fluorosulfonyl) imide (FSI -), an anion which is the close structural analogue to that of the [TFSI] -, shows a significantly lower viscosity than [TFSI] -analogues (e.g., [FSI] =18 mPas; [TFSI] = 33 mPas) . Furthermore, [FSI] -has less problems of aluminium corrosion . By comparison, ionic liquids based on the [FSI] -anion show reversible Li + intercalation/extraction at graphite electrodes, whereas [TFSI] -containing ionic liquids do not form stable solid electrolyte interface (SEI) layer and thus, do not allow reversible Li + intercalation/extraction on the graphite electrode. Clearly, it is important to balance the prospects of developing hybrid electrolytes with enhanced electrochemical properties against any concerns of stability of these compounds. With this in mind, the purpose of the current study is to present detailed structural and electronic insights of imidazolium bis(trifluorosulfonyl)imide [TFSI]/bis(fluorosulfonyl)imide [FSI] hybrid electrolytic systems, and their mixtures with ethylene carbonate (EC)/dimethyl carbonate (DMC), which are potential candidates for next generation LIB electrolytes. We report on the ab initio (DFT) based molecular interactions of the individual ions, ion pairs and discuss the influence of adding carbonate co-solvents on their liquid structure, and explore details of ion-ion and ionsolvent interactions.