Over the past several decades, various ILs, in combination with organic solvents, have been proposed and tested as components for LIB electrolytes. Such approaches could represent a good compromise between fast ion transport properties (low viscosity) and improved safety (low flammability) of the resulting electrolyte . The incorporation of proper organic compounds into ionic liquid electrolytes was found to enhance the cycling performance of LIBs Overall, the mixed ILs/organic solvent liquid electrolytes have the potential to be applied to LIBs with high output voltage at elevated temperatures, while at the same time satisfying the requirement of LIB safety. However, a compromise would exist between thermal stability and electrochemical performance at elevated temperatures. Thus, a great effort needs to be put on the adjustment of the proportion of ILs and organic solvent. To further advance the development of LIB electrolytes with improved electrochemical performance by decreasing the viscosity, it is important to understand, at a more detailed and molecular level, the underlying molecular and electronic interactions which influence the viscosity and transport properties of such hybrid ILs . The detailed molecular and electronic information is required for the explanation of the cause of the low viscosity of the We mainly concentrate the molecular interactions between [EMI] + cations and [FSI] -anions, and how this behavior is influenced by the EC/DMC content. We end this article with conclusions.