ILs generally have some desirable features as electrolyte components for LIB. However, ILs also have undesirable features such as low wettability of the electrode surface and higher viscosity. The physicochemical properties of ILs can be enhanced by modifying ILs into hybrid electrolytes, either with lithium salts and/or organic solvents, which can effectively reduce the viscosity and ionic transferring resistance, and this thereby improves the ion transport and interfacial properties . One approach is to add a lithium salt with a different anion than in the original IL . For example, replacing [TFSI] -by [FSI] -, or combining the two, has been motivated by enhanced ionic conductivities and improved passivation of the aluminium current collector . Several IL based electrolytes with an imidazolium cation ([EMI] + ) have been investigated trying to find beneficial effect of mixing [FSI] -with [TFSI] -anions. A synergetic effect of having mixed anions was possible with the LiTFSI/[EMI][FSI] electrolyte giving the best overall performance . Another popular strategy is to mix ILs with organic solvents to form hybrid electrolytes with improved performance by decreasing the viscosity. Generally, the addition of ILs into organic solvent electrolytes was seen as a viable option to improve the electrochemical stability, which in most cases, is higher than organic solvent based electrolytes. For example, mixing of 70 wt% of 1-butyl-1-methylpyrrolidinium hexafluorophosphate ([Py 14 ][PF 6 ]) IL with conventional standard electrolytes based on 1M LiPF 6 /EC/DMC electrolyte solutions was found to improve the flash point of the electrolyte from 22˚C to 51˚C, while at the same time maintaining the ionic conductivity (10 -3 Scm -1 at 25ºC) . Over the past several decades, various ILs, in combination with organic solvents, have been proposed and investigated as electrolyte components for LIBs. 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.