Nevertheless, there remains longstanding concerns over the safety of LiPF 6 based lithium salts for LIB applications particularly at higher temperatures. LiPF 6 is unstable and moisture sensitive at higher temperatures (>60 ºC), which degrades to other decomposition products, and this eventually results in capacity fading and thermal runaway of the corresponding LIBs . For these reasons, therefore, there has been considerable research interest to replace the [PF 6 ] -anions with novel anions, that have better thermal stability and enhanced cycling performance. . Ionic liquids (ILs) based on bis(trifluoromethanesulfonyl)imide [TFSI] - and fluorosulfonyl(pentafluoroethanesulfonyl)imide [FSI] - are leading candidate anions for LIB electrolytes as they generally exhibit better thermal stability, relatively low viscosity and higher ionic conductivity . The [TFSI] -anion has been designated as a benchmark anion in ILs by IUPAC. As a result, the [TFSI] -anion has been the focus of several experimental and theoretical studies . There are several benefits of using the [TFSI] -anion containing ILs for LIB electrolytes. For example, lithium bis (trifluoromethanesulfonyl)imide salt (LiTFSI) has good thermal , chemical and electrochemical stability, which makes it a good candidate for LIBs. In addition, LiTFSI readily dissolves in various kinds of electrolytic solvents, which gives higher ionic conductivity at room temperature (e. g., ca. 10 -2 Scm -1 in EC/DMC). Nevertheless, LiTFSI is corrosive towards Al current collector, limiting its application as main conducting salt for LIBs . Another structural analogue of the [TFSI] -anion is the [FSI] -anion. The [FSI] -anion has been studied as a component of ILs . The [FSI] -anion containing ILs exhibit lower melting points, lower viscosities, and higher conductivities compared to [TFSI] -based ILs . For a given type of solvent, the LiFSI based electrolytes generally have higher ionic conductivities (~25 ºC) than LiPF 6 and LiTFSI based conducting salts . Therefore, the [FSI] -anion based conducting salts are worth of scientific researches as essential component of high performing LIBs . As such, LiFSI has been implemented as a co-salt to improve the performance of contemporary LIBs, particularly in electric vehicles (EV) field .