Maria Forsyth

Lithium-ion batteries (LIBs) are widely utilized for energy storage in various technologies. Conventional organic electrolytes used in LIBs face challenges, such as safety risks, limited cycling performance, and narrow electrochemical windows. In this study, several organic ionic liquid electrolytes are investigated. These electrolytes are composed of a mixture of EC/EMC/DEC (1:1:1 wt) as the organic solvent, combined with various phosphonium-based ionic liquids (ILs) possessing different alkyl chains on the phosphonium cation, namely, trimethyl(isobutyl) phosphonium bis(fluorosulfonyl)imide (P111i4FSI), tri-n-butyl(methyl) phosphonium bis(fluorosulfonyl)imide (P1444FSI), and tri-n-butyl(decyl) phosphonium bis(fluorosulfonyl)imide (P44410FSI), serving as additives. Subsequently, the physicochemical properties and electrochemical behavior of all electrolytes are investigated. The results indicate that the compositions of EC/EMC/DEC 90% + P111i4FSI 10% and EC/EMC/DEC 50% + P111i4FSI 50% (wt %) have higher ion