Physical properties and compatibility with graphite and lithium metal anodes of non-flammable deep eutectic solvent as a safe electrolyte for high temperature Li-ion batteries

In this study we present the original formulation of a deep eutectic mixture based on lithium imide salt as an electrolyte for Li-ion batteries. The non-flammable liquid obtained by mixing asymmetric (fluorosulfonyl) (trifluoromethanesulfonyl) (LiFTFSI) with ethylene carbonate (EC) demonstrates its applicability safer By comparison conventional electrolytes containing same salt, in 3EC/7EMC and EC/PC/3DMC, volumetric properties (EC-LiTFSI, 3/1, w), abbreviated EC-LiTFSI31, reveal strong nature FTFSI−—EC coordination non-solvation Li+, explaining "stacking" effect observed. Transport (viscosity, conductivity ionicity) are discussed compared to those electrolytes, demonstrating that EC-LiTFSI31 has typical ionicity organized media such ionic liquids or DESs, even if concentration is similar 1 mol L−1. electrochemical evaluation compatibility metal graphite Li//Li Gr//Li half-cells shows does not cause any erratic polarization over time it very good intercalation stability during charge/discharge graphite. thermal gives performance outstanding cell cycling at C/20 C/10 up 80 °C, 5 months (100 cycles) without damage battery. This could prove be promising battery safety, which remains main concern industrialists field.