Effect of fluorinated additives or co-solvent on performances of graphite//LiMn2O4 cells cycled at high potential

Herein, a comprehensive study of electrochemical performances the combined effect fluorinated additives; fluoroethylene carbonate (FEC); and tris(2,2,2-trifluoroethyl) phosphite (TTFP) or 2,2,2-trifluoroethyl methyl (TFEMC) as co-solvent, on Graphite//LiMn2O4 cells cycled at high potential is reported. On one side, each additive has specific function, FEC dedicated to negative electrode TTFP opposite one. The electrolyte mixture with (4% + 1% TTFP) shown best ability reduce fading LiMn2O4 electrode, especially rates. other by studying comparative thermal transport properties formulated electrolytes different proportions TFEMC, we demonstrate that difference in charge distribution EMC TFEMC molecules induced presence fluorine atoms, modifies solvation model Li+ cation, changes its behavior CEI interface impact strongly performances. Finally, EIS investigation LMO/electrolyte interfaces demonstrates despite spontaneous chemical reactivity cathode over time, conductive good quality formed, which positively cyclability. This shows against LMO surface phenomena, combination adequate additives solvent can be solution not only avoid oxidative LMO-cathode, but also prevent harmful consequences Li-metal graphite-anode controlling lithium-ion.