New fluorinated sulfones were synthesized and evaluated in high voltage lithium-ion batteries using a LiNi_0.5Mn_0.3Co_0.2O₂ (NMC532) cathode. Fluorinated sulfones with an α-trifluoromethyl group exhibit enhanced oxidation stability, reduced viscosity and superior separator wettability as compared to their non-fluorinated counterparts. Their improved performance in high voltage NMC532/graphite cells makes them promising high voltage electrolytes for next generation high voltage high energy lithium-ion batteries.