An electrolyte based on fluorinated carbonate solvents was evaluated with high voltage cathode materials at elevated temperature. The theoretically high anodic stability of these new electrolytes was supported by electrochemical evaluation results using LiNi_0.5Mn_1.5O₄/Li and LiNi_0.5Mn_1.5O₄/Li₄Ti₅O₁₂ electrochemical couples. Fluorinated carbonate appears to be a suitable electrolyte candidate for transition metal oxide cathodes at high voltage (5 V vs. Li⁺/Li).