Fluorinated co-solvent electrolytes for high-voltage Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) positive electrodes

Nickel-rich LiNi 0.8 Co 0.1 Mn O 2 (NCM811) is one of the most promising positive electrodes for utilization in next-generation lithium-ion batteries. Charging NCM cells above 4.3 V proposed to be beneficial its reversible capacity. However, high reactivity NCM811 usually results parasitic electrolyte degradation, which accelerated with increase Ni content electrodes, leading thickening electrode-electrolyte interphase during cycling. Herein, counter this issue, we select partially fluorinated solvents, such as methyl 3,3,3-trifluoropropanoate (MTFP) and 1,1,1,2,2,3,3,4,4-nonafluoro-4-methoxybutane (NFMB), a co-solvent fluoroethylene carbonate (FEC)-based electrolytes, detailed investigate theirs physical, chemical, electrochemical properties applications materials. Compared carbonate-based without solvent, electrolytes display an obviously enhanced cycling performance Li/NCM811 charged 4.5 V. This work suggests that provide alternative way high-concentration design new systems energy density