An electrochemical evaluation of state-of-the-art non-flammable liquid electrolytes for high-voltage lithium-ion batteries

The rapid and accelerating adoption of lithium-ion batteries worldwide, especially in the transportation sector, has focused attention on their safety. One area particular interest is finding alternatives for most flammable component, liquid electrolyte. Over past 20 years, a number non-flammable electrolytes have been identified tested. However, because these data are frequently obtained under wide range conditions – e.g., different active materials, current densities or voltage cutoffs it difficult to compare them. In this work, eight promising four phosphate derivatives based fluorinated hydrocarbons from literature tested commercially relevant high-voltage systems identical conditions. electrochemical stabilities were studied against both inert electrodes LiNi0.6Mn0.2Co0.2O2|graphite cells. Each electrolyte was assessed via long-term cycling experiments rate-testing cell resistance during aging monitored. It found that containing phosphonate-based solvents generally performed very poorly compared phosphorus-free solvents; latter resulted, average, twice capacity retention after 500 cycles former. A strong correlation observed between performance, rate capability resistance.