Use the Functional Electrolyte Containing 2-Propynemethanesulfonate or 2-Propynebenzenesulfonate Additives to Improve the Long-Cycle Performance of LiNi_0.8Co_0.1Mn_0.1O₂/Graphite Batteries

By the aid of calculation and electrochemical methods, two functional electrolytes containing additives 2-proparylene methane sulfonate (2PMS) and 2-proparylene benzene sulfonate (2PBS) respectively are developed to improve the long-cycle performance of LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811)/graphite batteries. Compared with the batteries without the additives, the cycling lifetime of the batteries with 2PMS (or 2PBS) can be increased from about 900 cycles to more than 1200 cycles at room temperature and 1 C, and the rate capability, low temperature discharge and high temperature calendar performance are also enhanced. It is demonstrated that these two additives facilitate the formation of uniform electrode/electrolyte interfaces with low impedance and high stability to reduce the side effects of electrolyte, stabilize the active materials, and finally improve the battery performance. These results not only show the effectiveness of the electrolytes with 2PMS (or 2PBS) in the long-cycle NCM811/graphite batteries, but also have enlightenment for developing sulfonate-based additive functionalized electrolytes.