Improve the compatibility of sulfolane-graphite with the synergetic additives

The high voltage stability (> 5.5 V) makes sulfolane (SL) an excellent electrolyte solvent candidate for high specific energy lithium-ion batteries. However, the stable solid electrolyte interphase (SEI) cannot be generated on the surface of graphite particles with SL , limiting its application. To solve the interface incompatibility, we introduce fluoroethylene carbonate (FEC) and lithium nitrate (LiNO 3 ) in SL-based electrolyte for constructing an inorganic-rich SEI on graphite. The comprehensive characterizations and simulations demonstrate that combined effect of additives facilitates the formation of additive-derived LiF-Li 3 N enhanced inorganic-rich SEI. The proposed electrolyte shows stable cycling performances with 324.89 mAh/g and 97.93 % after 50 cycles in Li/graphite half-cells, compared with the capacity of 24.54 mAh/g and the capacity retention of 19.4 % in SL-without additives. Importantly, the electrolyte system obtains a capacity retention of 71 % and the capacity of (127.93 mAh/g) is higher than that without additives (110.21 mAh/g) at 4.4 V after 200 cycles. This work solves the incompatibility of SL-graphite with low-cost additives, and is beneficial to realize the commercial application of sulfolane in high specific energy batteries.