Electrochemical Compatibility of Graphite Anode from Spent Li-Ion Batteries: Recycled via a Greener and Sustainable Approach

The massive use of lithium-ion batteries (LIBs) has resulted in the generation of tons of e-waste, which are determining factors for the sustainable economic growth of society. In this work, an efficient method of graphite recovery from spent LIBs is developed by facile water leaching. Further, the recovered graphite is washed with a dimethyl carbonate-based organic solvent, followed by heating under inert conditions. This postpurification process eliminates residual carbon black and solid electrolyte interphase (SEI) formed due to electrolyte decomposition on the graphite surface and enhances the degree of graphitization. Electrochemical studies reveal a significant improvement in stable discharge capacity of 325 mAh g-1 for purified graphite compared to the water-washed graphite (310 mAh g-1) at 0.1C. Besides, it delivers a remarkable capacity of 275 mAh g-1, with 75% capacity retention over 1000 cycles because of the reappearance of dense optimized SEI on graphite surface that allows good lithium-ion passivation and intercalation into the graphite layers at the high current density of 2C rate. The practical feasibility is further tested through a full-cell study composed of an as-synthesized NCA-811 cathode and a purified graphite anode. This work entails a sustainable recycling strategy for comprehensively utilizing state-of-the-art graphite anode for high-performance LIBs.