Recycled Graphite for Sustainable Lithium-Ion Batteries

Abstract

Graphite – natural or synthetic – is the most dominant active material used for LIB anodes[1]. Natural graphite, however, is considered a critical material within the EU[2], while synthetic graphite is obtained from coke[3] – a carbon precursor produced from coal or petroleum. Therefore, efficient recycling and reuse of graphite are essential towards sustainability and resource preservation[4].Herein, we report a novel and highly efficient process to recover high-quality graphite from spent LIBs. Following a comprehensive physicochemical characterization of the materials obtained, we conducted an extensive electrochemical characterization in half-cells and graphite‖NMC532 full-cells and compared the results with the data obtained for half-cells and full-cells using pristine commercial graphite. In half-cells, the recycled graphite shows remarkably high reversible specific capacities (e.g., 350 mAh g- 1 at C/20) and very stable cycling for several hundred cycles at 1C. The graphite‖NMC532 full-cells also show excellent cycling stability, with a capacity retention of 80% after about 1,000 cycles. Particularly, the comparison with the pristine graphite comprising full-cells reveals very comparable performance, highlighting the great promise of recycled and reused graphite as a pivotal step towards truly sustainable LIBs and the great goal of a circular economy.