Overdischarge Induced Porous Graphite for Upcycling of Spent Lithium‐Ion Batteries

ABSTRACT

The upcycling of spent lithium‐ion batteries (LIBs) into high‐performance materials offers both economic and environmental benefits. In this study, the principle of battery discharge‐induced copper dissolution and deposition is applied to fabricate a graphite/nanocopper composite anode. Prolonged physical discharge of spent batteries can increase the copper content from the current collector in the anode active material. This process induces a gradient distribution of copper on the surface of the active anode material and within the solid electrolyte interphase (SEI). Upon recycling, the graphite active material undergoes thermal treatment to allow the CuO to react with graphite to form a porous surface for better lithium storage. This porous anode exhibits an initial charge capacity of nearly 372.6 mAh g ⁻¹ at 0.1C, a reversible capacity of 342.0 mAh g ⁻¹ after 300 cycles at 0.5C, and still maintains a reversible capacity of approximately 316.0 mAh g ⁻¹ at 1C. The presence of a porous surface and a thin SEI layer is beneficial for the fast charging capability and cycling stability of the recycled graphite. Economic and environmental analysis demonstrates that this upcycling method for spent graphite effectively reduces carbon emissions while improving economic benefits.