The regeneration of graphite anode from spent lithium-ion batteries by washing with a nitric acid/ethanol solution

Graphite is one of the main components of lithium-ion batteries (LIBs) because of its good recycling performance and uniform layers suitable for lithium intercalation. This study focused on the separation of spent LIBs, the isolation of the anode and the washing of its surface to remove the solid electrolyte interphase that leads to an increase in the electrical resistance. The spent graphite was incubated in a nitric acid/ethanol solution which cleans the spent graphite anode while retaining its original morphology. The regenerated graphite anode has a better electrochemical performance when used in a new lithium-ion battery than does the spent graphite, with no capacity loss at a current density of 50 mA·g⁻¹ for 60 cycles. A full battery using regenerated graphite as the anode and lithium iron phosphate as the cathode has a capacity retention of 92% at 0.5 C after 100 cycles. Our work provides a new strategy for regeneration of the anode graphite.