A green and low-cost approach to recover graphite for high-performance aluminum ion battery cathode

The recovery of spent graphite (SG) from lithium-ion batteries (LIBs) has been neglected due to its relatively low value and the lack of effective recovery methods. In this study, a green and cost-effective water washing process was used to recycle the spent graphite of LIBs anode, and the recovered graphite (RG) was used as the cathode material of aluminum ion batteries (AIBs). The RG retained the integrated graphite structure after the water washing process, showing a slightly enlarged interlayer spacing. When used as a cathode material for AIBs, it exhibits better electrochemical performance than commercial artificial graphite. At a current density of 50 mA g⁻¹, the RG shows a high specific capacity of 95.2 mAh g⁻¹. At a high current density of 2000 mA g⁻¹, the specific capacity still maintains 51 mAh g⁻¹, demonstrating excellent rate performance. Meanwhile, the average specific capacity of 72.5 mAh g⁻¹ was steadily cycled for 10,000 cycles at a current density of 1000 mA g⁻¹, showing excellent cycle performance. This work provides a novel approach to the high-value-added application of spent graphite from lithium batteries and a development of high-performance graphite cathode materials for AIBs.