Efficient Regeneration of Graphite from Spent Lithium‐Ion Batteries for High‐Performance Cathode Matrix in Lithium‐Sulfur Batteries

In this work, a facile hydrometallurgical approach combined with heat treatment has been adopted to recycle spent graphite from retired lithium-ion battery cells. Graphite regenerated with 18 M H2SO4 leaching leads to a high specific surface area, significant porosity and small crystallite size. The regenerated graphite has been infiltrated with sulfur under solvothermal conditions at 160 oC. The sample containing 68 wt% of sulfur recovers a capacity of 224 mAh/g after 100 cycles. Furthermore, the electrode with a higher sulfur content of 84 wt%, recuperates the specific discharging capacity of 207 mAh/g after 100 cycles. After the initial fading during the first 5-10 cycles, the cathodes based on regenerated graphite demonstrate stable cycling behavior. This research not only offers an accessible and scalable method for regenerating graphite from spent LIBs but also demonstrates a new application of the regenerated graphite in LSBs, showcasing outstanding electrochemical performance.