From spent graphite to recycle graphite anode for high-performance lithium ion batteries and sodium ion batteries

Nowadays, recycling cathode materials form spent lithium ion batteries (LIBs) has attracted widespread attentions in order to recover highly-valuable metal elements. However, recycling graphite materials is usually discarded because of the low added value and rigorous separation steps. In this study, we investigate the possibility of reusing spent graphite as anode material for LIBs and SIBs after reconstruction process. Benefiting form the structural reconstruction process, which can enhance the interlayer force and reduce the interlayer lattice distance of graphite, lead to the reconstructed graphite with improved and stable layered structure. When used as anode materials for LIBs, the reconstructed graphite exhibits outstanding electrochemical performance. As a result, the reconstructed graphite can deliver high capacity of 427.9 mAh g−1 after 200 cycles at 0.5 C, and also display a outstanding rate capability (a capacity of 114.9 mAh g−1 is achieved at 3 C). Furthermore, the acid-treated graphite can be directly used as anode material for SIBs, which exhibit high reversible capacity of 127 mAh g−1 at 50 mA g−1, and also exhibits excellent long cycle life (a reversible capacity of 106.8 mAh g−1 is achieved after 500 cycles at 2000 mA g−1 with high capacity retention of 90.98%).