Direct and rapid thermal shock for recycling spent graphite in lithium-ion batteries

Due to the rapid increase in the number of spent lithium-ion batteries, there has been a growing interest in the recovery of degraded graphite. In this work, a rapid thermal shock (RTS) strategy is proposed to regenerate spent graphite for use in lithium-ion batteries. The results of structural and morphological characterization demonstrate that the graphite is well regenerated by the RTS process. Additionally, an amorphous carbon layer forms and coats onto the surface of the graphite, contributing to excellent rate performance. The regenerated graphite (RG-1000) displays excellent rate performance, with capacities of 413 mAh g^-1 at 50 mA g^-1 and 102.1 mAh g^-1 at 1000 mA g^-1, respectively. Furthermore, it demonstrates long-term cycle stability, maintaining a capacity of 80 mAh g^-1 at 1000 mA g^-1 with a capacity retention of 78.4 % after 600 cycles. This RTS method enables rapid and efficient regeneration of spent graphite anodes for lithium-ion batteries, providing a facile and environmentally friendly strategy for their direct regeneration.