Recycle spent graphite to defect-engineered, high-power graphite anode

Graphite is a dominant anode material for lithium-ion batteries (LIBs) due to its outstanding electrochemical performance. However, slow lithium ion (Li⁺) kinetics of graphite anode restricts its further application. Herein, we report that high-temperature shock (HTS) can drive spent graphite (SG) into defect-rich recycled graphite (DRG) which is ideal for high-rate anode. The DRG exhibits the charging specific capacity of 323 mAh/g at a high current density of 2 C, which outperforms commercial graphite (CG, 120 mAh/g). The eminent electrochemical performance of DRG can be attributed to the recovery of layered structure and partial remaining defects of SG during ultrafast heating and cooling process, which can effectively reduce total strain energy, accelerate the phase transition in thermodynamics and improve the Li⁺ diffusion. This study provides a facile strategy to guide the re-graphitization of SG and design high performance battery electrode materials by defect engineering from the atomic level.