Upcycling Spent Graphite into Fast-Charging Anode Materials through Interface Regulation

Abstract

Recycling the graphite anode is essential for both environmental protection and resource sustainability in lithium-ion batteries. Current recycling strategies emphasize closed-loop recovery but ignore the potential for value-added utilization. Herein, we present an upcycling strategy that converts spent graphite into fast-charging graphite. By creating an isotropic ion transport pathway on the surface of spent graphite and utilizing the fast ion migration channel inherent in the bulk’s defect structure, a direct upgrade of spent graphite for fast charging is achieved. A proposed structure model, derived from spent graphite, shows improved fast-charging performance at the particle and electrode levels. Regenerated graphite demonstrates a high specific capacity of 220 mAh g^–1 at 4C, approximately 2.8 times higher than that of commercial graphite (80 mAh g^–1), with 73% of capacity retention after 300 cycles. This work provides fundamental insights into upcycling spent graphite, featuring short production processes and great economic and environmental benefits.