Abstract:

The rapid growth of lithium-ion batteries (LIBs) has generated increasing amounts of discarded graphite anodes, making high-value regeneration crucial for resource circularity and sustainable manufacturing. Here, we propose a sucrose-assisted strategy to repair defects and purify failed graphite using biomass-derived carbon and a temperature-gradient high-temperature carbonization route. Compared with conventional acid leaching, the sucrose-based process offers clear advantages in cost effectiveness and eco-friendliness. Regeneration conditions were systematically screened, and an optimal temperature window was identified. The regenerated graphite treated at 1200 °C delivers the best overall electrochemical performance, achieving an initial coulombic efficiency of 88.43% and a reversible capacity of 331.8 mAh g⁻¹, together with markedly improved cycling stability compared with other temperature-gradient products and the failed graphite. The superior performance is attributed to the favorable co-evolution of the amorphous carbon coating and graphite framework at 1200 °C, which effectively heals defects, mitigates impurity-related degradation, and stabilizes the electrode interface. This work provides a simple, scalable, and greener alternative for recycling discarded graphite anodes.

Key words: Spent lithium-ion batteries, Discarded graphite, Recycled Graphite, Recycling and Regeneration, Carbon neutrality