Unveiling the Control Mechanism of the Carbothermal Reduction Reaction for Waste Li-Ion Battery Recovery: Providing Instructions for Its Practical Applications

Resource recycling from waste Li-ion batteries (LIBs) can greatly relieve the pressure of resource shortage in manufacturing LIBs, helping to achieve the purpose of sustainable development. The carbothermal reduction (CR) as a proved treatment technology for waste LIB recovery has attracted much attention due to its practicality. Great efforts have been made to promote practical application of CR technology, but the related studies are insufficient and some scientific questions remain unclear. In this study, a multistage control mechanism of the CR reaction is revealed to provide instructions for promoting the resource recycling from waste LIBs. First, from roasting experiments and thermogravimetric analysis, the CR reaction interval is determined to be between 873 and 1073 K. Furthermore, detailed kinetic calculations are conducted to obtain kinetic triplets, where the reaction model is determined. The result indicates that CR reaction includes three subreactions. Then, the concept of contribution of different subreactions is applied to confirm the key subreaction at different reaction stages, which helps to unveil the control mechanism. Finally, experiments are performed to verify the control mechanism. The results indicate the targeted operations can be performed to control the CR reaction based on the control mechanism.

Automated summary

The study reveals a multistage control mechanism of the carbothermal reduction (CR) reaction to provide instructions for promoting resource recycling from waste Li-ion batteries. The reaction interval is determined through roasting experiments and thermogravimetric analysis, followed by detailed kinetic calculations to obtain kinetic triplets and confirm the reaction model consisting of three subreactions. The concept of contribution of different subreactions is then applied to identify the key subreaction at various stages and unveil the control mechanism for the CR reaction.