Research on the Mechanism and Product of the Spent LiCoO2-Based Cathode Materials and Graphite by the Carbothermal Reduction Approach

The increasing number of spent lithium-ion batteries demands the development of efficient and environmentally friendly recycling technologies. This study explores the carbothermal reduction (CR) of LiCoO2-graphite mixtures with mass ratios of 32∶1 (Group A) and 10∶1 (Group B). Thermal analysis and kinetic models (KAS and FWO) revealed that higher heating rates shifted pyrolysis peaks to higher temperatures. Group B exhibited the greater weight loss and a higher activation energy (KAS: 240.64 kJ/mol; FWO: 234.08 kJ/mol) than Group A. Product analysis indicated that at 800°C, Group A produced Li2CO3 and CoO, while Group B yielded Li2CO3 and metallic Co. By adjusting the mixing ratio and temperature, lithium and cobalt can be selectively recovered, providing a theoretical basis for sustainable battery recycling.