Critical Review of Thermal Reduction Processes for Sustainable Recovery of Valuable Metals From Cathode Materials in Spent Lithium‐Ion Batteries

With the widespread adoption of LIBs across various applications, the volume of spent batteries rapidly increases, posing environmental challenges and resource recovery opportunities. Pyrometallurgical recycling has emerged as a promising and efficient approach for recovering valuable materials, gradually becoming a mainstream method for end‐of‐life LIBs treatment. Among the various pyrometallurgical techniques, thermal reduction stands out due to its high efficiency in metal recovery. However, its economic viability and environmental impact remain inadequately understood. This review systematically examines the fundamental principles and reaction mechanisms of three primary thermal reduction processes: pyrolysis, carbothermic reduction, and other thermal reduction methods. A comprehensive life cycle assessment (LCA) and economic cost analysis are conducted for each method. The results reveal that each process exhibits distinct advantages regarding recovery efficiency, energy consumption, and environmental performance, reflecting their respective application potentials. Finally, the review discusses the key challenges and critical considerations associated with thermal reduction recycling and provides insights into the future development trends and industrial prospects of battery recycling technologies.