Research progress on green recovery technologies of valuable metals from waste lithium batteries

<p indent="0mm">With the rapid growth in new energy electric vehicles, the usage and disposal of lithium-ion batteries have surged, creating an urgency to recover valuable metals such as cobalt, nickel, and lithium. This study reviews various recovery methods for waste lithium batteries, discussing the latest research advancements in pretreatment, pyrometallurgy, hydrometallurgy, and direct regeneration techniques for recovering valuable metals from cathodes. The analysis examines the key factors influencing pyrometallurgical and hydrometallurgical recovery technologies from both thermodynamic and kinetic perspectives. It explores optimal strategies to enhance environmental sustainability and cost efficiency while maintaining high recovery rates. Particular attention is devoted to the advantages of direct regeneration processes using deep eutectic solvent systems, which enable mild leaching and regeneration of active cathode materials. These systems are evaluated for their economic feasibility and environmental impact, demonstrating their potential as sustainable recovery solutions. Finally, the paper summarizes the challenges in waste lithium battery recovery and utilization, envisioning advancements toward green and efficient closed-loop recycling systems.