Recovery of high-value metals from the cathode of spent lithium-ion batteries via acid leaching: A review

Abstract

Lithium-ion battery (LIB) technology must continue to advance to achieve greenhouse gas emission reduction goals. As the demand has grown, the quantity of used LIBs has significantly increased, creating opportunities for battery recycling industries to supply critical metals. Currently, only about 2 million tons of spent LIBs are recycled globally each year. Therefore, a fundamental shift in recycling processes to handle diverse battery chemistries is required to transform the current state of recycling. Acid-based hydrometallurgical processes are the most commonly used and promising techniques for recovering precious metals from spent LIBs. However, developing a sustainable and effective approach for the complete recovery of these resources from the multi-component leachate of LIBs after acid leaching is still challenging. This review paper systematically summarizes the present strategies for recovering high-valued metals from acid-leached liquors of spent LIBs. Taking the current status of the processes, the review also further suggests directions for their better development and future applications. The integration of different metal separation methods can simplify operations, improve the recovery of valuable resources, and boost the scale-up development. Overall, this review provides a systematic overview of acid leaching and metal recovery processes from spent LIBs, with the aim of advancing the greening and sustainability of acid-based hydrometallurgical processes.