A review on recycling of spent lithium-ion batteries

Lithium-ion batteries (LIBs) with high power density are commonly used in electric vehicles and portable electronic devices. Their applications have been soaring in recent years resulting in an increasing number of used LIBs. Spent LIBs containing heavy metals and toxic hazardous are becoming a severe threat to the environment and human health which must be addressed properly. Recycling is an option for end-of-life LIBs, which not only prevents the pollution of toxic components but also saves natural sources. This paper introduces battery structures and gives an overview of the current state of waste LIBs and their recycling status. Moreover, recent advancements in hydrometallurgy, pyrometallurgy, and direct recycling at both research and industrial levels are deeply analyzed. This document can serve as a useful reference resource for researchers or engineers, who might profit from applying the concept to the examples summarized in the comprehensive review paper.