Recycling lithium-ion batteries: A review of current status and future directions

Lithium-ion batteries (LIBs) have become a widely adopted energy source for various electrical devices, ranging from small devices to large machines, such as cell phones, and electric vehicles (EVs). The increasing number of EVs, and other electrical devices has led to the enormous amount of discarded spent LIBs into the landfill. The amount of LIB waste generated in 2019 alone from EVs was 500,000 tons. This amount is expected to reach 8,000,000 tons by 2040. Globally, only 5 % of discarded spent LIBs is presently being recycled. The need to recycle LIBs stems from the desire to conserve raw materials, and save cost. Also, LIBs comprise heavy metals (Ni, Li, Co, Cu, Mn, Fe, and Al), and hazardous chemicals, which cause serious environmental hazards and threaten human lives; thus, pointing out the need to recycle LIBs. This work reviewed different recycling techniques and, the latest technological advancements in pretreatment methods, hydrometallurgy, pyrometallurgy, and direct recycling methods. Also, future perspectives and prospects are provided herein.