Application and recycling of lithium-ion batteries

As an emerging technology with a vast worldwide market application and potential over decades, electric vehicles (EVs) have played a significant role in human society to prevent the deterioration of the environment. Meanwhile, the research on lithium-ion batteries (LIBs) in EVs improving their performances, including energy density and cycle life, has recently attracted much attention, aiding the further development of the functions of EVs. This research can be divided into three parts. Firstly, the fundamental of LIBs is presented, including its theory and reasons for having low energy density. Then, the alternative Li-S battery technology employed for EVs is introduced, and its advantages and limitations for future research are illustrated. Lastly, the three main approaches for recycling used LIBs, pyrometallurgical recovery (Pyro.), hydrometallurgical metals reclamation (Hydro.) and direct recycling (Dir.) are elaborated, each of their strengths and weaknesses are shown, and their performances are compared by considering several aspects for selection.