Recent advances in preferentially selective Li recovery from spent lithium-ion batteries: A review

The extraction of lithium (Li) from spent Li-ion batteries (LIBs) can alleviate the shortage of primary raw materials and therefore benefit environmental and economic aspects. However, current Li recovery strategies from spent industrial LIBs result in low Li recovery and purity, because Li recovery is usually conducted after the recovery of Ni, Co, and Mn. In the last few years, preferential selective Li extraction has attracted attention for tackling the shortage of Li resources. In this review, we present current advances in preferentially selective Li extraction technologies for treating spent LIB cathode materials. After introducing the reaction principles and mechanisms of the different recovery methods such as hydrometallurgical processes, combined pyro-hydrometallurgical processes, electrochemistry, mechanochemical methods, membrane separation, and deep eutectic solvent leaching, the advantages and disadvantages of each method are evaluated. Analysis of the available data revealed that the preferential recovery of Li via hydrometallurgical processes and combined pyro-hydrometallurgical processes may be the most viable methods for industrialization. This review offers insights into the environmental and economic benefits of the different preferentially selective Li extraction processes. Furthermore, it provides references for subsequent research and insights for further developments in industrial practices related to selective Li recovery from spent LIBs.