Advances of deep eutectic solvents in lithium battery recycling field

In the era of carbon neutrality and digital transformation, the increasing integration of new smartphones, computers, and electric vehicles into daily life has led to a surge in spent batteries, which, if improperly managed, pose significant environmental risks. Among all types of batteries, lithium-ion batteries (LIBs) are widely used due to their high energy density. The cathode materials of LIBs, typically composed of lithium iron phosphate, lithium nickel cobalt manganese oxide, and lithium cobalt oxide contain substantial amounts of valuable metals. Consequently, the recycling and reuse of these cathode materials have garnered significant research interest. However, existing recycling methods often present environmental and economic challenges. Deep eutectic solvents (DESs), known for their environmental friendliness and designable propertied, have drawn much attention for recycling the cathode materials of spent LIBs and have been made some progress. This article focuses on summarizing the current work related to the use of DESs to recycle the cathode materials of LIBs and classifying them according to different electrode materials. In addition to the recovery of cathode materials, DESs also have certain applications in the recovery of anode materials and the removal of adhesive in LiBs, which have been discussed in the manuscript. We compared the performance of various types of DESs for LIBs recovery under different conditions. We also summarized the advantages and common problems of the current related work and give relevant directions that can be improved in the future.