High‐Selectivity Recycling of Valuable Metals from Spent Lithium‐Ion Batteries Using Recyclable Deep Eutectic Solvents

Abstract The recovery of valuable metals from spent lithium‐ion batteries using deep eutectic solvents (DESs) is an environmentally and economically beneficial process. In this study, a method has been developed for recovering LiNi 0.33 Co 0.33 Mn 0.33 O 2 . Our process operates under mild conditions and with a little oxalic acid as a reducing agent, dissolving lithium, cobalt, manganese, and nickel completely utilizing a DES that is composed of tetrabutylammonium chloride and of monochloroacetic acid. Lithium and nickel were selectively precipitated using oxalic acid. Cobalt and manganese were precipitated as oxalates by adding an oxalic acid aqueous solution. Finally, the DES can be regenerated by evaporating the water. Importantly, valuable metals can be recovered with a 100 % yield through the process of DES recycling. This environmentally friendly and recyclable process is suitable for the recycling of spent lithium‐ion batteries industry.