Engineering a tandem leaching system for the highly selective recycling of valuable metals from spent Li-ion batteries†
With the rapid development of lithium-ion batteries (LIBs), the selective recovery of lithium and other valuable metals from spent LIBs is in urgent need because of the shortage of Li and valuable metals along with the toxicity of components. Herein, a tandem leaching system for the selective recovery of Li and other valuable metals (Co, Mn) from spent LIBs was engineered by employing formic acid and its derived deep eutectic solvent (DES) as leaching agents. Results illustrate that Li can be selectively leached by formic acid, and other valuable metals can be recycled by DES. The selective leaching of valuable metals from different types of LIBs were investigated, and it was found that the tandem leaching system was applicable to the different types of LIBs with recovery efficiencies >99% for valuable metals at leaching temperatures as low as 70 °C. This finding may provide an environmentally friendly and effective approach for the selective recovery of Li and other valuable metals from spent LIBs.