Separation and Recovery of Valuable Metals from Ammonia Leaching Solution of Spent Lithium-Ion Batteries

A sustainable route composed of solventextraction and ammoniadistillation was proposed to efficiently recover Li, Ni, Co, and Cufrom the ammonia leaching solution. The ammonia leaching system has gained widespread usagein thehydrometallurgical processing of spent lithium-ion batteries (LIBs)due to its exceptional selectivity. In this work, a novel processwas developed to recover Li, Ni, Co, and Cu from the NH3 & BULL;H2O-(NH4)(2)CO3 leaching solution of spent LIBs. First, solvent extraction usingMextral 54-100 was employed to selectively recover more than 98% ofNi and Cu, with subsequent stepwise stripping of the organic phaseusing 15 g/L and 60 g/L H2SO4 to prepare NiSO4 and CuSO4 products, respectively. The processrealizes the selective separation and recovery of Ni and Cu. Later,the ammonia distillation process was applied to recover Li and Cofrom the raffinate. Approximately 93% of Co and 64% of Li were precipitatedin the form of amorphous Co-bearing carbonate and Li2CO3, respectively. After adjusting the mole ratio of Li and Coin the precipitation to 1, the LiCoO2 cathode materialwas obtained via two-stage roasting, exhibiting excellent electrochemicalperformance. The collaborative recovery of Li and Co and the closed-loopcirculation of ammonia are realized by ammonia distillation. Moreover,the residual liquid can also return to the ammonia leaching stage,thus avoiding resource waste and the generation of wastewater.