摘要
Conventional chemical precipitation methods face challenges in selectively recovering valuable metals from mixed spent lithium-ion batteries (LIBs) due to the similar chemical properties of Mn, Co, and Ni. This study introduces a novel absolute chemical precipitation process for the stepwise recovery of metals, beginning with leaching followed by selective precipitation. The process achieves leaching efficiencies exceeding 90 % for Co, Ni, Mn, and Li under optimal conditions (1 h, 70 °C, 3.5 mol/L H
SO
, 8 vol% H
O
, and 20 g/L pulp density). Subsequent precipitation steps deliver high-purity recoveries of FePO
(97.22 %), MnO
(94.1 %), Co
O
·3H
O (98.7 %), Ni(OH)
(95.9 %), and Li
CO
(99.8 %), with precipitation percentages exceeding 98 %. The method is effective across diverse LIB chemistries, including LiNi
Co
Mn
O
(NCM), LiFePO
(LFP), LiM
O
(LMO), LiNi
Co
Al
O
(NCA), and LiCoO
(LCO), without requiring pre-sorting. Pilot-scale validation using a 5 kg batch of mixed spent LIB cathode and anode active materials confirmed the process's scalability and consistent high recovery efficiencies, achieving purities exceeding 90 % for all recovered metals. By utilizing low-cost, non-toxic reagents and moderate processing temperatures, this method minimizes hazardous waste generation and operational costs, offering a sustainable and scalable solution for critical metal recovery of spent LIBs.