Recovery of valuable metals from mixed spent lithium-ion batteries by multi-step directional precipitation

The novel strategy of multi-step directional precipitation is proposed for recovering valuable metals from the leachate of cathode material obtained by mechanical disassembly from mixed spent lithium-ion batteries. Based on thermodynamics and directional precipitation, Mn(2+) is selectively precipitated under conditions of MRNM (molar ratio of (NH(4))(2)S(2)O(8) to Mn(2+)) = 3, pH = 5.5 and 80 °C for 90 min. Ni(2+) was then selectively precipitated using C(4)H(8)N(2)O(2) under conditions of pH = 6, MRCN (molar ratio of C(4)H(8)N(2)O(2) to Ni(2+)) = 2, 30 °C and 20 min. Then, the pH was adjusted to 10 to precipitate Co(2+) as Co(OH)(2). Finally, Li(+) was recovered by Na(2)CO(3) at 90 °C. The precipitation rates of Mn, Ni, Co, and Li reached 99.5%, 99.6%, 99.2% and 90%, respectively. The precipitation products with high purity can be used as raw materials for industrial production based on characterization. The economical and efficient recovery process can be applied in industrialized large-scale recycling of spent lithium-ion batteries.