Highly efficient recovery of lithium from spent ternary NCM cathode materials via a selective chlorination method

The recovery of lithium from spent lithium-ion batteries (LIBs) is an important approach to solve the global shortage of lithium resource. Considering the difference in stability of various metal element chlorides in Ni-Co-Mn ternary (NCM) cathode materials, lithium element was selectively and high-efficiently extracted from spent ternary NCM cathode material by ammonium chloride roasting in oxygen atmosphere followed by water leaching. The effects of roasting temperature, roasting time, and NH 4 Cl dosage on lithium leaching efficiency and selectivity were systematically investigated. In addition, the conversion mechanism during chloride roasting was discussed in detail in conjunction with thermodynamic analysis as well as structural and compositional characterizations. After roasting with NH 4 Cl in oxygen atmosphere at 600°C, the spent NCM cathode material was thoroughly decomposed and converted into mixture of LiCl, NiO, and MnCo 2 O 4 . Due to the high aqueous solubility of LiCl, more than 95 % of the lithium in the mixture was leached in ∼30 minutes at room temperature, and Li 2 CO 3 with a purity of 99.40 % can be obtained in the subsequent recovery process. This simple and efficient method can be generally useful for the recovery of a wide range of spent cathode materials and provide inspiration for the lithium recovery process of spent LIBs.