Selective recovery of lithium from spent NCM lithium-ion batteries powders with ammonium sulfate roasting

Release time:2026-04-10

DOI number:10.1016/j.seppur.2025.134155

Journal:SEPARATION AND PURIFICATION TECHNOLOGY

Key Words:Spent lithium-ion batteries； Selective lithium extraction； Ammonium sulfate roasting； Conversion mechanism； Lithium fluoride

Abstract:The traditional hydrometallurgical process for the recovery of spent NCM lithium-ion batteries (NCM-LIBs) powders adopts a "Mn-Co-Ni-Li" stepwise separation and extraction strategy. However, Li tends to disperse during the separation of Mn-Co-Ni, resulting in low Li recovery. This study aims to precisely control the phase transformation of valuable metals via ammonium sulfate roasting, ensuring that Li in LiCo0.5Ni0.2Mn0.3O2 (NCM523) is fully converted into water-soluble Li2SO4, while Ni, Co and Mn are primarily reduced to acid-soluble CoO and (NiO)(m)(MnO)(n). Following water leaching, similar to 91 % Li was preferentially extracted, while the leaching ratios of Ni, Co and Mn were only similar to 0 %, similar to 0% and similar to 16 %, respectively. similar to 9 % Li that failed to be leached was attributed to unconverted LiF in the spent NCM-LIBs powders. A novel tert-octyl phenyl phosphate (PTOPP) extractant enabled the deep removal of Mn from the Li-containing water-leaching solution. The extraction ratio of Mn exceeded 99 % through 3-stage countercurrent extraction. Li retained in the raffinate was precipitated with NH4HF2 to prepare battery-grade LiF (99.98 %). In this paper, a process was developed for closed-loop selective recovery of Li from spent NCM-LIBs powders, along with the conversion of transition metals into readily acid-leachable low-valent oxides.

Indexed by:Journal paper

Document Code:134155

Discipline:Engineering

First-Level Discipline:Metallurgical Engineering

Document Type:J

Volume:377

Number of Words:9

Translation or Not:no

Date of Publication:2025-12-19

Included Journals:SSCI、SCI、EI