NCM cathode active materials reproduced from end-of-life Li-ion batteries using a simple and green hydrometallurgical recycling process

LiNi1/3Co1/3Mn1/3O2 (NCM 111) cathode material was reproduced from end-of-life lithium-ion batteries (LIBs) via a green hydrometallurgical process including environmentally friendly DL-malic acid leaching, oxalate co-precipitation, and heat treatment. The leaching reached 95% efficiency by using glucose as reducing agent. X-ray fluorescence analysis revealed effective oxalate co-precipitation of metal ions in the form of MC2O4∙2H2O (M = Ni, Co, Mn) with Ni, Co, and Mn ratio was approximately 1:1:1. Heat treatment on the mixture of precipitateand lithium salt at 900 ℃ successfully reproduced NCM 111 cathode as confirmed via x-ray diffraction characterization. This sample also demonstrated comparable electrochemical properties with the fresh NCM cathode powder, with an initial specific discharge capacity of 158 mAh/g (0.2 C) and high rate capabilities. After 100 cycles of charge-discharge measurement at 0.2 C, this sample also revealed stable cycling ability with capacity retention of 93%, ensuring the good features of the reproduced cathode.