Study on the preparation and modification of LiNi0.6Co0.2Mn0.2O2 from spent lithium ion batteries as lithium and cobalt source

Abstract

In this work, a process has been proposed to recover cobalt and lithium elements from spent LiCoO2 batteries, then these elements were used as raw materials for the synthesis of LiNi0.6Co0.2Mn0.2O2 material. In addition, aluminum ion was selected as a dopant to modify the LiNi0.6Co0.2Mn0.2O2. The obtained materials were characterized by X-ray diffraction, scanning electron microscopy, electrochemical impedance spectroscopy and charge-discharge tests. The XRD results showed that the aluminum doped material with a mass fraction of 1% had a lower degree of cation mixing and a more stable structure. Li(Ni0.6Co0.2Mn0.2)0.99Al0.01O2 cathode material provided a high discharge specific capacity of 181.82 mAh·g-1 at 0.1 C and maintained a capacity of about 92.60% after 100 cycles. When the current density was 2 C, it still retained a discharge specific capacity of 128.96 mAh·g-1, which was a huge improvement compared to that of pure LiNi0.6Co0.2Mn0.2O2. In general, it may be a good way to reduce the adverse environmental impact of landfilling spent lithium batteries by the sustainable recovery of high value-added metals in spent lithium ion batteries to synthesize new cathode materials.