CO2 Treatment Enables Non-Hazardous, Reliable, and Efficacious Recovery of Spent Li(Ni0.5Co0.2Mn0.3)O2 Cathodes

The rapid demand growth of lithium-ion batteries (LIBs) will inevitably lead to a shortage of related metal resources. Recycling valuable metals from spent LIB has become imperative. Here, we propose a non-hazardous, reliable, and efficacious process for in situ recovery of valuable components from spent LiNi0.5Co0.2Mn0.3O2 cathode. First, the cathode sheets pre-acquired by disassembly are thermally treated in CO2 atmosphere, and the intact Al foils with obvious metallic luster are recovered. The lithium component (Li2CO3) is preferentially dissolved in water, and the recovery efficiency reached 92.84 %. Meanwhile, the residues concentrated with Ni, Co, and Mn components are easily dissolved in sulfuric acid solution without any additional heat treatment, and no explosive gases are generated. Then, by comparing the thermal reduction characteristics of cathode materials under different atmospheres (Air, Ar, and H2/Ar), the mechanism of pyrolysis of cathode materials under CO2 atmosphere and the role of CO2 in the thermal reduction process are systematically studied. This work not only provides a novel method for the recycling of spent cathode materials but also guarantees the safety of related personnel and properties.