With the promotion and popularization of new energy vehicles, the installed amounts of lithium-ion batteries have exploded, followed by a large number of lithium batteries scrapped and urgently need to be recycled. There is a certain amount of transition metals in the residue after extracting lithium, nickel, cobalt, and manganese. If these residues are disposed directly into the environment without treatment, it would cause serious environmental pollution. In this study, a kind of catalyst (NCM1) with core-shell structure was prepared by mixing the residue with melamine. Both NCM1 and the original residue were fully characterized. It was confirmed that NCM1 has an obvious core-shell structure, with the core consisting of nickel-cobalt nitrite and manganese oxide, and the shell consisting of a graphitized carbon layer with a thickness of about 5.7-13.1 nm. Using peroxymonosulfate as oxidant, the catalytic performance of NCM1 was tested. It was found that NCM1 can efficiently catalyze PMS to degrade a series of organic pollutants, including benzoic acid, nitrobenzene, phenol, etc., and was slightly affected by environmental conditions than traditional free radical degradation system. Results of cyclic experiments show that NCM1 can be recycled several times with stable catalytic efficiency. Minor metal ions were dissolved after the degradation in NCM1/PMS system while a large amount of metal ions were dissolved in the original residue/PMS system, indicating that the metal ions in the residue can be effectively fixed through the mixed pyrolysis with melamine. Additionally, a series of experiments including quenching experiments, D2
O replacement and EPR test proved that sulfate radical and singlet oxygen made contribution to the degradation of pollutants in the system of NCM1/PMS, but there still are unexplored mechanisms.