Efficient Photo-Oxidation Leaching of Ni and Co in a Spent Lithium-Ion Battery Cathode by Homogeneous UV/H2O2

Existing lithium-ion battery (LIB) leaching and recycling techniques have been widely applied in industrial production despite problems, such as difficult operation, high cost, and heavy pollution. Herein, we propose a novel photochemical oxidation method to leach Co and Ni ions in spent LIB cathodes, achieving leaching efficiencies of 99.73 and 97.54% when irradiated with hydrogen peroxide as the oxidant in acetonitrile and dichloromethane as the solvent under UV light for 4 h. The oxidation mechanism of the reaction was investigated by a series of tests. Three free radical oxidation pathways that functioned together with the reaction mechanism were proposed. This study is the first to combine the UV/H2O2 photo-oxidation reaction with spent LIB recycling to achieve a universal, green, and simple operation path for metal recycling field in the future.