Selective leaching of lithium ions from LiFePO4 powders using hydrochloric acid and sodium hypochlorite system

Abstract High‐efficiency and selective leaching of lithium ions from spent lithium iron phosphate (LiFePO 4 ) batteries is currently an urgent problem to be solved. Hydrochloric acid and sodium hypochlorite were used as acidic media and oxidant for recycling LiFePO 4 powders based on the stoichiometric ratio. The effect of operation conditions on leaching performance was investigated. The leaching yield of Li and Fe were higher than 95% and lower than 0.1% within 20 min at 15°C. In addition, X‐ray diffraction, X‐ray photoelectron spectroscopy, scanning electron microscopy, and laser particle size analysis characterizations were applied for revealing the selective leaching mechanism, the results of which indicated that the crystal structure of powders remained basically unchanged during the leaching process. Finally, an efficient and cost‐effective recycling process for LiFePO 4 powders was proposed, and lithium carbonate products with purity higher than 99.7% were obtained. The proposed recycling process shows strong industrial application potential for LiFePO 4 powders.