Enhanced Leaching of Lithium-Ion Battery Cathode Scraps with In Situ Electrogenerated Persulfates

A sustainable and efficient leaching procedure using electrochemistry for recycling cathode scraps from lithium-ion batteries (LIBs) is demonstrated. The additional use of chemicals, except the leaching medium itself, is avoided by in situ electrogeneration of peroxydisulfate from sulfuric acid on a boron-doped diamond (BDD) electrode. The leaching of LCO, NCM, and black mass with and without the addition of persulfates (peroxymono- and disulfate) was investigated in detail. Using persulfates as salts at 65 °C, the conversion rate of cobalt almost doubled to 83%. When leaching NCM, the cobalt, nickel, and manganese conversion rates increase significantly to achieve almost quantitative conversion. When persulfates were in situ electrogenerated, even lower concentrations were efficient for leaching LCO and NCM. The use of persulfates also substantially accelerates the leaching of all valuable metals of industrial black mass, which is completed in under 5 min.