Effective Methodology for Selective Recovery of Lithium Values from Discarded Li-Ion Batteries

The study discloses an effective methodology for selective recovery of lithium (Li) content from the cathode material of assorted types of discarded Li-ion batteries. The complex stoichiometry of cathode composition of batteries was found to be thermally reduced at an optimum temperature of 850 degrees C with 10% addition of carbon. The Li content was selectively dissolved in aqueous media using sodium persulfate (Na2S2O8) as an oxidant. The effect of varying time, temperature, and molar concentration of Na2S2O8 for Li dissolution/leaching was systematically studied. It was observed that more than 99% Li can selectively be dissolved in 0.2 M Na2S2O8 at an optimum temperature of 80 degrees C and in 4 h time from reduced cathode material, whereas only similar to 32% Li extraction was achieved for as-received cathode materials using the same optimum parameters. Finally, lithium carbonate (Li2CO3) was recovered through precipitation by adjusting the pH value of the lixiviant using sodium carbonate. The recovered Li2CO3 powder was found to have a purity of more than 99% and can be used as a precursor for battery cathode composition and other potential applications with a view to improving resource efficiency and the circular economy.