Recovery of Lithium from Black Cathode Active Materials of Discarded Lithium-Ion Batteries

Abstract

Lithium (Li) is the lightest energy critical element used in manufacturing of active cathode material of lithium-ion batteries (LIBs). Thus, the consumption of lithium is constantly increasing in the LIBs. Meanwhile, LIBs become obsolete after reaching its end-of-life resulting in the generation of huge amount of spent LIBs. Present study reports the roasting and leaching process for selective recovery of Li from active cathode material. To optimize the process parameters viz. roasting temperature, time, and mass ratio studies were carried out varying the experimental conditions for the conversion of lithium oxide to lithium sulfate from the complex of lithium cobalt oxide. It was found that cathode material converted into lithium sulfate at 750 °C in two hours maintaining mass ratio of LiCoO2/Na2SO4: 1/0.5. Subsequently, 99.1% Li was leached from roasted product at 75 °C in de-ionized water within two hours. Further, Li can be precipitated as lithium carbonate using sodium carbonate.