Recovery of Co and Li from spent lithium-ion batteries by combination method of acid leaching and chemical precipitation

Cathode material of spent lithium-ion batteries was refined to obtain high value-added cobalt and lithium products based on the chemical behaviors of metal in different oxidation states. The active substances separated from the cathode of spent lithium-ion batteries were dissolved in H2SO4 and H2O2 solution, and precipitated as CoC2O4·2H2O microparticles by addition of (NH4)2C2O4. After collection of the CoC2O4·2H2O product by filtration, the Li2CO3 precipitates were obtained by addition of Na2CO3 in the left filtrate. The experimental study shows that 96.3% of Co (mass fraction) and 87.5% of Li can be dissolved in the solution of 2 mol/L H2SO4 and 2.0% H2O2 (volume fraction), and 94.7% of Co and 71.0% of Li can be recovered respectively in the form of CoC2O4·2H2O and Li2CO3.