Separation and recovery of valuable metals from spent lithium ion batteries: Simultaneous recovery of Li and Co in a single step

Sustainable recovery of metals from spent lithium-ion batteries (LIBs) may be of great significance regarding the conservation of metal resources and alleviation of potential risk towards eco-system. Herein an environmentally benign process was proposed for the recovery of high value-added metals (Co and Li) from typical waste cathode materials (LiCoO2) of spent LIBs using mild tartaric acid as both leaching and precipitating reagent. Leaching results indicate that Co and Li can be effectively separated under experimental conditions of reaction temperature- 80 °C, retention time- 30 min, pulp density- 30 mL/g, reducatant dosage- 3 vol% H2O2 and acid concentration- 0.6 mol/L. After leaching, 98% Co and 97% Li can be recovered as precipitate and Li+ enriched solution, respectively. And the leaching of Co and Li fits well to logarithmic rate model, with apparent activation energy of 34.5 and 29.7 KJ/mol, respectively. In addition, characterization results (i.e. FT-IR, SEM-EDS and TGA-DSC) suggest that Co can be directly recovered as relatively pure cobalt tartrate (C4H4O6Co, with a purity of 96.4%) in leaching residues. This whole process can be a sustainable alternative for the simultaneous recovery of Li and Co from waste cathode materials of spent LIBs.