A Simplified Process for Recovery of Li and Co from Spent LiCoO2 Cathode Using Al Foil As the in Situ Reductant

The rapid growth in demand for lithium ion batteries (LIBs) results in the generation of a vast amount of spent LIBs. Recovery of valuable metals from spent LIBs is required in terms of environmental protection and natural resource conservation. Here, we developed a novel process for the sustainable recovery of Li and Co from spent LiCoO2 cathodes based on in situ reductive roasting. In the operation of reductive roasting, Al foil in the cathode performs as an in situ reductive reagent converting LiCoO2 into Li2O, CoO, and Al2O3. Lithium and aluminum in roasting products can be selectively leached in a NaOH solution with a leaching efficiency of 93.67% and 95.59%, respectively. In the meantime, cobalt, in the form of CoO, is concentrated in the alkaline leaching residue, which can be completely dissolved in H2SO4 solution. The obtained CoSO4 solution with Co concentration higher than 160 g/L is beneficial for the following evaporation and crystallization operation. Comparing with traditional processes, the present in situ reductive roasting process features as no need for separation of active materials from Al and none external reductants adding, which can make the recycling process of spent LIBs simpler, more sustainable, and more economical.