A closed-loop process to recover Li and Co compounds and to resynthesize LiCoO₂ from spent mobile phone batteries

In the last decades, the demand for lithium-ion batteries (LIBs) has been growing fast to attend the markets of electric and hybrid vehicles and of electric portable devices. As scarce metals like cobalt and lithium are employed in their manufacturing the recycling of spent LIBs is a strategic solution for the sustainability of these minerals and also the maintenance of the LIBs production. Therefore, efforts should be driven to produce low cost, environment-friendly and industrially scalable recycling processes. In this study, a closed-loop process with these characteristics was developed to recover cobalt and lithium compounds from LiCoO₂ cathodes of spent cell phone lithium-ion batteries. The process employs citric acid as green leaching agent to recover cobalt as CoC₂O₄.2H₂O and Co₃O₄ and lithium as Li₂CO₃. Lithium compound was recovered from a proposed new and original method based on simple chemical procedures as evaporation-calcination and water dissolution. The developed process also allows the resynthesis of LiCoO₂ as a stoichiometric, well crystallized and structurally ordered compound from the recovered Co and Li compounds, in a closed-loop recycling process. The obtained results indicate that the developed process has great potential to be scaled up to a recycling industrial plant of spent lithium-ion batteries.