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

Abstract

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.