Researchers in Spain have developed a two-stage lithium recovery process applied to two different black masses from NMC 622 electric vehicle batteries after prior crushing and separation stages.

In the first stage, hydrolysis is used to extract lithium compounds from the degradation products of the electrolyte (LiPF6). In the second stage, a carbothermic reduction process is carried out in which various reducing agents are evaluated. The result of this stage is a product that is leached with water and crystallised by evaporation.

The result of the first stage is two industrially useful compounds: LiF, which is used in the production of lithium-ion battery electrolytes, and Li₃PO₄, which is used in the production of lithium-iron-phosphate batteries.

In the second stage, Li₂CO₃ is recovered with a remarkably low LiF content, with a purity higher than 98.4 %. This process allows 90–94 % of the total lithium in the black mass to be recovered.

An open-access paper on their work is published in Journal of Power Sources.

Alcaraz et al.

Resources

• Lorena Alcaraz, Olga Rodríguez-Largo, Gorka Barquero-Carmona, Félix A. López, “Recovery of lithium from spent NMC batteries through water leaching, carbothermic reduction, and evaporative crystallization process,” Journal of Power Sources, Volume 619, 2024, doi: 10.1016/j.jpowsour.2024.235215