Efficient recycling of lithium-ion batteries (LIB) is required to meeting future demand of materials and support sustainable decarbonized energy systems. At the center of the recycling process is the recovery of valuable active metals in LIBs. Hydrometallurgical recovery processes are considered cleaner and less expensive than pyrometallurgical processes, and we previously reported a hydrometallurgical process for the leaching of valuable metals in mixed shredded LIBs. [1] In this process the reductant Fe²⁺, at low concentration, is electrochemically regenerated to complete the leaching of metals of interest Co, Ni, Li, Mn, and removal of Cu from LIB black mass, eliminating the need of H₂O₂. To accelerate this process and reduce chemical and energy consumption, the effect of process variables needs to be better understood. In this work, we study the effect of added electrochemical mediator concentration (Fe), total current and agitation level on the kinetics and leaching efficiency the EC-leaching process. Moreover, we propose a new multi-stage leaching scheme for the adjustment of final pH and recirculation of iron in the system.

References

1. Diaz, L.A., et al., Electrochemical-assisted leaching of active materials from lithium ion batteries. Resources, Conservation and Recycling, 2020. 161: p. 104900.