Intensification of lithium carbonation in the thermal treatment of spent EV Li-ion batteries via waste utilization and selective recovery by water leaching

Abstract

The recycling of lithium-ion batteries remains an essential question, the recovery of lithium is a central matter since the European Commission identified it as a critical raw material. This article proposes a more effective technology in which lithium will be recovered as lithium carbonate earlier in the recycling process using thermal pre-treatment and water leaching. Two thermal treatments are compared: incineration and pyrolysis, the whole cell (cathode, anode, current collector foils, and separator) is thermally treated in a first route, while the separator is removed, in a second route. The separator's presence showed a significant positive effect on the recovery, with an optimal recovery of 62% after pyrolysis at 700°C for 1 h and water leaching at 25°C with a solid-liquid ratio of 1:50 g/ml. Under these conditions, the solution purity was 92%, and aluminum was leached together with lithium. After evaporation, lithium carbonate and fluoride are found in the residue.