A sustainable raw chemical process for metal recovery from unsorted spent lithium-ion batteries

The rapid evolution of lithium-ion battery (LIB) technologies has led to an increasingly heterogeneous end-of-life battery stream, making chemistry-based sorting a major bottleneck for recycling. In this study, we present a simple, flexible, and sustainable hydrometallurgical process for the treatment of unsorted spent LIBs, including LCO, NMC, NCA, and LFP chemistries, sourced directly from a real disposal plant. The proposed process integrates six sequential steps: safe battery deactivation, separation of active materials from current collectors, acidic leaching of the black mass, selective precipitation of transition metals, lithium recovery as lithium carbonate, and conversion of metal sulfides into sulfate salts. Lithium is recovered as Li₂CO₃ with an average yield of 85% and a purity of 97%, independently of cathode chemistry. Copper and aluminum current collectors, as well as graphite, are recovered in forms suitable for further recycling, while cobalt, nickel, manganese, and iron are obtained as valuable secondary raw materials. Importantly, the recovered products are obtained in chemical forms that are readily compatible with established hydrometallurgical and mining processes, enabling their direct integration into existing industrial value chains. A Life Cycle Assessment (LCA), performed according to ISO standards, shows that the environmental impacts of the recycling process are largely offset by the avoided burdens associated with secondary material recovery, resulting in an overall net environmental benefit. Finally, this work demonstrates an integrated and industrially compatible recycling strategy capable of treating heterogeneous, unsorted LIB waste streams, contributing to circular economy objectives and compliance with upcoming regulatory targets.