Electrochemically-assisted leaching of active cathode materials from spent batteries with minimal pre-treatment using hydroxylated solvents☆

resumo

Spent lithium-ion batteries (LIBs) are a rapidly increasing source of waste that pose a hazardous and environmental problem. They are also a secondary source of valuable critical metals such as Li, Co, Ni and Mn. Their recycling often involves use of aggressive conditions, which challenge the sustainability character of the process. In this work, an electrochemically-assisted leaching process was carried out to dissolve valuable metals from pristine and spent LIB cathode materials under mild conditions without the need for any pre-treatment (removal of polymeric binder and current collector). Hydroxylated solvents were used as electrolytes, firstly in leaching of Co3O4, demonstrating that the applied potential played a determinant role in achieving high Co dissolution (73.1 %). Subsequently, real spent cathodes were directly used, without pre-treatment, as working electrodes under mild working conditions. Up to 82 % Li, 62 % Co, 60 % Ni and 52 % Mn were leached at potentials up to 3 V with fast kinetics in the first 30 min of the process. The structural changes caused by initial delithiation of the black mass, corrosion of the Al from the current collector, and the presence of binder, were identified as key in achieving competitive metal leaching efficiency values. This process can pave the way for new LIB recycling processes with less pre-treatment requirements, in milder conditions while still being scalable to an industrial setting.

palavras-chave

ALUMINUM DISSOLUTION; VALUABLE METALS; LITHIUM; RECOVERY; MANGANESE; COBALT; KINETICS; NICKEL; SEPARATION; SPECIATION

categoria

Engineering

autores

Bastos, H; Schaeffer, N; Pringle, JM; Eftekharnia, M; Coutinho, JAP; Pozo-Gonzalo, C

Grupos

G4 - Materiais Renováveis e Economia Circular

Projectos

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

NMC - Novos Materiais Celulósicos (NMC)

agradecimentos

This work was partly developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020, and LA/P/0006/2020, financed by national funds through the FCT/MCTES. H. Bastos acknowledges the financial support from Deakin University (DUPR Scholarship 0000038986) . The authors acknowledge the Australian Research Council (ARC) Training Centre for Future En-ergy Storage Technologies (storEnergy) (IC180100049) for funding. Financial support from EU (IONBIKE 2.0 MSCA-SE grant agreement No 101129945) is also acknowledged. A special thanks to Dr. Mojtaba Eftekharnia and Dr. Meisam Hasanpoor, from Battery Research and Innovation Hub in Melbourne, Australia, for assembling and providing the NMC622 pouch cells and dismantling the cells for further work, respectively. We are equally grateful to Andre Nogueira from the Chemistry Department of the University of Aveiro for the preparation and analysis of the ICP-OES samples regarding the kinetic study of electrochemically-assisted leaching of the spent NMC 622 cathodes.