Electrochemical recovery of lithium-ion battery materials from molten salts by microstructural characterization using X-ray imaging

Mateen Mirza, Wenjia Du, Lara Rasha, Steven Wilcock, Arfon H. Jones, Paul R. Shearing, Dan J.L. Brett - Electrochemical Innovation Lab, University College London, UK | The Faraday Institution, Didcot, UK | AWE, Aldermaston, UK

Recycling spent lithium-ion batteries (LiBs) guarantees the conservation of important metal resources by reducing demands on raw supply and offsetting the energy and environmental costs associated with its manufacture. Employing a molten salt as a solvent for extraction affords a much greener and simpler route to metal recovery by electrochemical means. The current mechanistic understanding of the electrochemical recovery of metals in molten salts needs to be improved for the process to be optimized. X-ray computed tomography offers a non-destructive approach for 3D microstructure visualization and subsequent quantification. Here, we study the electrochemical deposition of recovered cobalt metal from lithium cobalt oxide, LiCoO2 in LiCl-KCl eutectic (LKE). This diagnostic approach has been applied to LiCoO2-LKE samples before and after electrolysis at 450°C, yielding key insights into the morphological evolution of product formation.