A sustainable delamination approach for simultaneous separation and leaching of cathodes from end-of-life Li ion batteries

Abstract

The increasing demand for Lithium-ion batteries (LIBs) in several applications has led to a substantial rise in their production, posing risks in the supply of critical raw materials (CRM, e.g.: Li, Ni, Co). Additionally, improper disposal of end-of-life batteries can lead to environmental pollution and loss of technological value stressing the necessity for sustainable recycling. Current methods involve shredding batteries into a black mass, further processed via pyrometallurgy (energy-intensive) and/or hydrometallurgy with inorganic acids (environmentally hazardous) to recover CRMs. A more refined approach to LIBs recycling includes the dismantling and the sorting of their components, allowing for a targeted extraction.

The spent cathodes recycling process here presented involves the simultaneous delamination from the current collector and the leaching (>95 %) of the cathode active material (CAM) in a citric acid solution, enabling also the recovery of Polyvinylidene fluoride (PVDF) and Carbon filler as unleached residues, which can be used as a composite binder for new electrodes manufacturing. Lastly, metals are recovered with high yields (>85 %) as precursors, used to resynthesise fresh CAM and close the recycling loop. To validate the proposed strategy, the recycled CAM was used in a new cathode manufacturing followed by its functional characterization in a half-cell configuration, achieving high coulombic efficiencies (>99.2 %) and satisfying specific capacities upon cycling (initial capacity: 115 mAh g⁻¹).