Abstract
Due to the lack of adapted competitive recycling methods, Lithium-ion Batteries (LIB) production scraps are currently treated as spent batteries, despite their significant difference in characteristics. However, with the drastic increase in LIB production and consequently, the generation of scraps, various innovative recycling techniques have emerged and gained significant attention, aiming to offer greener, cheaper and more direct recycling routes. This study explores a novel solvent-based delamination method that employs a mixture of triethyl phosphate (TEP), acetone, and carbon dioxide (CO2) under pressure and temperature, for the direct recycling of positive electrode production scraps. Optimization of experimental conditions led to achieve a full delamination within 15 minutes at 120°C and 100 bar, with an exceptionally low solvent consumption of 1.5 of TEP to electrode ratio (w/w). The properties of pressurized fluids enhanced the kinetics of delamination while removing the need for stirring and reducing the solvent consumption (by 6.7x), showing a huge advantage compared to other state-of-the-art delamination techniques. Subsequent to the process, the active material LNi0.6Mn0.2Co0.2O2 (NMC622) was easily separated from the current collector, enabling a comprehensive characterization. A more in-depth focus on the electrochemically active material revealed that its chemical composition, crystal structure, and microstructure remained preserved throughout the recycling process. Ultimately, the electrochemical performance of the recycled NMC622 closely resembled that of pristine NMC622, affirming the promising potential of this approach.