Comparative performance analysis of NMC cathodes elaborated from recovered and commercial raw materials: A low-temperature molten salt approach for extracting critical metals from end-of-life lithium-ion batteries

Abstract

Recycling end-of-life (EoL) Lithium-ion batteries is crucial in maintaining the economic and ecological balance. It allows the proper management of the hazardous elements and recovering critical elements such as Li, Co, Ni, and Mn. In the study, a fully eco-friendly recycling process that utilizes a molten salt process (ammonium sulfate) to regenerate lithium, nickel, manganese and cobalt from active materials used in motorcycle batteries, obtained from a local e-mobility company, was developed. The roasting and leaching parameters of the recovered black mass were optimized in order to recover pure NixMnyCoz(OH)2 and Li2CO3. The use of (NH4)2SO4 enabled attaining high recovery yields of Li, Mn, Ni, and Co, with rates of 95.4 ± 0.3%, 94.8 ± 0.6%, 93.4 ± 0.4%, and 92.6 ± 0.5%, respectively. These recovered products were utilized in the synthesis of three different novel cathode active materials (LiNixMnyCozO2) (CAMs). Furthermore, aluminum used as the current collector was also recovered, promoting the process's eco-friendly aspect. The morphological and structural properties of the novel CAMs phases were compared to those prepared from commercial raw products, which they perfectly match. The specific discharge capacities of regenerated cathodic materials from recovered metals were benchmarked, and they were found to be approximately 180 mAh.g−1 and 135 mAh.g−1 at 0.2 C and 0.5 C, respectively, which are comparable to capacities provided by materials synthesized from commercial reagents. Through investigating the electrochemical performance of various regenerated CAMs, the feasibility of utilizing recycled precursors as an alternative to commercial reagents was established for the synthesis of multiple battery chemistries.