2024 AIChE Annual Meeting
Effects of Intrinsic Impurities on Hydrothermal Relithiation for NCM811 Regeneration
The increasing use of lithium-ion (Li-ion) batteries necessitates efficient recycling methods to mitigate environmental impact and resource depletion. While hydrothermal relithiation, a method of direct recycling, has shown promise in laboratory settings for regenerating NCM811 (LiNi0.8Co0.1Mn0.1O2) cathodes, scaling this method to industrial levels remains challenging due to the need to address and remove impurities, such as binder residues and conductive additives in spent materials. These impurities, which vary in concentration across different spent cathode materials, have not yet been systematically studied. Our research focuses on understanding how different levels of inherent carbon binder impurities affect the hydrothermal relithiation process. This was accomplished through analysis of NCM811 materials with varying percentages of Polyvinylidene Fluoride (PVDF) after hydrothermal relithiation. Increasing percent of impurities lead to a less fully lithiated product. Temperature can also be optimized to aid the relithiation and limit effects of PVDF impurities. By systematically investigating the impact of these impurities, we aim to develop scalable relithiation parameters that maintain efficiency and effectiveness despite the variability in industrial-grade materials.