EXTRACTION OF LITHIUM METAL FROM LITHIUM-ION BATTERY RECYCLING USING CHOLINE CHLORIDE BASED DEEP EUTECTIC SOLVENTS VIA HYDROMETALLURGY METHOD

Abstract

The increasing demand for lithium in clean energy requires environmentally friendly methods to handle spent lithium-ion batteries (LIBs) at their end of life. The hydrometallurgical recycling process which depends on strong inorganic acids leads to major environmental damage. The research investigates DES-based hydrometallurgical methods for lithium extraction from spent LIBs. The research team optimized lithium recovery through experiments that tested different solid-to-liquid ratios and temperatures and times and H₂O₂ concentrations. The researchers achieved a 91.6% lithium extraction rate through their experiments which used 80°C temperature and 4 hours of reaction time and 2 vol% H₂O₂ concentration. The process maintained cobalt dissolution at 25% during standard operations while showing strong lithium selectivity but the low-oxidant method resulted in less than 5% cobalt extraction at reduced lithium production. The DES maintained its efficiency above 84% after undergoing five consecutive cycles which proved its excellent reusability potential. The DES maintains its stability while it breaks down LiCoO₂ through complexation-based dissolution according to FTIR and XRD and SEM results. The research team successfully obtained lithium carbonate (Li₂CO₃) from lithium extraction through a process that produces a useful material for battery manufacturing. The research demonstrates that choline chloride DES functions as an environmentally friendly lixiviant which achieves effective lithium extraction while supporting battery component circular economy practices.