Fermentation-Derived Active Lixiviants from Heterogeneous Fruit Waste for Sustainable Hydrometallurgical Recycling of Lithium-Ion Batteries

Abstract Lithium-ion battery (LIB) recycling plays a key role in reducing global e-waste production, and hydrometallurgy is the current technology of choice due to its efficiency and reliability. Most hydrometallurgy processes use inorganic acids that are corrosive in nature, and this has redirected new technologies to switch to using organic acid as the leaching agent. However, the cost of organic acids is generally high. Here, a greener and cost-effective alternative for hydrometallurgy is proposed through the fermentation of discarded mixed fruit peel waste, unsorted from one another, to produce organic acids. Different batches of mixed fruit peel lixiviants were first characterized before their efficiency in the hydrometallurgical leaching of lithium nickel manganese cobalt oxide (NMC) black mass was determined. Overall, the different mixed fruit peel lixiviants can achieve more than 80% recovery of valuable metals such as Li, Co, Mn, and Ni, with optimum performance arising from lixiviants with pH less than 3.5. Screening-level techno-economic analysis and process-level environmental performance screening were also discussed at the end to provide beneficial insights in the scaling up of this mixed fruit peel hydrometallurgy technique for real-life practical applications.