Following a successful proof-of-concept to recycle spent lithium-ion batteries (LIBs) using reagent extracted from fruit peel waste, Nanyang Technological University, Singapore (NTU; www.ntu.edu.sg) has partnered with Se-cure Waste Management Pte. Ltd. (SWM; Singapore; www.se-curewaste.com) to scale up the technology in a pilot plant. The pilot plant, which has been operational since late 2022, has the capacity to process up to 2,000 L of shredded LIBs.
Over the course of this year, the NTU and SWM team will work to optimize processes that maximize the extraction yield of valuable metals. They will also evaluate the plant’s technical performance and economic viability with the goal of commercializing the technology.
In 2020, an NTU team successfully extracted over 90 wt.% of the metals found in processed LIB waste in the laboratory using orange peel waste and made new batteries with these recovered metals (Chem. Eng., October 2020, p. 6). The process, which uses fruit peel waste instead of conventional strong chemicals and acids to extract metals from battery waste is called hydro-organic-metallurgy. Since then, the scientists have successfully replicated their laboratory results using other types of fruit peel waste (pineapples, pears and lemons).
On average, SWM processes 18 metric tons (m.t.) of spent LIBs every day. The company first shreds and crushes spent LIBs and then separates out plastics and some metals, such as Cu, Al and Fe. The final product, called black mass, contains the metals to be extracted for reuse (Co, Li, Ni and Mn). This black mass is fed to the pilot plant, where it is dissolved in chemicals derived from fruit peel wastes. These chemicals, for which the scientists have filed a patent, leach out metals at relatively low temperatures. The leached metals are then precipitated as salts that can then be used for making new LIBs.