Singapore has launched an innovative pilot plant that leverages discarded fruit peels to recover valuable metals from spent lithium-ion batteries. This initiative, a collaboration between Nanyang Technological University (NTU) researchers and local recycling firm Se-cure Waste Management, promises a greener approach to managing electronic waste.
Addressing Dual Waste Challenges
Operational since late 2022, the facility near Neythal Road can process up to 2,000 litres of shredded battery waste at once. The project tackles two critical global issues simultaneously: the rapidly growing volume of electronic waste and discarded food. Currently, less than 5% of used lithium-ion batteries are recycled worldwide, with projections indicating 11 million tonnes of spent batteries by 2030.
The "Hydro-Organic-Metallurgy" Process
The recycling process begins by shredding and crushing used batteries, then separating plastics and metals like copper, aluminum, and iron. What remains is a "black mass," a material rich in electrode metals such as cobalt, lithium, nickel, and manganese. This black mass is subsequently treated with specialized solvents derived directly from fruit peel waste.
NTU researchers have termed this method "hydro-organic-metallurgy." The natural sugars, organic acids, flavonoids, and phenolic acids present in the fruit peels effectively dissolve and facilitate the recovery of these valuable metals from the battery waste. The recovered materials are then transformed into metal salts, which hold the potential to be re-integrated into the manufacturing of new lithium-ion batteries, creating a circular economy.
Promising Results and Future Prospects
Initial laboratory experiments conducted by the NTU team in 2020 demonstrated impressive results, recovering over 90% by weight of valuable metals from processed battery waste using orange peels. Batteries subsequently manufactured with these recovered metals exhibited charge capacities comparable to commercial batteries. The researchers successfully replicated this efficient process using other biomass sources, including lemon and pineapple peels.
"The proposed innovation provides an immediate and scalable solution to reduce both food waste and electronic waste," stated Associate Professor Dalton Tay. He further emphasized, "The recovered metal salts can then be reused to generate new batteries, and by so doing, we're able to close the waste loop while offering a sustainable cradle-to-cradle solution."
The current pilot project is focused on refining metal-recovery yields and comprehensively evaluating both its technical performance and economic viability. If successful, this innovative, fruit-peel-based method could offer a significantly less hazardous alternative to conventional battery recycling techniques, which often rely on strong corrosive chemicals or high-temperature processes.