A team of researchers at Singapore's Nanyang Technological University (NTU) has unveiled a promising new approach to recycling used lithium-ion batteries, and the secret ingredient comes straight from the kitchen: discarded citrus and pineapple peels. The findings, which were presented at a pilot recycling facility in Singapore, suggest that fruit waste rich in citric acid could replace harsh chemicals currently used in battery recycling processes.
Lithium-ion batteries power everything from smartphones and laptops to electric vehicles, and as adoption of these technologies accelerates globally, so does the volume of spent batteries heading to landfills. Traditional recycling methods rely on high-temperature smelting or strong acids such as hydrochloric and sulfuric acid — processes that are energy-intensive, environmentally damaging, and costly. The NTU team's workaround uses citric acid, a naturally occurring compound abundant in oranges, lemons, and pineapples, to dissolve and extract key metals like lithium, cobalt, and nickel from spent battery material.
In laboratory trials, the researchers reported that the citric acid solution was able to recover over 95% of the valuable metals from crushed battery electrodes — a recovery rate comparable to conventional methods but achieved under milder conditions and with far less environmental harm. The extracted metals can then be fed back into the manufacturing supply chain to produce new lithium-ion batteries, effectively closing the loop in what experts call a circular economy for battery materials.
The process works by first crushing the used batteries and soaking the resulting powder in a citric acid solution. The acid reacts with the metal compounds in the battery sludge, dissolving them into the liquid. The solution is then further processed through precipitation and other separation techniques to isolate individual metals in pure form. Because citric acid is biodegradable and far less corrosive than the mineral acids typically used, the entire operation poses fewer safety risks and generates less toxic wastewater.
NTU researchers emphasized that while the technique has shown strong results in the lab and at pilot scale, it still needs to be tested in larger industrial operations before it can be commercially deployed. The university's team is now working on optimizing the concentration of citric acid, the duration of the soaking process, and ways to scale up production efficiently. Industry partners have expressed interest in partnering on full-scale trials.
Battery recycling has become a critical issue worldwide. According to the International Energy Agency, the number of end-of-life EV batteries is expected to surge dramatically over the next decade as the first major wave of electric vehicle batteries reaches the end of their useful life. Countries across Europe, China, and North America are investing billions in domestic recycling infrastructure, and innovations like the NTU fruit-peel method could offer a more sustainable alternative to existing approaches — particularly for developing nations that lack the capital for expensive recycling plants.
Environmental groups have welcomed the research. Dr. Priya Menon, a battery-life-cycle specialist at the Centre for Sustainable Chemistry in Delhi, called the study "a genuinely exciting step toward greener e-waste management." She noted that replacing aggressive acids with food-grade citric acid could significantly reduce the carbon footprint of recycling facilities — though she cautioned that widespread adoption depends on whether the process can be made cost-competitive with established methods at industrial scale.
