As the world moves away from dirty, polluting energy sources like gas and oil and toward clean, renewable sources like solar and wind, there is one element of clean energy that still poses big environmental problems: the lithium-ion batteries in which clean energy is stored.
Now, a breakthrough from scientists at Nanyang Technological University, Singapore, may have led to the most environmentally friendly method of recycling these batteries yet. The new method uses fruit peels to extract precious metals from spent batteries, which can then be reused in new batteries.
By using fruit peels, the scientists say that they can help provide a solution for both food waste and electronics waste at the same time.
Other methods of recycling lithium-ion batteries involve extreme heat and chemicals that produce secondary pollutants, leading to health and safety risks.
“Current industrial recycling processes of e-waste are energy-intensive and emit harmful pollutants and liquid waste, pointing to an urgent need for eco-friendly methods as the amount of e-waste grows. Our team has demonstrated that it is possible to do so with biodegradable substances,” said Professor Madhavi Srinivasan, one of the researchers behind the discovery. “These findings build on our existing body of work.”
The NTU team was able to achieve the same results as industrial recycling processes using just orange peels and citric acid, a weak organic acid found in citrus fruits, with no extreme temperatures required.
The need to recycle more lithium-ion batteries is clear. The production of these batteries requires rare-earth metals like lithium, copper, and cobalt, the mining of which causes immense environmental degradation and excessive water use. While the sun and wind energy harvested and stored in these batteries are renewable resources, the materials needed to make them are not.
Other methods of recycling lithium-ion batteries have been developed or are currently being developed — these include “black mass” recycling, hydrometallurgical recycling, and more.