Orange Peel Helps to Recycle Precious Metals from Lithium-Ion Batteries

Orange peel helps to recycle lithium-ion batteries. Scientists led by Nanyang Technological University, Singapore (NTU Singapore) have developed a novel method of using fruit peel waste to extract and reuse precious metals from spent lithium-ion batteries in order to create new batteries. The scientists say that their waste-to-resource approach tackles both food waste and electronics waste, supporting the development of a circular economy with zero waste.

The local universities have successfully used fruit peels to extract and recycle precious metals from exhausted lithium batteries, turning waste into treasures and making new batteries. The team demonstrated their concept using orange peel, which recovered precious metals from battery waste efficiently. They then made functional batteries from these recovered metals, creating minimal waste in the process.

At present, to extract precious metals from waste lithium batteries, a high temperature of over 500 degrees Celsius is generally used to dissolve the battery, and toxic gases will be released in the process. Other methods, such as using strong acid solutions or weak acid liquids containing hydrogen peroxide to decompose metals, will still release secondary pollutants that can pose health and safety risks.

The research carried out by the CEA Circular Economy Research Center, affiliated to Nanyang Technological University's Energy Research Institute, found that the addition of citric acid in citrus fruits can achieve the same effect after orange peel is dried and ground into powder.

The NTU research team successfully used the above method to extract nearly 90% of cobalt, lithium, nickel, and manganese from spent lithium-ion batteries in the experiment. The effect is equivalent to the use of hydrogen peroxide.

Assistant Professor Zheng Zuyang at NTU explained that the cellulose contained in orange peels is heated and converted into sugar. The sugar helps to recycle metals in waste batteries. "The natural antioxidants in fruit peel, such as flavonoids and phenolic acids, can also enhance the recovery effect." Zheng pointed out that the solid residues produced in this process are non-toxic, indicating that this method is environmentally friendly.

Researchers use recycled metal to make new lithium batteries with a charge capacity similar to those on the market. The research team will then improve the performance of the battery, optimize the recycling process to expand the scale of production, and study whether to use acidic substances.

From the current research results, the research team believes that this method of recycling lithium batteries can be used in industry.

Professor Madhavi Srinivasan at NTU's School of Materials Science and Engineering pointed out that the approach of using orange peel to recycle precious metals from lithium-ion batteries could also potentially be extended to other types of cellulose-rich fruit and vegetable waste, as well as lithium-ion battery types such as lithium iron phosphate and lithium nickel manganese cobalt oxide. This would help to make great strides towards the new circular economy of e-waste, and power our lives in a greener and more sustainable manner.

• < Prev
• Next >