Singapore Glass uses orange peel instead of hydrochloric acid, which reduces waste lithium batteries and is quite environmentally friendly!
Disposable disposable batteries are rarely used nowadays, accounting for about 20% of the overall market. Now all kinds of 3C products (short for three types of electronic products: computers, communications and consumer electronics) almost all use rechargeable lithium batteries, which are more environmentally friendly than disposable batteries and can be reused. At present, about 80% of the overall market is rechargeable batteries, which are an indispensable source of electricity for daily life and technological development.
However, lithium batteries have a day when their performance is exhausted. During the subsequent resource regeneration and the recovery of precious metals in the battery, secondary pollution may occur. Regarding the problem of heavy metal recycling, Singaporean scientists use 'orange peels' to recycle 90% of the precious metals in batteries, with minimal waste generated in the process.
On August 26 this year, a new study published by the Nanyang Technological University team in Singapore showed that about 90% of lithium can be extracted from waste lithium-ion batteries using orange peel , Cobalt, nickel and manganese. Scientists grind the dried orange peel into a powder and mix it with citric acid to replace acid and hydrogen peroxide. The results of the experiment show that this is the same as usual, and a large amount of precious metals can be extracted from discarded lithium-ion batteries. When scientists use orange peel, they found that the residue is non-toxic, this method does not produce any pollutants, and the protection of the environment can be improved.
Every year, approximately 1.3 billion tons of food waste and 50 million tons of electronic waste are generated globally. This experiment turned waste into resources, effectively disposing of food waste and electronic waste. In the past, to remake waste lithium batteries, it was necessary to melt precious metals at temperatures above 500°C. This practice consumes energy and produces toxic gases. Although the battery has been ground, the heating process and the addition of acid and hydrogen peroxide will still bring a lot of pollutants to the earth.
Dalton Tay, an assistant professor in the School of Materials Science and Engineering and School of Biological Sciences at NTU, said that the key principle of the above method is that the cellulose in the orange peel will be heated during the extraction process. It is converted into sugar, and the natural antioxidants in sugar and orange peel can increase the metal recovery rate. The natural antioxidants contained in orange peels (such as flavonoids and phenolic acids) help refine it. In addition, Madhavi Srinivasan, co-director of the NTU Circular Economy Research Consortium (SCARCE) Laboratory, also said that the current recycling methods of e-waste are very energy-intensive and also emit various harmful pollutants. This research and development supports the development of a zero-waste circular economy, not only can use precious metal recycling to alleviate the scarcity of resources, but also solve the problem of waste recycling and food waste.
Currently, researchers are remaking the recycled metal into batteries. The battery capacity is equivalent to that of the commercially available models, but further tests are needed to see if the new batteries can be used. Continue a considerable number of charge and discharge cycles. This research was supported by the National Research Foundation, the Ministry of Development and the National Environment Agency, which is part of the 'Close Waste Recycling' research and development program and is part of the Urban Solutions and Sustainable Development Integration Fund. The research results were published in the July scientific journal 'Environmental Science and Technology'.