Energy storage could be a good use for the estimated 5.6 trillion cigarette butts discarded annually.
One of the most commonly littered items; cigarette butts are mostly made from polymer acetate. Each butt contains thousands of fibers that can take more than a decade to break down.
They aren’t just unsightly – cigarette butts are toxic. The payload of poisons they contain; some of them carcinogenic, can also leach into the surrounding soil. A 2008 study found similar patterns of poly-aromatic hydrocarbons in roadside soil as in cigarette butts found in the same area. Cigarette butts can also be concentrated sources of heavy metals such as cadmium, arsenic and lead.
A group of scientists from South Korea have demonstrated that the cellulose acetate based filters can be transformed into a carbon-based material suitable for energy storage applications using a simple, one-step burning technique called pyrolysis. Pyrolysis is the thermochemical decomposition of organic material at elevated temperatures in the absence of oxygen.
The resulting material features tiny pores, increasing its performance for use as a coating for electrodes in supercapacitors.
Tests on the material have found it not only stores a higher amount of electrical energy than commercially available carbon; but also more than graphene and carbon nanotubes.
“Numerous countries are developing strict regulations to avoid the trillions of toxic and non-biodegradable used cigarette filters that are disposed of into the environment each year; our method is just one way of achieving this,” said co-author of a related study; Professor Jongheop Yi, from Seoul National University.
The researchers says the material was capable of reproducing its electrochemical performance during the 6000 cycles required for charge and discharge measurements.
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Trivia – according to ButtFree.org.au; 20 million cigarette butts are littered every day around Australia – more than 7 billion a year.
