According to a study recently published in the journal Nanotechnology, cigarette filters could be nothing less than the long-awaited solution to the renewable energy storage conundrum. That’s right: the source of pollution could eventually become a cornerstone of the bioeconomy.
‘Our study has shown that used-cigarette filters can be transformed into a high-performing carbon-based material using a simple one step process, which simultaneously offers a green solution to meeting the energy demands of society,’ explains Jongheop Yi, Professor at the Seoul National University and co-author of the study.
But what’s so great about cigarette filters exactly? The answer lies in two words: cellulose acetate. This component, which is used in 95% of cigarette filters, is favoured by the industry for the taste it produces. Incidentally, this same material can be turned into a supercapacitor with excellent energy density, power density and cycle stability properties. The team was able to do that with a one-step burning technique called pyrolysis.
‘A combination of different pore sizes ensures that the material has high power densities, which is an essential property in a supercapacitor for the fast charging and discharging,’ says Prof. Yi. Carbon is the most popular material that supercapacitors are composed of due to its low cost, high surface area, high electrical conductivity and long term stability.
Testing showed that the material can store a higher amount of electrical energy than commercially available carbon and also has a higher amount of storage compared to 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,’ notes Prof. Yi.
The new material could soon be integrated into computers, handheld devices, electrical vehicles and wind turbines to store energy. But what’s so attractive about it is the solution it provides for tackling a very important source of pollution, which notably releases arsenic and other harmful chemicals into the earth and waterways. Some 5.6 trillion – or 766,571 metric tons – of used-cigarettes are littered into the environment every year, worldwide.