By Juan J. Alcolado
Scientists in South Korea have developed a new way of storing energy that also offers a solution to a growing environmental problem.
Reports on their findings have been published in the journal IOP Publishing Nanotechnology, reporting on the research team's success in turning used cigarette butts into a high-performance material that can be integrated into computers, portable devices, electric vehicles and renewable facilities for store energy.
According to the study, this material outperforms commercially available carbon, graphene and carbon nanotubes.
It is possible to use it to coat the electrodes in electrochemical supercapacitors: components that can store very large amounts of electrical energy.
"Our study has shown that cigarette filters can be transformed into a high-performance carbon-based material through a simple one-step process, while offering a green solution to meet society's energy demands." said co-author Professor Jongheop Yi of Seoul National University.
"Many countries are developing strict regulations to avoid the trillions of toxic and non-biodegradable used cigarette filters that are not disposed of from the environment each year. Our method is just one way to achieve this," adds Professor Yi.
Carbon is the most common material found in supercapacitors due to its low cost, high electrical conductivity, and long-term stability.
Scientists around the world are working to improve the characteristics of supercapacitors - such as their stability, energy density, power density and cycle - trying to reduce production costs.
In their study, Professor Yi and his colleagues showed that the cellulose acetate fibers present in most cigarette filters could be transformed into a carbon-based material using a simple, one-step recording technique called pyrolysis.
The resulting material will contain a series of small pores, which increases its performance as a supercapacitive material. "A high-performance supercapacitor material must have a large surface area, which can be achieved by incorporating a large number of small pores into the material," says Professor Yi.
"A combination of different pore sizes ensures that the material has high power densities, which is an essential property in a supercapacitor." Once manufactured, the carbon-based material is attached to an electrode and tested in a three-electrode system to observe the behavior of the material in absorbing electrolyte ions (charging) and then releasing them (discharge).
The material manages to store more electrical energy than graphene and carbon nanotubes available on the market. "Our carbon-based material has the potential to be used as an electrode material in lithium-ion batteries, as well as a support catalyst in fuel cells and pollutant adsorbents," says Professor Yi.
"We hope that our inventions will help reduce the environmental burden of cigarette butts while reducing the cost of manufacturing high-quality carbon materials."