Energy-Storing Cigarette Butts

More than five trillion used cigarette butts end up in the environment every year. But researchers recently found a way to transform an environmental problem into an eco-friendly energy solution by turning the filter material into a high-performance coating for supercapacitors that boosts their capacity to store large amounts of energy.

In the quest to improve the characteristics of supercapacitors, increased power density is an important property for speeding up charge-discharge cycles. That means the supercapacitor material must have a large surface area with a combination of different sized pores to adsorb and release electrolyte ions.

The researchers found that using a simple burning technique (called pyrolysis), the cellulose acetate fibers in the cigarette filters could be transformed into a carbon-based material with a number of tiny pores. The result is a material that performs better than graphene or carbon nanotubes currently used to coat the electrodes of supercapacitors, and is less expensive to produce. The coating could be used in everything from computers and mobile devices to electric vehicles and wind turbines to meet the growing demand for more efficient energy storage.