scientists from South Korea have converted cigarette butts into a high-performing material that could be used to coat the electrodes of supercapacitors [1].

The material is produces via the heat treatment of used cigarette butts in a nitrogen rich environment.

The article states that the processed cigarette filter material stored a higher amount of electrical energy than commercially available carbon. Also the material stored more energy than the more experimental materials graphene and carbon nanotubes.

If the process can be made economically viable then this process could be used to ecologically recycle cigarette butts.

Reference
[1] Minzae Lee, Gil-Pyo Kim, Hyeon Don Song, Soomin Park and Jongheop Yi, Preparation of energy storage material derived from a used cigarette filter for a supercapacitor electrode, 2014 Nanotechnology 25 345601.

Link
Cigarette butts offer energy storage solution IOP News