Reduced graphene oxide/polyaniline electrochemical supercapacitors fabricated by laser

We report on the precise fabrication of low-cost high-performance electrochemical supercapacitors using reduced graphene oxide/polyaniline nanofiber composite electrodes. An infrared laser has been used to reduce the graphene oxide, converting the initial graphene oxide compact layer into a three dimensional open network of exfoliated graphene flakes. This highly conducting porous structure is very well suited for electrodepositing pseudocapacitive materials owing to its large surface area. Polyaniline nanofibers have been controllably electrodeposited on the graphene flake network, not only extending further the electrode surface area and providing it with a strong pseudocapacitance but also preventing the restacking of the graphene sheets during the subsequent device processing and charge-discharge cycling. The composite electrode presents a specific capacitance of 442 F g(-1), as compared to 81 F g(-1) for the bare reduced graphene oxide counterpart, and a capacitance retention of 84% over 2000 cycles.