Graphene for ultracapacitors

Graphene, the basic building block of all graphitic materials has received significant scientific interest due to its ultra-high surface area (>2,630 m 2 /g), high charge carrier mobility, high thermal conductivity, etc. In particular, graphenes high surface area and excellent electrical conductivity has made it a leading candidate for next generation electrode material in energy storage devices such as ultracapacitors. One of the approaches for high volume production of graphene is the reduction of exfoliated graphite oxide (GO) sheets by thermal annealing, and/or reducing agents. However, the high temperature annealing process consumes a large amount of energy. Furthermore, large quantities of toxic reducing agents such as hydrazine and dimethylhydrazine are required. In this paper microwave (MW) assisted heating is studied as a scalable approach for the synthesis of reduced graphene. In this study, dry MW irradiation (MWI) synthesis of the reduced graphene is successfully demonstrated and the MW reduced GO shows a improved electrode performance when compared to highly porous activated carbon; the state of the art electrode material in commercial ultracapacitors.