Fast Activation of Graphene with Corrugated Surface and its Role in Improved Aqueous Electrochemical Capacitors

In graphene based materials, the energy storage capacity is usually improved by rich porous structures with extremely high surface area. By utilizing surface corrugations, this work shows an alternative strategy to activate graphene materials for large capacitance. We demonstrate how to simply fabricate such activated graphene and how these surface structures helped to realize considerable specific capacitance (e.g., electrode capacitance of ~340 F g-1 at 5 mV s-1 and device capacitance of ~ 343 F g-1 at 1.7 A g-1) and power performance (e.g., power density of 50 and 2500 W kg-1 at the energy density of ~10.7 and 1.53 Wh kg-1, respectively) in aqueous system, which are comparable to and even better than those of highly activated graphene materials with ultra-high surface area. This work demonstrates a new path to enhance the capacity of carbon-based materials, which could be developed and combined with other systems for various improved energy storage applications.