Reduced Graphene Oxide as a Monolithic Multifunctional Conductive Binder for Activated Carbon Supercapacitors.

Using reduced graphene oxide (r-GO) as a multifunctional conductive binder, a simple, cost-effective, and environmentally friendly approach is developed to fabricate activated carbon/reduced graphene oxide (AC/r-GO) composite electrodes for supercapacitors with outstanding performance. In such a composite, r-GO provides several much needed critical functions: r-GO not only serves as the binder material improving the AC particle/particle cohesion and electrode-film/substrate adhesion but also improves the electrical conductivity of the composite and provides additional surfaces for ion adsorption. Furthermore, during electrode fabrication, initial GO precursor functions as an effective dispersant for AC, resulting in a stable electrode material slurry. Employing characterization by advanced microscopy techniques, we show that AC and r-GO assemble into an interconnected network structure, resulting in a composite with high specific capacitance, excellent rate capability, and long cycling life stability. Such high-performance electrodes coupled with their relatively simple, scalable, and low-cost fabrication process thereby provide a clear pathway toward large-scale implementation of supercapacitors.