Pseudocapacitive organic catechol derivative-functionalized three-dimensional graphene aerogel hybrid electrodes for high-performance supercapacitors

Bio-inspired and environmentally friendly chemical functionalization is a successful way to a new class of hybrid electrode materials for applications in energy storage. Quinone (Q)-hydroquinone (QH(2)) couples, a prototypical example of organic redox systems, provide fast and reversible proton-coupled electrontransfer reactions which lead to increased capacity. To achieve high capacitance and rate performance, constructing three-dimensional (3D) continuous porous structure is highly desirable. Here we report the hybrid electrodes (GA-C) consisting of 3D graphene aerogel (GA) functionalized with organic redox-active material, catechol derivative, for application to high-performance supercapacitors. The catechol derivative is adsorbed on the surface of GA through non-covalent interactions and promotes fast and reversible Q/QH(2) faradaic reactions, providing large specific capacitance of 188 Fg(-1) at a current of 1 Ag-1 and a specific energy of similar to 25 Wh kg(-1) at a specific power of similar to 18,000 W kg(-1). 3D continuous porous structure of GA electrode facilitates ion and electron transports, resulting in high rate performance (similar to 40 Fg(-1) at a current of 10 A g(-1)). (C) 2017 Elsevier B.V. All rights reserved.