Physical Chemistry Chemical Physics 2011-06-21

High-performance supercapacitor electrodes based on graphene hydrogels modified with 2-aminoanthraquinone moieties.

Qiong Wu, Yiqing Sun, Hua Bai, Gaoquan Shi

Index: Phys. Chem. Chem. Phys. 13(23) , 11193-8, (2011)

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Abstract

2-Aminoanthraquinone (AAQ) molecules were covalently grafted onto chemically modified graphene (CMG), and the AAQ functionalized CMG sheets were self-assembled into macroporous hydrogels for supercapacitor electrodes. The electrode based on the AAQ modified self-assembled graphene hydrogel (AQSGH) showed a high specific capacitance of 258 F g(-1) at a discharge current density of 0.3 A g(-1), which is much larger than that of a pure graphene hydrogel (193 F g(-1)). Furthermore, the AQSGH electrode exhibited excellent rate capability and a long cycle life. This is mainly due to the covalently bonded AAQ moieties contributing additional redox capacitance. Furthermore, the highly conductive graphene hydrogel scaffold provided a large specific surface area for forming electric double layers and convenient routes for charge transfer and electrolyte diffusion.