Three-dimensional ordered nanostructures for supercapacitor electrode

A novel three-dimensional (3D) network structure consisting of vertically aligned polyaniline array/graphene-film/polyaniline array was fabricated via multistep nanowire growth and graphene deposition. The choice of acid in the synthesis process plays a critical role in the morphology of 3D network structures and electrochemical performance. Using HClO4 helps to achieve more favorable porous morphology and led to better electrochemical properties. The 3D-network materials were used as supercapacitor electrode, and the electrochemical impedance results indicated that the charge transfer resistance was as low as ignorable. The ion diffusion resistance could be as low as 0.22 Omega due to the novel well-defined three-dimensional network structure. Ragone plots showed that this novel structure contributed to high power-density and energy-density. The optimal supercapacitor demonstrated a combination of high power-density (7622 W kg(-1)) and energy-density (126 Wh kg(-1)). (C) 2013 Elsevier Ltd. All rights reserved.