Graphene-Wrapped Polyaniline Hollow Spheres As Novel\nHybrid Electrode Materials for Supercapacitor Applications

Abstract

Polyaniline\nhollow spheres (PANI-HS)@electrochemical reduced graphene oxide (ERGO)\nhybrids with core–shell structures have been fabricated <i>via</i> a solution-based coassembly process. The hollow nanostructured\ndesigning for the PANI-HS greatly enlarges the specific surface area,\nproviding high electroactive regions and short diffusion lengths for\nboth charge and ion transport. The wrapping of ERGO sheets on the\nPANI-HS can offer highly conductive pathways by bridging individual\nPANI-HS together, thus facilitating the rate and cycling performance\nof supercapacitors. The specific capacitance of PANI-HS36@ERGO hybrids\ncan reach 614 F g^–1 at a current density of 1 A\ng^–1. Furthermore, the capacitance of the PANI-HS36@ERGO\nhybrids maintains 90% after 500 charging/discharging cycles at a current\ndensity of 1 A g^–1, indicating a good cycling stability.\nThe greatly enhanced electrochemical performance can be ascribed to\nthe synergic effects of the two components of PANI-HS and ERGO, suggesting\nthat the PANI-HS@ERGO hybrids as novel electrode materials may have\npotential applications in high-performance energy storage devices.