Graphene-wrapped polyaniline hollow spheres as novel hybrid electrode materials for supercapacitor applications.

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