Template synthesis of graphene/polyaniline hybrid hollow microspheres as electrode materials for high-performance supercapacitor

Abstract

Graphene/polyaniline hybrid hollow microspheres are prepared via combining layer-by-layer assembly technique with in situ chemical oxidative polymerization after etching the templates for high-performance supercapacitor application. The hollow structure is characterized by transmission electron microscopy indicating that the inner diameter of the hollow microspheres is about 2.0 µm. The electrochemical tests show that the specific capacitance of the graphene/polyaniline hybrid hollow microsphere electrode materials can reach about 633 F g−1 in a 1.0 M H2SO4 electrolyte. It is higher than that of polyaniline hollow microspheres (389 F g−1), pure polyaniline particles (152 F g−1), and graphene/sodium alginate hollow microspheres (16 F g−1). The high specific capacitance might be attributed to the unique hollow structure and the synergistic effect of the hybrid shell. Their unique structure provides an enhanced surface-to-volume ratio and reduced transport lengths for both mass and charge transport. Furthermore, graphene/polyaniline hybrid hollow microsphere electrode materials display good cycle stability with 92 % of its original specific capacitance after 1,000 cycles by continuous cyclic voltammetric scans at 80 mV s−1.