Polyaniline/graphene hybrid fibers as electrodes for flexible supercapacitors

Graphene fiber-based supercapacitors have attracted tremendous interest and possess the greatest potential for flexible/wearable energy storage devices. However, their specific capacitance and energy density are not sufficient and impede their widespread practical application. Here, polyaniline/graphene hybrid fibers (PANI/GF) were fabricated by a simple in situ chemical polymerization of polyaniline on graphene fibers synthesized by the wet-spinning method and a chemical reduction process. The crumpled morphology of the graphene fibers and polymerization process in a dilute solution of aniline monomer improve the structural uniformity and stability of the composite fibers. The hybrid fibers based flexible supercapacitor with solid-state electrolyte not only deliver high specific capacitance of 87.8 m F cm−2 and high energy density of 12.2 μW h cm−2 at a current density of 0.22 mA cm−2, but also exhibits long cycling stability after 10,000 cycles. This is mainly ascribed to the uniform dispersion of polyaniline on the graphene fibers and the stable structure of the hybrid fibers. The as-synthesized graphene hybrid fibers are a promising candidate for flexible/wearable supercapacitors.