Three-dimensional porous polyaniline/graphene-coated activated carbon fiber electrodes for supercapacitors†
We fabricated unique structured electrodes composed of three-dimensional porous active carbon fibers (ACFs) coated with polyaniline and few-layer graphene (PANI/FLG-coated ACFs), which demonstrated excellent capacity for application in supercapacitors. Ni networks served as the template for graphene grown by annealing the electrodeposited Ni clusters on the surface of ACFs. After chemical vapor deposition, FLG was synthesized on the Ni surface which was subsequently coated with PANI serving as capacitive materials and supporting layers for FLG in the construction of shell structures during Ni etching. The surface combined a pultruded structure and cavity network formed with the PANI/FLG coatings, where the holes on the cavity increased the electroactive surface area and facilitated penetration of the electrolyte into the cavity networks, as a result the capacity was enhanced. In this study, an average specific capacitance of 400.16 F g−1 and an energy density of 61.27 W h kg−1 at a charging current of 0.1 A g−1 over the PANI/FLG-coated ACFs electrodes were achieved.