High-performance porous electrodes for pseudosupercapacitors based on graphene-beaded carbon nanofibers surface-coated with nanostructured conducting polymers

摘要

This paper reports the fabrication and electrochemical properties of novel high-performance pseudo-supercapacitor electrodes made of graphene-beaded carbon nanofibers (G/CNFs) surface-coated with nanostructured conducting polymers. The G/CNFs were produced by electrospinning the precursor graphene-beaded polymer nanofibers, followed by controlled pyrolysis. In situ polymerization in aqueous solution was utilized to coat an ultrathin layer of thorn-like polyaniline (PANI) nanorods onto the G/CNFs to form ternary PANI-coated G/CNFs (PANI-G/CNFs). The highly porous network morphology of PANI-G/ CNFs exhibited a very large specific surface area, low internal resistance, and fast redox rate. Electrochemical characterization indicated that the PANI-G/CNF based pseudosupercapacitors carried a high value of specific capacitance up to 637 F g~(-1) at a current density of 0.15 A g~(-1) and still maintained the high value of specific capacitance of 478 F g~(-1) (only 25% decrease) even at a high current density of 6 A g ~(-1). The pseudosupercapacitor showed a very good cycling stability of 87% after 1000 charge/discharge cycles at a very high current density of 15 A g~(-1). The experimental results indicated that the novel hierarchical, porous PANI-G/CNFs are a promising electrode material for use in high-performance energy storage devices.