Microwave-assisted chemical-vapor-induced in situ polymerization of polyaniline nanofibers on graphite electrode for high-performance supercapacitor.

Polyaniline (PANI) nanofibers-coated graphite electrode is fabricated by microwave-assisted chemical vapor induced in situ polymerization in the presence of ammonium persulfate. The microstructure and electrochemical performance of the as-prepared nanofibers are investigated in detail. The obtained PANI nanofibers at the optimum volume ratio of 4% aniline, with some protuberances on the surface and the diameter from 50 to 100 nm, are coated onto the surface of graphite electrode. The PANI-coated graphite electrodes display the best electrochemical performance in 6 M H2SO4 electrolyte, including a large reversible capacity of 2136 F g(-1) at the current density of 1 A g(-1) and excellent rate capability. In particular, The PANI-coated graphite electrode exhibits a long cycle life by retaining 91% of the initial specific capacitance after 1000 cycles. More importantly, a symmetric supercapacitor was fabricated using PANI-coated graphite electrode, showing maximum energy density and power density of 24 Wh kg(-1) and 6000 W kg(-1), respectively.