RESUMO
A hierarchical carbon nanotube-polypyrrole (CNT-PPy) core-shell composite was fabricated by growing CNTs directly on carbon cloth (CC) as a skeleton followed by electropolymerization of PPy with controlled polymerization time. Direct fabrication of electroactive (CNT-PPy) materials on the flexible CC electrode could reduce the interfacial resistance between the electrode and electrolyte and improve the ion diffusion. The supercapacitor electrode based on optimized PPy/CNT-CC exhibits excellent electrochemical performance, with the highest gravimetric capacitance being roughly 1038â F g(-1) per active mass of PPy and up to 486.1â F g(-1) per active mass of the PPy/CNT composite. Notably, excellent flexibility and cycle stability up to 10 000â cycles with only 18 % capacitance loss was achieved. At the same time, the fabricated asymmetric supercapacitor (PPy/CNT-CCâ¥CNT-CC) shows the maximum power density of 10 962â W kg(-1) at an energy density of 3.9â Wh kg(-1) under the operating potential of 1.4â V. The overall high cycle stability and high performance of the fabricated PPy/CNT-CC flexible electrode is due to the novel binder-free direct growth process.