COMPOSITE FILMS PREPARED BY DEPOSITION OFMANGANESE DIOXIDE AND POLYPYRROLE ON IN-SITUGROWN CARBON NANOTUBES FOR SUPERCAPACITORS

摘要

Carbon nanotube/manganese dioxide (CNT/MnO_2) composite films on graphite current collectorwere prepared by immersing the CNT films, which were grown on the substrate by chemicalvapor deposition, into a potassium permanganate solution. The reduction of the permanganateallowed the oxide to be deposited in the CNT films, even for the densely packed aligned CNTs.Deposition of the oxide benefited increasing specific capacitance. For the in-situ grown CNTs,their conducting substrate provided a condition for performing electropolymerization fordepositing polypyrrole (PPy) on the porous CNT films. While the CNT/PPy composite hadlarger specific capacitance than the CNTs, they gave better rate performance and cyclic behaviorthan the polymer. Using the in-situ grown CNTs could potentially be a convenient approach forstudying deposition of pseudo-capacitive materials for developing high performancesupercapacitors.