title: Incorporation of MnO2-coated carbon nanotubes between graphene sheets as supercapacitor electrode.
abstract: Hierarchical graphene-based composite consisting of graphene sheets intercalated by MnO(2)-coated carbon nanotubes (MnC) was prepared for high-performance supercapacitor electrode. The highly negatively charged graphene oxides reduced by urea (RGO) and the positively charged MnC functionalized with poly(diallyldimethylammonium chloride) created a strong electrostatic interaction, forming a hierarchical nanostructure. The elelctrocapacitive behaviors of MnC/RGO (MnC-G) were systematically investigated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. A maximum specific capacitance of 193 F/g was achieved for the MnC-G composite with 37% RGO, which was almost 3-fold higher than 69 F/g of carbon nanotubes/RGO and 2-fold higher than 89 F/g of MnO(2)/RGO composite. Moreover, an excellent rate performance, a good capacitance retention (~70%) and a superior Coulombic efficiency (94-96%) were also observed during the continuous 1300 cycles of galvanostatic charge-discharge.
authors.affiliation: Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, 117576 Singapore.
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Lei
authors.forename: Fuhua
authors.initials: F
authors.lastname: Shi
authors.forename: Li
authors.initials: L
authors.lastname: Lu
mesh_terms: D025802:Electric Capacitance; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D017895:Manganese Compounds / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D014508:Urea / Q000737:chemistry
chemical_list: D017895:Manganese Compounds; D037742:Nanotubes, Carbon; D010087:Oxides; C027424:manganese oxide; D006108:Graphite; D014508:Urea