MnO_2 nanowires electrodeposited on freestanding graphenated carbon nanotubes as binder-free electrodes with enhanced supercapacitor performance

摘要

MnO2 nanowires/graphenated carbon nanotubes (CNTs) have been fabricated on stainless steel (SS) substrate through chemical vaporous deposition (CVD) and electrodeposition method as binder-free super-capacitor electrodes. The MnO2 nanowires/graphenated CNTs nanocomposites have high areal capacitance of 492.5 mF/cm(2) (615.6 F/g) at the current density of 0.5 mA/cm(2) and outstanding energy density of 985 Wh/m(2) with power density of 2.98 kW/m(2). After 5000 cycles at 0.5 mA/cm(2), the capacity retention of the MnO2/graphenated CNTs is still maintained 95% of the initial capacitance, suggesting exceptional capacitance retention and superior stability. The predominant electrochemical performance of the MnO2/graphenated CNTs is contributed to the synergistic effects of high conductivity of graphenated CNTs and high pseudocapacitance of MnO2 nanowires. (C) 2019 Published by Elsevier B.V.