High-yield synthesis of carbon nanotube-porous nickel oxide nanosheet hybrid and its electrochemical capacitance performance

This study reports an easy chemical conversion route toward large-scale fabrication of carbon nanotube (CNT)-porous nickel oxide (NiO) hybrid nanocomposites as supercapacitor electrode materials. The electrocapacitive performance of CNT-porous NiO hybrids is evaluated by cyclic voltammetry and galvanostatic charge-discharge measurements. The synthesized CNT-NiO hybrid nanocomposite electrode presents a high specific capacitance of 759 F g−1 at 0.5 A g−1 in 6 M KOH aqueous electrolyte, which is almost twice that of pure NiO nanoparticle (388 F g−1) electrodes and nine times of that of commercial NiO particle (88.4 F g−1) electrodes. Furthermore, good capacitance retention is achieved after 1000 cycles of galvanostatic charge-discharge. The synergistic effects from the pseudocapacitance of porous NiO particles, good electrical conductivity, and open tip CNTs attribute to the high capacitance performance.