Cobalt Oxide Nanoflakes on Single Walled Carbon Nanotube Thin Films for Supercapacitor Electrodes

Abstract

We demonstrate a simple and cost-effective approach for the fabrication of cobalt oxide (Co3O4) nanoflakes on single walled carbon nanotube (SWNT) thin films for supercapacitor electrodes. SWNT thin films are prepared by vacuum filtration and consecutive stamping method onto which cobalt hydroxide (Co(OH)2) nanoflakes are electrodeposited and annealed to obtain Co3O4. A gravimetric capacitance of 313.9F.g−1, corresponding to an areal specific capacitance of 70.5 mF.cm−2 is obtained from the fabricated electrodes at a scan rate of 1mV/s. A capacity retention of up to 80% following 3000 cycles is obtained for the fabricated nanocomposite electrodes, while morphological evolution of the electrodes was monitored through high resolution transmission microscopy during cycling. Co3O4 nanoflakes show excellent structural stability through cycling with promising capacity retention, suggesting the potential of Co3O4 nanoflakes on SWNT thin films as supercapacitor electrodes.