Simple and Cost-Effective Synthesis of Activated Carbon Anchored by Functionalized Multiwalled Carbon Nanotubes for High-Performance Supercapacitor Electrodes with High Energy Density and Power Density

We prepared a composite using activated carbon and functionalised multiwalled carbon nanotubes by a simple and cost-effective process and investigated its use for supercapacitor application. The electrochemical performance of the prepared composite has been investigated by galvanostatic charge-discharge (GCD) and cyclic voltammetry (CV) measurements in a three-electrode set-up. The composite resulted in maximum specific capacitance of 395 F/g at 5 mV/s as measured by CV, and of 372 F/g at 60 A/g by GCD measurement in 3M KOH aqueous electrolyte. High power and energy density of 75.27 kW/kg and 25.31 W center dot h/kg at 60 A/g have been respectively obtained for composite using GCD measurement. The long-term charge-discharge stability has been performed for the composite electrodes, and it is observed that 89% of capacitance is retained even after 5000 cycles. The achieved results suggest that the prepared activated carbon/multiwalled carbon nanotube composite can be a potential electrode material in high-performance supercapacitors for energy storage applications. Graphic abstract