▎ 摘　　要

Supercapacitors are new generation efficient energy storage devices having applications in diverse fields ranging from miniaturized wearable electronics to electric vehicles. Nanocarbonaceous materials like two-dimensional graphene (single sheet of graphite) and one-dimensional tubular carbon nanotubes (seamless cylinder made from graphene sheet) are highly preferred for making supercapacitor electrodes owing to their superior physiochemical properties. Herein, we have reported a facile method to prepare a nanohybrid of reduced graphene oxide (rGO)/multi-walled carbon nanotubes (MWCNTs) to exploit the properties of both nanocarbons through a single nanohybrid. During the formation of the nanohybrid, carbon nanotubes sit in between graphene sheets and in turn enhance the available surface area for interactions with electrolyte ions. Nanohybrids of carbon nanotubes and graphene with varied content of carbon nanotubes (1wt%, 5wt%, 10wt%, 15wt%, 20wt%) in graphene were prepared, and their supercapacitive performances were carefully examined. The nanohybrids were reduced through non-hazardous microwave treatment method. Nanohybrids were characterized by field emission scanning electron microscopy, UV-visible spectroscopy, Fourier transformed infrared spectroscopy and X-ray diffraction techniques. Electrochemical supercapacitive characterization of the nanohybrid with rGO/15wt% MWCNTs displayed maximum specific capacitance of 524.40 F/g at a scan rate of 2 mV/s. The rGO/MWCNT nanohybrid showed very good Coulombic efficiency and high stability even after 2000 cycles. Maximum energy density of the nanohybrid-based electrode was calculated to be 42.64 Wh/kg at power density of 651.35 W/ kg.