This study demonstrates an asymmetric supercapacitor having SnO2-reduced graphene oxide (RGO) nanocomposite
as the cathode and nitrogen-doped graphene (NDG) as the anode. A facile method has been used to synthesize
the SnO2-RGO nanocomposite and NDG. Material characteristics were examined using X-ray
diffractometry, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy.
Electrochemical measurements, including cyclic voltammetry and electrochemical impedance spectroscopy,
were performed to evaluate the asymmetric supercapacitor. Optimized asymmetric supercapacitor
has been shown to operate under awideworking potentialwindowup to 1.8 V and exhibit a high energy density
of 48.7Wh kg−1, and excellent electrochemical stability in 2 M H2SO4 aqueous electrolyte.