▎ 摘　　要

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 a wide working potential window up to 1.8 V and exhibit a high energy density of 48.7 Wh kg(-1), and excellent electrochemical stability in 2 M H2SO4 aqueous electrolyte. (C) 2016 Elsevier B.V. All rights reserved.