Graphene-containing materials for use in supercapacitors

• One-step and eco-friendly synthesize of SnO2-RGO nanocomposites
• Improved Csp of SnO2 nanoparticles by as much as 14 times by the adding of RGO
• SnO2-RGO//NDG supercapacitor having a high energy density of 48.7 Wh kg− 1 at 1.8 V
• SnO2-RGO//NDG supercapacitor exhibits a long term stability after 2000 cycles.

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.