Characterization of the Electrochemical Properties of Nitrogen- Doped Graphene

摘要

In recent years, graphene has attracted extensive attention in many fields. A nitrogen-doped graphenesheet was synthesized using a solid microwave-mediated method. An experimental electrode wasthereafter prepared using nitrogen-doped graphene sheets (NGS), and the physical and electrochemicalproperties of nitrogen-doped graphene sheets were studied. A three-electrode supercapacitor testsystem with the experimental electrode also serving as one of the electrodes was built to conductconstant current charge/discharge, cyclic voltammetry, life span, and impedance spectrum tests on theexperimental electrode. After 5000 cycles of charging/discharging at a current density of 0.5 A/g, thespecific capacitance of the experimental electrode was 208.17 F/g with corresponding capacitanceretention of 98.56%; when the current density was increased to 5 A/g, the specific capacitance of theexperimental electrode after 5000 cycles of charging/discharging dropped to 157.31 F/g, indicatingcapacitance retention of 75.57%. The effective series resistance was approximately 0.32 Ω. Owing tothe stable properties and high relative spatial surface area of NGS, ions have a good contact rate andcharge exchange capacity between the electrode and the electrolyte interface, thereby ensuring a stablesupercapacitor capacitance..