Edge-nitrogenated graphene nanoplatelets (ENGNPs) with high surface area were prepared through a simple and eco-friendly mechanochemical pin-grinding process using the flake graphite as the precursors in the presence of nitrogen and investigated as the electrode materials for supercapacitors. Nitrogen adsorption, SEM, and XPS analysis indicated that the mechanochemical pin-grinding process can effectively delaminates the pristine graphite into graphene nanoplatelets and generates the activated carbon sites that can directly react with nitrogen at the broken edge of graphite framework, leading to ENGNPs with excellent capacitive performance. Electrochemical measurements indicate that the as-prepared ENGNPs exhibits a high specific capacitance of 202.8 Fg(-1) in 1 M H2SO4 aqueous electrolyte at the current density of 0.3 Ag-1, meanwhile maintaining a good capacitance retention capability. The excellent capacitive performance of ENGNPs can be attributed to the combined effect of high surface area, edge-nitrogenated structure, and undamaged basal plane. (C) 2016 Elsevier Ltd. All rights reserved.