▎ 摘　　要

NOVELTY - Preparing nitrogen-doped graphene, comprises mixing a solution of graphene oxide with hexamethylenetetramine, and carrying out a hydrothermal reaction on the graphene oxide in which an amine derivative is incorporated, to prepare the nitrogen-doped graphene. USE - The method is useful for preparing nitrogen-doped graphene that is useful as an electrode active material of an electricity storage cell (all claimed) such as super capacitor and ultra capacitor. ADVANTAGE - The nitrogen doped graphene can be economically prepared, and improves storage capacity and specificity of the super capacitor. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) an electricity storage cell containing the nitrogen-doped graphene; and (2) manufacturing an electrode, comprising mixing the nitrogen-doped graphene with binder in a solvent to prepare a paste, and coating an electrode surface using the paste.