▎ 摘　　要

NOVELTY - Preparing nitrogen-doped three-dimensional graphene material comprises (i) dispersing graphene oxide in formaldehyde solution, and then adding cysteine to obtain dispersion A, (ii) dispersing melamine in deionized water to obtain dispersion B, (iii) mixing dispersion A and dispersion B, heating at 50-80 degrees C for 10-60 minutes, adjusting the pH of the reaction solution to 7-9, then heating up in a closed air for hydrothermal reaction, and drying the product to obtain aerogel, (iii) mixing dispersion A and dispersion B, heating at 50-80 degrees C for 10-60 minutes, adjusting the pH of the reaction solution to 7-9, then heating up in a closed air for hydrothermal reaction, and drying the product to obtain aerogel, and (iv) placing the aerogel obtained in step (iii) in the microwave reaction chamber, heating with microwave power of 300-1200 W for 10-60 minutes to obtain nitrogen-doped three-dimensional graphene material. USE - The material is useful as cathode material for lithium ion batteries (claimed). ADVANTAGE - The material: avoids the loss caused by the sublimation of the nitrogen-doped precursor in the traditional nitrogen-doped process; improves the efficiency of nitrogen doping; has good stability; does not easily denatured in the air, and easy to store; and has large specific surface area; provides good channel for lithium ion transmission; shows larger specific capacity and better cycle stability. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for nitrogen-doped three-dimensional graphene material prepared by above mentioned method.