▎ 摘　　要

NOVELTY - Preparing graphene comprises (1) dispersing graphite powder in organic solvent and performing grinding pre-treatment; (2) mixing the heating to the liquid hydrophilic ion liquid hydrophobic ion, liquid composite ion liquid; (3) removing the organic solvent from pre-treated graphite powder and uniformly mixing with composite ion liquid; (4) adding the mixture into high temperature and high pressure reaction kettle and introducing carbon-dioxide sealing protection and reacting; and (5) transferring the reactant to the ultrasonic reactor, adding 5-aminovaleric acid, and performing ultrasonic reaction. USE - The method is useful for preparing graphene using composite ion liquid. ADVANTAGE - The method improves grade of exfoliated graphene.