▎ 摘　　要

NOVELTY - Preparation of graphene involves mixing urea and magnesium powder in mass ratio of 1:(0.5-10), obtaining mixture, placing the mixture in an inert gas, heating to 700-1400 degrees C at rate of 2-50 degrees C/minute, heat-preserving for 1-20 hours, cooling the resultant product to room temperature, pickling, ultrasonically-treating, filtering and drying. USE - Preparation of graphene used as electrode material of lithium-ion battery, lithium-air battery and supercapacitor, fuel cell redox catalyst, and energy material. ADVANTAGE - The method enables economical, simple, easy and environmentally-friendly preparation of graphene.