▎ 摘　　要

NOVELTY - The preparation method of porous graphene involves soaking straw-based biomass in aqueous solution of nickel salt and then drying at 40-100 degrees C, processing the mixture and then carbonizing at 350-500 degrees C, immersing the mixture in aqueous solution of alkali and then activating at 600-1000 degrees C, cooling the mixture, and washing. USE - The method is useful for preparation of porous graphene, which is useful as capacitor (claimed). ADVANTAGE - The method enables simple preparation of porous graphene with high yield and excellent large specific surface area, conductivity and capacitance performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for use of porous graphene as capacitor.