▎ 摘　　要

NOVELTY - The preparation method of manganese-oxide porous graphene composite material involves taking graphite, concentrated sulfuric acid and potassium permanganate as raw material to prepare graphite oxide using chemical oxidation, ultrasonically processing or stirring, and drying to prepare pre-purified graphene oxide powder, high-temperature calcining the prepared powder, vaporizing the potassium ion in the pre-purified graphene oxide powder during calcination, performing sulfur ion gasification along with waste gas, and leaving the manganese ion on the surface of graphene oxide. USE - Preparation method of manganese-oxide porous graphene composite material for preparing porous graphene (claimed) lithium-air battery. ADVANTAGE - The method enables preparation of manganese-oxide porous graphene composite material with excellent performance, in short period, by simple, economical and industrial process. DETAILED DESCRIPTION - The preparation method of manganese-oxide porous graphene composite material involves (A) taking graphite, concentrated sulfuric acid and potassium permanganate as raw material to prepare graphite oxide using existing method of chemical oxidation, where the chemical oxidation method requires several times of natural sedimentation to reach viscosity, ultrasonically processing or stirring, and drying to prepare pre-purified graphene oxide powder, and (B) high-temperature calcining the pre-purified graphene oxide powder prepared in the step (A) in a high-temperature sintering furnace under inert gas protection, vaporizing the potassium ion in the pre-purified graphene oxide powder during calcination, performing sulfur ion gasification along with waste gas, and leaving the manganese ion deposited on the surface of graphene oxide. An INDEPENDENT CLAIM is included for preparation method of porous graphene, which involves (C) immersing the manganese oxide-porous graphene powder prepared in the step (B) in diluted hydrochloric acid, stirring at room temperature, removing surface oxide, suction-filtering until the pH value is 7, and vacuum drying.