▎ 摘　　要

NOVELTY - Method for preparing graphite/graphene composite material by supercritical carbon dioxide fluid stripping, by mixing and stirring potassium permanganate and concentrated nitric acid and heating, adding natural large scale graphite, stirring, adding citric acid, reacting, adding hydrogen peroxide to react to remove excess potassium permanganate, washing, performing suction filtration, drying in vacuum oven to obtain expandable graphite and adding the expandable graphite to the high-pressure reactor, cooling the carbon dioxide to liquid state using refrigerator, pumping the carbon dioxide into the reactor using pressure pump, when the temperature and pressure in the high-pressure reactor reach the preset value, ultrasonically treating, intercalating the supercritical carbon dioxide molecules into the expandable graphite for a period of time, adopting the rapid pressure relief operation to reduce the pressure in the reactor to the atmospheric pressure to obtain the product. USE - The method is useful for preparing graphite/graphene composite material used in negative electrode material for lithium ion battery(claimed). ADVANTAGE - The method is simple to process, mild, environmentally-friendly, less damaged and economical, achieves high-yield, high-quality graphite and graphene composite material and has wide application prospects. DETAILED DESCRIPTION - Method for preparing graphite/graphene composite material by supercritical carbon dioxide fluid stripping, involves (i) continuously mixing and stirring required amount of potassium permanganate and concentrated nitric acid at 50 rpm and heating in a water bath, when the temperature rises to a certain condition, adding natural large scale graphite, continuously stirring for a period of time, adding citric acid, reacting, adding certain amount of hydrogen peroxide to react to remove excess potassium permanganate, and washing until neutral, performing suction filtration, drying in vacuum oven for 12 hours to obtain expandable graphite and (ii) adding the expandable graphite to the high-pressure reactor, cooling the carbon dioxide to liquid state using refrigerator, pumping the carbon dioxide into the reactor using pressure pump, when the temperature and pressure in the high-pressure reactor reach the preset value, ultrasonically treating, intercalating the supercritical carbon dioxide molecules into the expandable graphite for a period of time, adopting the rapid pressure relief operation to reduce the pressure in the reactor to the atmospheric pressure to obtain the product.