▎ 摘　　要

NOVELTY - The method for preparing composite graphene electrothermal film involves adding graphene oxide solution, natural graphite, concentrated sulfuric acid and phosphoric acid in kettle, adding potassium permanganate, heating, adding hydrogen peroxide to bright yellow oxide graphite solution, washing, dispersing graphite oxide to prepare graphene oxide aqueous solution, extruding, adding coagulation liquid for coagulating into graphene oxide gel film, freezing, adding graphene aerogel film into furnace for heat treatment, heat preserving to obtain pure graphene aerogel film and pressing. USE - Method for preparing composite graphene electrothermal film (claimed). ADVANTAGE - The method enables preparation of composite graphene electrothermal film with high toughness, high conductivity, high machinability by simple and environmentally-friendly process, and achieves mass productivity of graphene. DETAILED DESCRIPTION - The method for preparing composite graphene electrothermal film involves adding graphene oxide solution, 250 g natural graphite, 4.5 l concentrated sulfuric acid and 0.5 l phosphoric acid in reaction kettle, stirring uniformly at temperature less than 20 degrees C using electronically controlled magnetic stirrer, slowly adding 500 g potassium permanganate, sealing reactor and heating at 85-90 degrees C for 2-3 hours, taking out product from bottom of the reactor, diluting into 40 l solution, adding 0.6 l hydrogen peroxide to bright yellow oxide graphite solution, alternating centrifugal washing with acid and water, adjusting pH of solution to 5-6, removing impurity ions, ultrasonically dispersing of graphite oxide to prepare graphene oxide aqueous solution, uniformly extruding aqueous solution of graphene oxide at a concentration of 5-15 mg/ml using in-line outlet, adding coagulation liquid or liquid nitrogen for coagulating for 10-100 seconds into graphene oxide gel film, adding graphene oxide gel film into -10 to -15 degrees C refrigerator, freezing for 2-5 hours or rapid freezing of liquid nitrogen, adding freeze-treated aerated graphene aerogel film into high temperature furnace for high temperature heat treatment, heating at 400 degrees C and 2-3 degrees C/minute in inert gas atmosphere, heat preserving for 0.5-1 hour, raising temperature to 1300 degrees C and rate of 2-4 degrees C/minute in inert gas atmosphere, heat preserving for 1-4 hours, raising temperature to 3000 degrees C and 2-4 degrees C/minute in inert gas atmosphere, heat preserving for 1-2 hours to obtain continuous ultra-light regular orientation of pure graphene aerogel film, pressing aerogel film at high pressure of 20-50 MPa.