▎ 摘　　要

NOVELTY - A high-strength flexible graphene heat-conductive composite film is obtained by overlapping polymer composite graphene films having high planar orientation, density of 1.8-2 g/cm3 and average size of more than 100 mu m by ( pi ),( pi )-conjugation. In polymer composite graphene film, polymer is bonded to graphene sheet by pi -conjugation or chemical bonding. USE - High-strength flexible graphene heat-conductive composite film is used for heat electric conduction device. ADVANTAGE - The high-strength flexible graphene heat-conductive composite film has breaking elongation rate of 6-16% and conductivity of 6000-8600 S/cm. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of high-strength flexible graphene heat-conductive composite film. 1 Part mass oxidized graphene having average size of more than 100 mu m and 0.01-1 pt. wt. organic polymer are mixed to obtain aqueous solution of graphene oxide having concentration of 6-30 mg/mL. To the resultant solution, 0.1-5% inorganic salt as additive is added. The resultant mixture is ultrasonically dispersed and dried to form oxidized graphene film. The resultant film is reduced using reducing agent under inert gas atmosphere. The resultant material is heated at 1000-1300 degrees C under inert gas atmosphere, heat-preserved for 0.5-3 hours, further heated at 2500-3000 degrees C at the rate of 5-8 degrees C/minute under inert gas atmosphere, heat-preserved for 0.5-4 hours, and naturally cooled, to obtain porous graphene film. The obtained film is processed under high pressure to obtain high-strength flexible graphene heat-conductive composite film.