▎ 摘　　要

NOVELTY - Preparing graphene composite thermally conductive film includes: placing flake graphite in concentrated sulfuric acid, soaking a mixture of potassium persulfate and phosphorus pentoxide overnight, filtering and drying; oxidizing pre-oxidized graphite fully in concentrated sulfuric acid and potassium permanganate, followed by adding deionized water, after suction filtering and washing repeatedly; thermal spraying the aqueous solution of the graphene oxide coating on a substrate; reducing graphene oxide films to obtain graphene film; and coating treatment of graphene films. USE - The method is useful for preparing graphene composite thermally conductive film. ADVANTAGE - The method provides the thermally conductive film with good thermal performance by a simple method at less cost. DETAILED DESCRIPTION - Preparing graphene composite thermally conductive film comprises: placing flake graphite in concentrated sulfuric acid, soaking a mixture of potassium persulfate and phosphorus pentoxide overnight, filtering and drying to complete pre-oxidation; using Hummers method oxidizing pre-oxidized graphite fully in concentrated sulfuric acid and potassium permanganate, followed by addition of deionized water, after suction filtering and washing repeatedly, to obtain an aqueous solution of graphene oxide; thermal spraying an aqueous solution of the graphene oxide coating on the substrate, to obtain graphene oxide deposited thin film; reducing graphene oxide films to obtain graphene film; and coating treatment of graphene films to obtain the conductive film. INDEPENDENT CLAIMS are also included for the graphene composite thermally conductive film comprising either: successively bonding, a heat insulating layer of 3-10 mu m, an adhesive layer A, graphene layer of 50 mu m, copper foil substrate of 12-70 mu m, an adhesive layer B and a release paper, where the adhesive layers A and B are of less than or equal to 10 mu m; or a flexible substrate of 312 mu m, an adhesive layer C, graphene layer of 50 mu m, an adhesive layer D and a release paper, where the adhesive layers C and D are of less than or equal to 10 mu m.