Preparation method of composite heat conduction graphene film and composite heat conduction graphene film

The invention discloses a preparation method of a composite heat conduction graphene membrane and the composite heat conduction graphene film. The preparation method comprises the following steps: S1, putting crystalline flake graphite or graphite powder into a mixed solution of concentrated sulfuric acid, potassium persulfate and phosphorus pentoxide, soaking for a day and a night, then carrying out suction filtration, drying, and carrying out pre-oxidizing; S2, oxidizing pre-oxidized graphite further by adopting a Hummers method, that is, oxidizing fully in concentrated sulfuric acid and potassium permanganate, then adding deionized water for diluting, and carrying out repeated washing and suction filtration, so as to obtain an oxidized graphene aqueous solution; S3, spraying the oxidized graphene aqueous solution on a substrate by adopting a thermal spray method, and depositing, so as to obtain an oxidized graphene film; S4, reducing the oxidized graphene film, so as to obtain the graphene film; and S5, laminating the graphene film, so as to obtain the composite heat conduction graphene film. Compared with the prior art, the preparation method is simple, the cost is low, and the prepared composite heat conduction graphene film has a favorable heat conduction performance.