▎ 摘　　要

NOVELTY - Graphene-carbon nano-tube film composite film comprises graphene film layer and carbon nano-tube film layer sequentially laminated along thickness direction, where the graphene film layer is composed of multiple layers of graphene and has thickness of 1-5 mu m. The thickness of the carbon nano-tube film layer is 8-12 mu m. USE - The graphene-carbon nano-tube film composite film is useful for preparing lightweight, flexible, high heat conducting and high conductive material (claimed). ADVANTAGE - The composite film: has in-plane thermal conductivity of more than 150 W/m/K, density of less than 0.5 g/cm3, electrical conductivity of 104-106 S/m, improved mechanical properties of 3-5 times, preferably 20-80 Mpa, elongation at break of 1-5% and good electrical conductivity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for (1) preparing graphene-carbon nano-tube film composite film, comprising taking carbon nano-tube film and graphene oxide dispersion, forming graphene oxide in the graphene oxide dispersion on carbon nano-tube film to obtain graphene oxide-carbon nano-tube film composite film, sequentially carbonizing and graphitizing graphene oxide-carbon nano-tube thin film composite film in a protective atmosphere to obtain light-weight, flexible, highly thermally conductive composite film; and (2) highly heat conducting material, comprising graphene-carbon nano-tube film composite film.