Ultrahigh-thermal-conductivity graphene thick film with vertical micropores, and preparation method of ultrahigh-thermal-conductivity graphene thick film

The invention discloses a graphene thick film with vertical micropores and ultrahigh thermal conductivity in a plane direction, and a preparation method of the graphene thick film. The preparation method comprises the following steps: coating a thick film with a graphene oxide hydrosol, drying at a low temperature until the water content is 50%-70%, then implanting low-melting-point EVA short fibers into the thick film in the Z-axis direction by utilizing electrostatic flocking, drying, then heating until the short fibers are molten, leaving vertical micropores in the graphene oxide film, andcarrying out heat treatment reduction to obtain the ultrahigh-thermal-conductivity graphene thick film with the vertical micropores. Accoording to the preparation method, vertical micropores are implanted into a graphene oxide thick film precursor, so that gas generated in subsequent heat treatment reduction is easy to overflow, and in-film defects caused by a cavity left by generated gas are reduced so as to improve the