The invention discloses a method for preparing a flexible high-
conductivity graphene film, belongs to the field of
graphene films, and aims to solve the technical problems that the size of conventional
graphene sponge is limited by equipment and the graphene
sponge is poor in flexibility in practical application. The method disclosed by the invention comprises the following steps: I, freezing an oxidized graphene dispersing solution for 10-24 hours at minus 50 DEG C to minus 20 DEG C, and performing freeze-
drying for 72-100 hours so as to obtain oxidized graphene
sponge; II, reducing the oxidized graphene sponge by using hydrazine
hydrate steam; III, in the presence of an
inert gas as a protection gas, performing
thermal treatment; IV, performing pressurization treatment, thereby obtaining the graphene film. The method disclosed by the invention is simple in process, low in cost, high in production efficiency and good in
controllability, a large-size sample can be prepared, different
engineering requirements can be met, and the situation that conventional large-size graphene sponge is limited by experiment equipment is solved; in addition, the graphene film which is good in flexibility, high in
conductivity and high in density is prepared by using the method.