Method for continuously preparing graphene heat-conducting films

A method for continuously preparing thermally conductive graphene films, comprising:

• 1) processing a graphite oxide containing 40 to 60 wt % of moisture into strips via a screw extruder, and then cutting into pellets to obtain graphite oxide particles;
• 2) stripping the graphite oxide particles of the step 1) at a high temperature to prepare graphene oxide powder;
• 3) dispersing the graphene oxide powder of the step 2) in a solvent to form a homogeneous graphene oxide slurry, wherein the graphene oxide slurry has a viscosity of 20000-100000 mPa·s and a fineness of less than 30 μm;
• 4) defoaming the dispersed graphene oxide slurry of the step 3) under vacuum;
• 5) coating the defoamed graphene oxide slurry of the step 4) on a substrate to form a graphene oxide film with a certain thickness, drying the graphene oxide film to remove the solvent, and then continuously winding to form coils;
• 6) stripping the graphene oxide film from the substrate of the coils of the step 5) via a stripping device, and then cutting the edges of the graphene oxide film by a trimming device to form continuous coils of graphene oxide film;
• 7) performing heat treatment on the continuous coils of graphene oxide prepared in the step 6) at the temperature of 150° C.-500° C., thereby realizing preliminary reduction of the graphene oxide film;
• 8) subjecting the preliminarily reduced graphene oxide film of the step 7) to the temperature of 2200 to 2800° C. for graphitization to obtain a graphitized graphene film;
• and
• 9) rolling the graphitized graphene film of the step 8) to increase the density to obtain the thermally conductive graphene films, wherein the pressure of the rolling ranges from 10 to 30 MPa.