Maximising the electrical conductivity of graphite films based on graphene oxide and blade-coating

Abstract Achieving high electrical conductivity with graphene oxide based conductors remains a challenging task. Here, film fabrication by blade-coating was chosen as a fast and scalable method. The influence of different fabrication parameters like application speed, blade slit height, and shear stress on the electrical conductivity were evaluated. A shear stress of around 40 Pa to 60 Pa seems to increase the electrical conductivity by about 200 % for slit heights of 30 μ m to 60 μ m compared to 1000 μ m. But we determined for each set of fabrication parameters the possible maximum of the electrical conductivity. The maximum clearly increases with decreasing slit height. The use of slit heights of 30 μ m yields a possible maximum of 640 kS/m close to the theoretical maximum at slit heights approaching 0 μ m of 677 kS/m. Slit heights in the range of the graphene oxide flake size force mechanically the flakes to align. Our work reveals that slit heights in the range of the graphene oxide flake size are detrimental to control the electrical conductivity rather than shear stress, paving the path for highly electrically conductive graphene oxide based graphite films.