Boosting the Heat Dissipation Performance of Graphene/Polyimide Flexible Carbon Film via Enhanced Through‐Plane Conductivity of 3D Hybridized Structure

Abstract The development of materials with efficient heat dissipation capability has become essential for next‐generation integrated electronics and flexible smart devices. Here, a 3D hybridized carbon film with graphene nanowrinkles and microhinge structures by a simple solution dip‐coating technique using graphene oxide (GO) on polyimide (PI) skeletons, followed by high‐temperature annealing, is constructed. Such a design provides this graphitized GO/PI (g‐GO/PI) film with superflexibility and ultrahigh thermal conductivity in the through‐plane (150 ± 7 W m ‐1 K ‐1 ) and in‐plane (1428 ± 64 W m ‐1 K ‐1 ) directions. Its superior thermal management capability compared with aluminum foil is also revealed by proving its benefit as a thermal interface material. More importantly, by coupling the hypermetallic thermal conductivity in two directions, a novel type of carbon film origami heat sink is proposed and demonstrated, outperforming copper foil in terms of heat extraction and heat transfer for high‐power devices. The hypermetallic heat dissipation performance of g‐GO/PI carbon film not only shows its promising application as an emerging thermal management material, but also provides a facile and feasible route for the design of next‐generation heat dissipation components for high‐power flexible smart devices.