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

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.