Bidirectionally High-Thermally Conductive and Environmentally Adaptive Graphene Thick Films Enabled by Seamless Bonding Assembly for Extreme Thermal Management

With the rapid development of high-power electronics in aerospace, communication, and energy storage systems, the huge heat flux poses an increasing threat to the safety of electronic devices. Compared with thin films of a few micro thicknesses, high-quality graphene thick film (GTF) exceeding hundreds of microns thickness is a promising candidate to solve thermal management challenges owing to higher heat-flux. However, traditional GTF usually has lower thermal conductivity and weak mechanical properties attributed to disordered sheet alignment and frail interfacial adhesion. Here, a seamless bonding assembly (SBA) strategy is proposed to attain GTF over record hundreds of microns with robust coalescence interfaces. For the GTF-SBA with approximate to 250 mu m thickness, the in-plane and through-plane thermal conductivities are 925.75 and 7.03 W m-1 K-1, approximately two times and 12 times those of the GTF prepared by traditional adhesive assembly method, respectively. Furthermore, the GTF-SBA demonstrates remarkable stability even after cycled harsh temperature shocks from 77 to 573 K, ensuring its environmental adaptability for long-term service in extreme conditions. These findings provide valuable insights into the interfacial design of graphene bulk materials and highlight the potential applications of high-performance graphene-based materials for extreme thermal management demands. Bidirectionally high-thermally conductive graphene thick film is achieved by a reliable seamless bonding assembly strategy. The graphene thick film with 250 mu m demonstrates record kappa parallel to of 925.75 W (mK)-1 and kappa perpendicular to of 7.03 W (mK)-1, meanwhile exhibiting remarkable stability even after hundreds of cycled harsh temperature shocks from 77 to 573 K, ensuring its environmental adaptability for extreme thermal management. image