Asymmetric structure endows thermal radiation and heat conduction of graphene film for enhancing dual-mode heat dissipation

Abstract

To prevent heat accumulation generated by high power components inside spacecraft, it is necessary to encapsulate a heat dissipation material on the exterior surface of the spacecraft to homogenize local “heat point” and subsequently transfer it to aerospace.Hence, developing a flexible heat dissipation material with superior thermal radiation characteristics and thermal conductivity is essential for spacecraft thermal management under a vacuum environment. However, traditional heat dissipation materials are incapable to simultaneously satisfy these requirements. Here, we designed a double-layer asymmetric structure to achieve dual-mode heat dissipation of the graphene film, which is verified by FEA (Finite Element Analysis). For thermal radiation layer, the unique rose-like graphene with numerous defects can excite plasmon resonance, which can capture incident infrared wave effectively and make multiple reflection until fully absorbed. The high emissivity reaches 0.99 like blackbody across a wide wavelength range (2.5–18 µm). For thermal conductive layer, the orderly lattice structure facilitates the fast transfer of phonons, ensuring the high thermal conductivity of 1196 W m−1 K−1. These make it possess a better cooling effect compared with single graphene film. This work provides a new strategy to design composite with high thermal conductivity and infrared emissivity simultaneously for spacecraft thermal management. Keywords: Spacecraft thermal management, Heat conduction, Thermal radiation, Graphene film, Asymmetric structure, Dual-mode heat dissipation.