▎ 摘　　要

Recently, three-dimensional graphene foam has received considerable attention and displayed excellent properties as reinforcement for polymer composites. However, the brittleness and poor controllability limited its application in resin to form conducting pathways for phonons and electrons. This study developed a facile method with compressible and constitutionally stable commercial melamine foam (MF) as template to prepare a core-shell composite with carbon skeleton structure. The core carbon structure was fabricated by carbonization of MF, while the shell carbon structure was the in-situ self-assembled coating of graphene. Vacuum-impregnated method was employed to fabricate epoxy resin composites. The thermal and electrical conductivities of epoxy composites were significantly increased to 0.92 W/(m.K) and 0.70 S/cm, which was 318% and 13 orders of magnitude higher than that of pure epoxy. Herein, we provide a highly efficient, green, high-quality method for building a double-layer heat conduction path, which facilitates the utilization of graphene. The proposed method proves to be efficient in enhancing the multifunctionality of epoxy resin composites. Furthermore, we explored the thermal and electrical conductive mechanisms of the three-dimensional core-shell structure in resin matrix.