Highly thermally conductive composites of graphene fibers

Carbon fiber-based polymer composites have rich electric and thermal functions, the merit of weight lightness to meet important applications in thermal management. Graphene fiber, a newly emerged carbonaceous fiber, features high thermal conductivity that surpasses conventional carbon fibers. For the realistic applications of Graphene fiber, fiber composite is one necessary form but still remains unexplored. Here, we prepared graphene fiber based polymer composites and achieved high specific thermal conductivity up to 363 W∙cm3∙m−1∙K−1∙g−1, outperforming composites of mesophase pitch-based carbon fiber. Graphene fiber composites with a fiber content of 59 vol% have a low density of 1.53 g∙cm−3 and high axial thermal conductivity of 553 W∙m−1∙K−1. For the high breakage elongation of graphene fiber, graphene fiber composites can be fabricated to adapt sharp curvature structures. This work develops polymer composites of graphene fiber and their high thermal conductivity can have extensive applications in thermal management.