Ultrahigh Thermal Conductivity of Epoxy Composites with Hybrid Carbon Fiber and Graphene Filler

With the advancement of technology, the tendency towards multifunctional and smaller size electronic devices is increasing rapidly, thus heat removal is crucially needed. Carbon fiber and graphene are the most promising materials being used as thermal conductive filler for this purpose. Herein, random carbon fiber/graphene epoxy composites (R-CF/G Ep) and vertically aligned carbon fiber/graphene epoxy composites (V-CF/G Ep) were constructed. The difference of thermal conductivity between two methods at various filler loading was investigated. With 30 wt% filler loading, the thermal conductivity of R-CF/G Ep was only 7.4 W m−1 K−1. While the V-CF/G Ep presented ultrahigh thermal conductivity of 21.19 W m−1 K−1 due to synergistic effect of carbon fiber and graphene. In this work, a promising method taking full advantage of axes thermal conductivity of CF is revealed.