Production of highly-oriented graphite monoliths with high thermal conductivity

Three dimensional (3D) freestanding carbon-based networks (graphene networks, CNT networks, graphite networks, etc.) play an important role in many fields including composite reinforcing fillers, electrode materials, energy storage and template supports. Traditional methods for constructing these networks often require expensive equipment with complex processing, which is not suitable for large-scale production and commercialization. Herein, we proposed a facile strategy to construct highly oriented graphite (HOG) frameworks via one-step room-temperature acid expansion method without chemical modification or special treatment. This simple, economical and scalable method provides a new idea and route for fabricating the advanced carbon networks. The obtained HOG frameworks can be used as the thermal conductive fillers to prepare flexible HOG/polydimethylsiloxane (PDMS) composites with superior through-plane thermal conductivities, presenting a remarkably high thermal conductivity of 35.4 W m−1 K−1 at a filler content of 17.6 vol%. The HOG/PDMS composites were further applied in a heat energy management system in an electronic device, showing a much better heat dissipation than the commercial thermal conductive silica gasket. The excellent through-plane thermally conductive performance demonstrates great potential for the design and preparation of thermal interface materials via a facile expansion approach that is suitable for large-scale production and commercialization.