An amorphous-crystallization strategy towards high-quality graphene for constructing highly conductive Cu matrix composites

High-quality graphene (HQG)-Cu composites demonstrate remarkable properties; however, there remains a scarcity of preparation methods that are both simple and efficient for large-scale industrial application. Herein, amorphous graphene-like carbon (AGLC) synthesized on Cu powders using affordable solid carbon sources (SCS) was successfully converted into HQG inside the unconsolidated Cu skeletons by simple cold pressing combined with high-temperature hydrogen annealing technology. The HQG-Cu composites densified by spark plasma sintering exhibit repeatable high electrical and thermal conductivity (∼433 Wm -1 K -1 ). Importantly, it demonstrates a remarkable enhancement of ∼23% in thermal conductivity efficiency (per volume fraction of graphene). Compared with the original AGLC-Cu composites, the electrical conductivity of HQG-Cu composite has increased substantially, rising from 91.5 to 100.6 %IACS. Furthermore, such new design avoids the conflict between the high-temperature growth of HQG (above 1000 ) and the welding of Cu powders (about 1000 ). The conversion mechanism from SCS to HQG involving the competition between Cu catalysis and hydrogen etching is clearly revealed. Our research demonstrates the potential of SCS-converted HQG-Cu composites for industrial application, providing a promising avenue for further development of graphene-Cu composites.