Enhancing Electrical and Thermal Conductivity of Cu/Graphene Composites via Cobalt‐Mediated Interfacial Engineering

ABSTRACT

To address the critical challenge of poor interfacial compatibility and the difficulty of synergistically enhancing electrical/thermal conductivity and mechanical properties in copper–graphene composites, this study proposes a novel cobalt‐mediated interfacial engineering strategy. Using polydopamine as a carbon–nitrogen precursor combined with a trace amount of cobalt catalyst, in situ polymerization on copper powder, followed by sintering, controllable formation and robust interfacial bonding of nitrogen‐doped graphene within the copper matrix were successfully achieved. The results indicate that cobalt plays a dual role in catalytic graphitization and interfacial bridging: it not only significantly improves the crystallinity of graphene but also forms a strongly chemically bonded bridging phase at the copper–carbon interface. Benefiting from this unique interfacial structure, the Co‐5Gr/Cu composite demonstrates a synergistic breakthrough in electrical, thermal, and mechanical properties: the electrical conductivity reaches 95.25% IACS (International Annealed Copper Standard), the thermal conductivity attains 437 W m ⁻¹  K ⁻¹ (1.16 times that of pure copper), and the microhardness reaches 92.25 HV (Vickers Hardness), which is 9.60% higher than that of pure copper. This work provides a new interface‐regulation approach and a feasible preparation route for designing high‐performance metal–matrix composites.