Enhanced electrical conductivity in graphene/copper laminates: Fabrication, characterization, and first-principles study

Copper (Cu) and its composites are widely employed in the electrical manufacturing industry. Among them, graphene (Gr)/Cu composites have emerged as a promising material system for the development of lightweight conductors with high electrical conductivity. In this work, based on a balance between cost and practicality, a new preparation method is proposed. Gr layers were first grown on Cu surfaces via chemical vapor deposition (CVD). The Cu foils with grown Gr layers were then stacked and consolidated by vacuum hot pressing, followed by annealing, to fabricate Gr/Cu laminated composites. As a result, an electrical conductivity of up to 106.4% IACS was achieved. The proposed process offers a straightforward and practical route for the fabrication of Gr/Cu composites. Furthermore, a simulation model of Gr/Cu laminates was established to investigate the effects of Gr stacking configuration and layer number on interfacial strength and electrical transport behavior. The results reveal that monolayer Gr, which is located between Cu-Cu layers, provides the optimal balance between interfacial strength and electrical conductivity. These findings highlight the importance of controlling the Gr layer number in order to simultaneously achieve high performance and cost-effective fabrication of Gr/Cu laminated composites.