Vibration-assisted high-temperature remelting chemical vapor deposition synthesis of micron-sized spherical graphene-skinned Cu powder

The substitution of silver (Ag) powder with copper (Cu) powder in electronic pastes is severely hindered by the high susceptibility to oxidation of Cu. The practical application of conventional passivation layers is constrained by interfacial delamination, microstructural defects, and poor cost-effectiveness. The high-temperature remelting chemical vapor deposition method can be used to synthesize micron-sized spherical graphene-skinned Cu powder (Gr-Cu). By combining dual vibration to disrupt the agglomerates of micron-sized Cu powder, a few-layer graphene passivation layer with uniform coverage and high crystallinity was obtained. Low-temperature sintering of Gr-Cu at 400°C was achieved by nano-Ni-assisted welding. The graphene skinning maintained good coverage after sintering and formed a continuous 3D honeycomb-like network. Comparative analysis against raw Cu and Ag-coated Cu powder demonstrates that Gr-Cu possessed comprehensive advantages of cost-effectiveness, electrical conductivity, oxidation resistance, and acid stability. This work provides a new way for the development of next-generation electronic paste.