Copper-formate seeding for scalable high electrical conductivity copper-carbon nanotube wires

Copper (Cu)–Carbon nanotube (CNT) composite wires can be used as conductive wires to reduce the weight of automobiles and aircraft. However, ensuring homogeneous Cu–CNT mixing during wire processing poses challenges in realistic application development of these materials. To address this issue, we developed a novel electroless plating process using a mixed solution of copper formate, propylene glycol, and 1-amino-2-propanol to seed Cu on CNTs. Electroplating was performed while winding the Cu-seeded CNT fibers, which solved the problem of inhomogeneity in the length direction caused by voltage drop. The specific conductivity of the Cu–CNT composite wire was 5.1 × 10 4 S cm 2 /g, which was comparable to that of the Cu wire (6.5 × 10 4 S cm 2 /g) and Cu–CNT composite wire (4.9 × 10 4 S cm 2 /g) fabricated using the conventional electroplating method. This study provides insights into the optimization and efficient production of conductive wires for various applications in the transportation industry.