High-conductivity carbon nanotube fibers via wet spinning of long carbon nanotubes

Abstract Carbon nanotube (CNT) fibers are promising lightweight conductors, yet their electrical conductivity remains limited compared with metallic benchmarks. Here, we demonstrate the fabrication of highly aligned and densely packed CNT fibers by wet spinning CNTs with long effective lengths. Wet-spun fibers prepared from chlorosulfonic acid dispersions exhibit an as-spun conductivity of 11.4 MS m −1 . Subsequent doping with fuming nitric acid increases the conductivity to 15.9 MS m −1 , representing one of the highest values reported for wet-spun CNT fibers. These results establish effective nanotube length and high packing density as key design parameters for high-performance lightweight conductors.