Controllable silver-ion implantation enhances electrical transport in carbon nanotube fibers

Carbon nanotube fibers (CNTFs) hold great promise as high-performance flexible conductors, yet their macroscale electrical conductivity is severely constrained by high intertube contact resistance. In this work, we employ lightweight CNTFs as substrates and introduce silver nanostructures via ion implantation to construct a conductive network. The resulting composite fiber exhibits a remarkable electrical conductivity of 2.2 × 107 S m−1 and a mass-specific conductivity of 12.7 × 103 S m2 kg−1, surpassing the benchmark values of copper. Microstructural analysis reveals that the implanted silver effectively reduces intertube contact barriers, thereby facilitating interfacial charge transport. Combining lightweight flexibility with exceptional conductivity, this composite fiber shows considerable potential for applications in electromagnetic interference shielding, flexible electrodes, and wearable electronics. Overall, our findings demonstrate that controllable ion implantation offers a viable route to the fabrication of high-performance conductive fibers.