Highly Conductive Double‐Wall Carbon Nanotube Fibers Produced by Dry‐Jet Wet Spinning

Abstract Carbon nanotube fibers (CNTFs) are considered an ideal candidate as next‐generation conducting wires due to their high conductivity and low density. However, the orientation and compaction of the nanotubes in a CNTF need to be further improved to achieve even higher conductivity and ampacity. Here the fabrication of double‐wall CNTFs (DWCNTFs) is reported by a dry‐jet wet spinning method, which significantly improves the orientation and compaction of the carbon nanotubes (CNTs). As a result, the obtained DWCNTFs have a record high electrical conductivity of 1.1 × 10 7 S m −1 and ampacity of 8.0 × 10 8 A m −2 . The fibers also have a high tensile strength of 1.65 GPa and a toughness of 130.9 MJ m −3 , among the highest for wet‐spun CNTFs. The DWCNTFs preserve their integrity and conductivity after more than 5000 bending cycles. Theoretical calculations indicate that in a dry‐jet wet‐spinning process, gravity promotes the orientation of the CNTs along the axial direction of the fiber.