Energy storage breakthrough: New carbon nanotube wires show record conductivity
Researchers in China have created a highly durable carbon nanotube that claims to offer record-breaking conductivity. The double-wall carbon nanotube fibers (DWCNTFs) are made using a “dry-jet wet spinning” method, which significantly enhances the alignment and density of the carbon nanotubes.
The resulting DWCNTFs exhibit a record-breaking electrical conductivity of 1.1 × 10⁷ S/m and can carry a high current density of 8.0 × 10⁸ A/m². They also feature a strong tensile strength of 1.65 GPa and a toughness of 130.9 MJ/m³, which are among the best for wet-spun carbon nanotube fibers.
According to the team at Shenyang National Laboratory for Materials Science, the material may be used in aerospace and other critical industries, including energy storage.
The dry-jet wet spinning method improves fiber quality by better-aligning polymers and reducing cracks, which are key factors affecting fiber performance. The technique achieves high conductivity and reasonable strength but still falls short compared to individual CNTs due to contact resistance and weak interactions between them.
In the study, researchers used this method to make DWCNTFs with high conductivity and ampacity. They successfully spun long, high-molecular-weight DWCNTs with a stable air gap, achieving excellent alignment and density.
The team’s research reveals that their fibers achieve record-high electrical conductivity, reaching 86 percent of copper’s conductivity, a benchmark for excellent electrical performance. In addition to their impressive conductivity, the fibers exhibit a tensile strength of 1.65 GPa, one of the highest fibers produced by this method.
The researchers also evaluated the fibers’ durability and found that both their integrity and conductivity were maintained even after more than 5,000 bending cycles.
Source: https://interestingengineering.com/innovation/energy-storage-carbon-nanotube-record-conductivity