Spanish researchers have developed a new material that could reduce the weight of electric vehicles (EVs), drones, and aircraft by replacing copper wiring. Published in Science, the research from the Institute of Nanoscience and Materials of Aragon and the IMDEA Materials Institute describes a chemical doping process that increased carbon nanotube conductivity 17-fold while preserving the fibers' structural integrity.
At ambient temperature, the treated fibers achieve about 40% of copper's electrical conductivity, but on a weight-adjusted basis their specific conductivity exceeds aluminum. The fibers weigh roughly one-sixth of copper while offering five times the tensile strength. Earlier versions of these fibers were known for being tough and lightweight but lacked sufficient current-carrying capacity, making this conductivity gain a key breakthrough.
The improvement came from treating the fibers with tetrachloroaluminate (AlCl4-), a dopant that introduces charge carriers without disrupting the atomic lattice—a longstanding challenge. Preserving structural integrity is critical, as a conductor that fails in service has no practical value.
Modern EVs carry significant copper loads, especially in high-voltage wiring bundles, adding substantial mass. Replacing some copper with a lighter material reduces vehicle weight, extends range, and lowers heat buildup due to reduced resistivity. In drones, reducing cable mass directly increases flight time, and for aircraft, weight savings yield significant returns.
The material also demonstrates reliable performance in dry conditions and acceptable moisture tolerance, which are important for transportation certification. On specific conductivity—the benchmark manufacturers prioritize—the treated fibers have entered a range that warrants engineering attention. At peak values, they even exceed aluminum's conductivity on an absolute basis.
The remaining challenges involve manufacturing consistent fibers at scale, ensuring compatibility with existing hardware, and achieving cost competitiveness with conventional metals. If these issues are resolved, the technology could move from laboratories into next-generation EVs and aircraft. Recycling infrastructure for these materials will also need development.
Many automotive companies, such as Ferrari N.V. (NYSE: RACE), will be watching to see if this material becomes commercially available at scale and at price points that make switching from copper economically viable.
