Advanced Material for Electrical Power Cables

We develop new classes of conducting materials consisting of metal-coated and metal-infiltrated carbon-nanotube wire, with a goal of achieving densities less than 2 g/cm3, specific conductivities exceeding copper and the ability to carry very high current. Quantum effects in CNT wire and consequent ballistic conduction coupled with the high electron density of copper enables a new kind of non-rule of mixtures wire that can exhibit extraordinary properties. Most Army cables need improved conductivity, reduced mass density, and flexibility. A few Army applications use copper at extreme current densities and temperatures where electromigration limits performance, rail guns cables for example. Both conductivity and high current density are addressed. We focus on four cable types: (1) We create a CNT wire made of predominantly metallic conducting nanotubes, (2) We fabricate a dual metal coated CNT wire with a linker element and copper, (3) We create copper- and/or aluminum-infiltrated CNT wire for applications requiring fully dense conductors (e.g. dictated by electromigration concerns), and (4) We create an aluminum coated CNT wire which, in Phase I, has demonstrated current carrying capacity higher than aluminum. We have partnered with Lockheed-Martin and Minnesota Wire for both commercialization scale-up as well as for cable fabrication.