AMERICAN BORONITE CORPORATION — Department of Defense SBIR Phase I: A16-132

Description

Carbon nanotube (CNT)-based copper hybrid-conductors, density ~5 g/cc, at copper level conductivity potentially have an ampacity of two orders of magnitude above bulk copper. In this proposal, we posit that by improving CNT wire conductivity and coupling with copper infiltration we will achieve these goals. This extraordinary ampacity and conductivity come from suppressing electromigration coupled with the extreme charge-carrier mobility through the CNT pathways. Achievement of these goals encompass two processes: (1) Removing the fundamental structural/physical obstructions to charge carrier transport in CNT conductors by doping to a higher density of charge carriers, addressing alignment factors, atomically cleaning the surfaces, reducing the effect of Schottky barriers and minimizing growth defects through processing. Our goal is > 20 x 10^6 S/m for CNT yarn alone, and then (2) Infiltrating this CNT fiber with copper to take advantage of the very high CNT charge carrier mobility and high charge carrier density in copper. The demonstrated suppression of electromigration by CNTs within copper is key to ampacity increases. We will have a plied composite Cu/CNT cable fabricated commercially. A new manufacturing process to produce Cu/CNT hybrid wire by infiltrating molten copper inside the CNT fiber is described.