Synergistically improved mechanical, thermal, and ampacity performances of carbon nanotube/copper composite conductors based on network confinement effects

Abstract

To solve the problem of limited ampacity (current-carrying capacity) for pure metals, composite conductors are developed by integrating copper into macroscopic carbon nanotube (CNT) assemblies via a refined two-step organic–aqueous electrodeposition and a consequent hot compression. Due to the network-based structural confinement, efficient transport pathways are established for load and heat, leading to the enhanced strength and thermal conductivity. Another confinement effect, namely confined Cu fusing, is revealed to be the major mechanism for the remarkably improved ampacity. As compared to Cu wires and strips whose ampacity is 6.8–9.7×104 Acm−2, the composite conductors exhibited a much higher value of 2.5–4.0×105 Acm−2. By considering the high electrical conductivity (81.4% IACS) and reduced mass density (96% that of Cu) as well, this work provides a promising electrical material for high electric power applications.