High ampacity of superhelix graphene/copper nanocomposite wires by a synergistic growth-twisting-drawing strategy

Abstract

Nanocarbon materials can provide effective reinforcement to a surrounding composite matrix. However, the fabrication of nanocarbon/metal composites with superior comprehensive properties remains challenging. Here, we developed a simple cyclic growth-twisting-drawing method to fabricate superhelix graphene/copper nanocomposite wires composed of massive, strongly bonded, and super-helically arranged fine copper fibers with interfacial graphene layers. The obtained nanocomposite wires with a small graphene volume fraction of ∼0.32% exhibit a largely improved current carrying capacity of 5.8 × 1010 A m−2, ∼2.6 times of that of pure copper wires. Furthermore, the electrical conductivity, 5.01 × 107 S m−1, is comparable to that of pure copper. These nanocomposite wires also exhibit improved strength and ductility, 10% and 80% increases compared with that of pure copper wires. These multiple enhanced properties can be attributed to the microscopic superhelix structure with the interfacial graphene layers embedded in the entire multi-level structure. With their largely improved current carrying capacity and mechanical reinforcement, these highly electrically conductive nanocomposite wires promise widely potential applications in the areas of heavy duty, high power electronics and electricity transmission.