Ultra-conductive copper carbon composites: Scalable solid-phase processing with coal-derived carbon allotropes

Copper remains the material of choice for electrical wire applications due to its excellent electrical conductivity and favorable mechanical properties, making it essential for electric motors, electronic devices, and power distribution networks. While recent advancements in copper conductivity have the potential to enhance energy transport efficiency, reduce weight, lower costs, and minimize emissions, many approaches rely on expensive carbon materials, limiting their scalability and commercial viability. This study presents, for the first time, a cost-effective ultra-conductive copper-carbon composite (UCCC) material with measurably enhanced electrical performance. Various coal-derived carbon allotropes were incorporated into copper (C110) using a novel solid-phase hot-extrusion process to fabricate 12 American wire gauge (AWG) composite wires with varying carbon contents. The addition of 0.05 wt.% coal-derived graphene increased electrical conductivity by 1.7% compared to commercial copper wire. Furthermore, coal-derived carbon allotropes demonstrated higher conductivity improvements, up to 1.2% greater than those achieved with commercial carbon materials, while offering a substantial economic alternative. Mechanistically, the observed enhancement suggests that shear during processing facilitated exfoliation of the turbostratic coal-derived carbons, leading to more effective conductive pathways. In contrast, commercial graphene appears more susceptible to structural degradation under similar shear conditions, offering a possible explanation for the superior performance achieved using low-cost, coal-derived carbons. These findings highlight the potential of coal-derived carbons as an affordable and scalable solution for enhancing the electrical conductivity of copper, offering a viable pathway for widespread implementation in energy and electrical applications.