AA6101-Graphene Composites with Enhanced Electrical Performance for Electric Grid Applications

Transmission and distribution losses in electric grid account for ~5 - 10% (250 TWh) of energy generated in the US annually, as of 2020. There is a critical need for developing aluminum alloys for use in energy efficient power transmission infrastructure. Improved electrical performance, at high temperatures especially, is essential to minimize resistive heating losses under typical operating conditions for transmission and distribution systems, which may go as high as 90 °C for busbar materials.

Using graphene nanoparticles as additives which create high carrier velocity pathways, we extruded AA6101 composites wires with enhanced electrical conductivity at operating at operating temperatures. AA6101 is a popular high strength/high conductivity heat treatable alloy used in power transmission structures like busbars. Understanding the interactions between the aluminum substrate, intermetallic phases, and the graphene nanoparticle additives is crucial to identify composite formulations and process parameters which facilitate enhanced performance commercial aluminum alloy composite synthesis in bulk, scalable profiles. Aluminum/graphene composites with 0.05 wt.% graphene demonstrated an electrical conductivity increase of increase of 1% at 20 °C and a maximum TCR decrease of 8.5% in the as-extruded condition. SEM imaging showed the effect of graphene on precipitate dynamics of aluminum substrates during extrusion.