Scientists at PNNL working to improve aluminium’s conductivity

Keerti Kappagantula, Pacific Northwest National Laboratory (PNNL) materials scientist and his team are working to improve aluminium’s conductivity so that it can compete with copper inexpensively. Keerti stated that this study was initiated as a result of his team's realisation that the demand for copper is surpassing its existing supply, particularly as the EV revolution gains traction.

The research, in the opinion of the experts, opens the door to trials that, if completely realised, might result in an ultra-conductive aluminium substitute for copper that would be beneficial in markets outside of transmission lines, transforming automobiles, electronics, and the power grid.

“What if you could make aluminum more conductive—even 80% or 90% as conductive as copper? You could replace copper and that would make a massive difference because more conductive aluminum is lighter, cheaper, and more abundant. That’s the big picture problem that we’re trying to solve,” said Keerti Kappagantula, PNNL materials scientist and co-author of the research.

They decided to do something to improve the metal's conductivity after learning that aluminium is only around 60 per cent as conductive as copper but is just one-third the price and weight of copper.

“Conductivity is key because a lighter weight wire with equivalent conduction can be used to design lighter motors and other electrical components, so your vehicle can potentially go longer distances. Everything from a car’s electronics to energy generation to transmitting that energy to your home via the grid to charge your car’s battery—anything that runs on electricity—it can all become more efficient,” added Kappagantula.

The expert claimed that for many years it was thought that metals couldn't be made more conducive. However, it is now understood that metals' characteristics may be altered by changing their structure and adding the appropriate chemicals.

Kappangantula and post-doctoral researcher Aditya Nittala collaborated with David Drabold and Kashi Subedi of Ohio University to identify the effects of temperature and structural flaws on aluminium conductivity and develop an atom-by-atom recipe to increase its conductivity. This was done to start figuring out just how much aluminium conductivity could be increased.

The researchers were inspired by semiconductors since earlier work had successfully approximated conductivity in these silicon-based materials and some metal oxides because this sort of molecular modelling had never been done for metals.

The group then modified these ideas to work with aluminium and performed simulations to see what would happen to the conductivity of the metal if certain atoms in its structure were removed or changed. The overall conductivity increased noticeably as a result of these minute adjustments.

The researchers now have a clear theoretical formula for changing metal conductivity, and they intend to test how much more conductivity they can get out of aluminium in the lab to match theory with experiment. Using the same models, they are now looking at the prospect of making other metals more conductive.