Cooking Up a Conductive Alternative to Copper with Aluminum

Aluminum is just one-third the price and weight of copper, but it is only about 60% as conductive. Aluminum’s relatively low conductivity can be a limitation in some real-world applications. 

“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,” said Kappagantula. “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.”  

Increasing aluminum’s conductivity would be a game-changer.

“For years, we thought metals couldn’t be made more conductive. But that’s not the case,” explained Kappagantula. “If you alter the structure of the metal and introduce the right additives, you can indeed influence its properties.” 

To begin figuring out just how much aluminum conductivity could be increased, Kappangantula and PNNL post-doctoral scholar Aditya Nittala teamed up with Distinguished Professor David Drabold and graduate student Kashi Subedi of Ohio University to identify the effects of temperature and structural defects in aluminum conductivity and develop an atom-by-atom recipe to increase its conductivity. 

A model success

This type of molecular simulation had never been done for metals before, so the researchers had to get creative. They looked to semiconductors for inspiration because previous research had successfully simulated conductivity in these silicon-based materials and some metal oxides. The team adapted these concepts to work with aluminum and simulated what would happen to the metal’s conductivity if individual atoms in its structure were removed or rearranged. These tiny changes added up to big gains in total conductivity.  

The model’s ability to simulate real-world conditions surprised even the team. “We didn’t think that these results would be this close to reality,” said Kappagantula. “This model simulation that’s based on the atomic structure and its different states is so precise—I was like, ‘Wow, that’s right on target.’ It’s very exciting.”  

With a theoretical recipe to alter metal conductivity now clear, the researchers plan to see how much they can increase the conductivity of aluminum in the laboratory to match theory with experimental results. They are also exploring the possibility of increasing the conductivity of other metals using the same simulations. 

A recipe for next-generation metals

The research team expects that more conductive aluminum would have far-reaching implications—any application that uses electricity or copper could benefit from the development of affordable, lightweight, ultra-conductive aluminum. 

This research was supported through the Hydro-Innovation and Technology-ENA and the National Science Foundation. Development efforts to apply these results to specific energy applications are sponsored by the Department of Energy’s Advanced Manufacturing and Vehicle Technologies Offices.