Cooking up a conductive alternative to copper with aluminum
In the world of electricity, copper is king for now. That could change with new research from Pacific Northwest National Laboratory (PNNL) that offers a recipe for increasing aluminum’s conductivity, making it economically competitive with copper. This research opens the door to experiments that – if fully realized – could lead to an ultraconductive aluminum alternative to copper that would be useful in markets beyond transmission lines and revolutionize vehicles, 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 huge difference because more conductive aluminum is lighter, cheaper, and more abundant,” says Keerti Kappagantula, PNNL materials scientist and co-author of the study. “That’s the big problem we’re trying to solve.”
Copper vs Aluminum
Demand for copper is rapidly exceeding current availability, driving costs up. Copper is a great electrical conductor — it’s used in everything from portable electronics to underwater transmission cables that power the Internet — but there’s no escaping the fact that copper is becoming less available and more expensive. These challenges are only expected to increase with the increasing number of electric vehicles (EVs), which require twice as much copper as traditional vehicles. In addition, copper is heavy, which lowers the efficiency of EVs.
Aluminum is only a third the price and weight of copper, but it is only about 60% conductive. The relatively low conductivity of aluminum can be a limitation in some field applications.
“Conductivity is key because a lighter wire with equivalent conductivity can be used to design lighter motors and other electrical components so that your vehicle can potentially travel longer distances,” Kappagantula said. “Everything from a car’s electronics to power generation to sending it to your home through the electrical grid to charge your car’s battery — anything that runs on electricity — can all make it more efficient.”
Increasing the conductivity of aluminum would be a game-changer.
“For years we thought that metals could no longer be made conductive, but that is not the case,” explains Kappagantula. “If you change the structure of the metal and add the right additives, you can indeed influence its properties.”
To find out how much aluminum conductivity can be increased, Kappangantula and PNNL postdoctoral researcher Aditya Nittala teamed up with Distinguished Professor David Drabold and Ohio University graduate student Kashi Subedi to identify the effects of temperature and structural defects in aluminum conductivity and create an atomic develop a pre-atom recipe to increase conductivity.
A modeling 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 conductivity of the metal if individual atoms in the structure were removed or rearranged. These small changes resulted in large gains in total conductivity.
The model’s ability to simulate real-world conditions surprised even the team. “We didn’t think these results would come so close to reality,” Kappagantula said. “This model simulation based on the atomic structure and its different states is so accurate — I thought, ‘Wow, that’s right on track.’ It’s very exciting.”
Now that a theoretical recipe for changing the conductivity of metal is clear, the researchers plan to see how much they can increase the conductivity of aluminum in the lab to match the theory with experimental results. They are also exploring the possibility of increasing the conductivity of other metals using the same simulations.
The research was published in Physical assessment Band the 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.
“Better” copper means more efficient electric motors
Kashi N. Subedi et al, Electrical conduction processes in aluminum: defects and phonons, Physical assessment B (2022). DOI: 10.1103/PhysRevB.105.104114
Quote: A conductive alternative to cooking copper with aluminum (2022, June 29) retrieved June 29, 2022 from https://phys.org/news/2022-06-cooking-alternative-copper-aluminum.html
This document is copyrighted. Other than fair dealing for personal study or research, nothing may be reproduced without written permission. The content is provided for informational purposes only.