Consider that for a Moments, wires, a pervasive technology that is very easy to forget. Millions of tons of fine metal wire wrapped inside our devices, wrapped around our walls, and strung along our streets, brought electrification to the world. But their work is benign and so natural that it doesn’t feel like technology at all. Wires move electrons simply because of what metals do when they supply current to them: they conduct electricity.
But there is always room for improvement. Metals conduct electricity because they contain free electrons that are not bound to any particular atom. The more electrons that flow, the faster they go, and the more conductive the metal is. So to improve this conductivity—critical for conserving energy produced in power plants or stored in batteries—materials scientists are often looking for more perfect arrangements of atoms. Their main goal is purity – removing any foreign material or blemishes that disrupt the flow. The more gold a hunk of gold is, and the more copper the wire is, the better it conducts electricity. Anything else will get in your way.
“If you want something that’s really highly conductive, you have to be pure,” says Keerti Kappagantula, a materials scientist at Pacific Northwest National Laboratory. That’s why she considers her research rather “weird.”Her goal is to make metals more conductive less pure. She will use metals such as aluminum and add additives such as graphene or carbon nanotubes to make alloys. Doing it the right way, Kappagantula found, the extra material has a strange effect: It can push the metal past its theoretical conductivity limit.
The key, in this case, is to create aluminum that can compete with copper in electronic devices — a metal that is almost twice as conductive but also about twice as expensive. Aluminum has its benefits: it is much lighter than copper. As the most abundant metal in the Earth’s crust — a thousand times more than copper — it’s also cheaper and easier to mine.
On the other hand, copper is becoming more difficult to source as the world transitions to green energy. While long ubiquitous in wires and motors, demand for it is surging. Electric vehicles use about four times as much copper as conventional cars, and more copper will be required for the electrical components of renewable energy power plants and the wires that connect them to the grid. Analysts at energy-focused research firm Wood Mackenzie estimate that offshore wind farms will require 5.5 megatons of metal within 10 years, mainly for large cable systems within generators and for transporting the electrons produced by the turbines to shore. Copper prices have soared in recent years, and analysts expect a growing shortage of copper. Goldman Sachs recently declared it the “new oil.”
Some companies have already swapped it out for aluminum where possible. Everything from air conditioners to auto parts has seen a multi-billion dollar transformation in recent years. High-voltage power lines already use aluminum wires because they are cheap and lightweight and can be strung over longer distances. Aluminum is usually the purest and most conductive form.