A global team of researchers led by the Massachusetts Institute of Technology has developed an alternative battery technology that uses commonplace materials like aluminum and sulfur instead of lithium and other rare metals, according to a scientific paper published last week in the journal Nature.
The aluminum-sulfur batteries could be deployed for a fraction of the cost of lithium-ion batteries, and because they cannot catch fire, they do not come with the same need for cooling systems when used in large numbers, according to MIT Professor Donald Sadoway, one of the researchers behind the project.
Sadoway, who has since left MIT to found Avanti, a startup company dedicated to commercializing the battery, said it could still be several years before their product is ready for commercial applications.
New research from MIT suggests aluminum-based batteries not only have the potential to replace lithium-ion technology for a fraction of the cost – they could even prove superior in some contexts.
Research from the university shows that the performance of the batteries, made with a combination of sulfur, rock salts and aluminum, matched that of lithium-ion batteries across a number of key metrics. However, the aluminum-based batteries could be made for about 1/6 the cost of lithium-ion options, according to the report, and can also charge and discharge much more rapidly.
“It performs virtually identically to lithium-ion,” Sadoway said, “but we demonstrated this can charge far more rapidly than lithium-ion – charging in minutes, not tens of minutes.”
This rapid charging capacity could make aluminum-based batteries attractive to automotive applications, where consumers are looking to relieve their range anxiety with the ability to recharge rapidly, in a fashion similar to combustion engines. But Sadoway said he doesn’t plan to target EVs as his first potential market for the new battery technology – the profit margins are simply too narrow there, he said. Rather, he plans to initially offer small-scale, stationary storage options suitable to a single residence or small business.
Because none of the battery’s components can burn, Sadoway said, they may have some potential advantages in stationary applications as well. Lithium-ion batteries, when stacked close together for large-scale applications, must be cooled in order to prevent overheating and fire. These cooling systems add to the cost of the installation, and eat up some of its energy as well. Aluminum-based batteries are free of these constraints, he said.
But the aluminum-based batteries may not be suitable for hand-held applications such as smart phones, because the operating temperature of the battery – just below the boiling point of water – is a little too high to handle comfortably.
“At a temperature comfortable enough for you or me to hold this thing, the salt is frozen and the battery won’t operate,” Sadoway said. “Lithium-ion is a terrific technology, but let’s not forget lithium-ion was invented for hand-held devices, so that’s where it’s done the most — mobile phones, laptop computers. It was never intended to go into cars, and certainly never intended to go into massive stationary sources.”
Regardless of which applications take off first, Sadoway said it will still be some years yet before aluminum-based batteries are ready for commercial applications. His new startup, Avanti, will first have to increase the size and the capacity of the batteries, test their long-term durability, and develop manufacturing processes for production at scale.