It would be a dull month if a new rechargeable battery project didn’t make headlines amid all the excitement surrounding electric cars. This month’s indisputable winner is the lithium-ion battery that replaces cobalt with iron, and—rather surprisingly—works, at least according to the people who came up with the idea.
The potential implications of this invention are huge: Cobalt is enjoying a very strong rally as demand is estimated to skyrocket with the influx of electric cars in the world’s biggest markets, notably China and the United States. So is lithium, but the iron battery is unlikely to have an impact on lithium demand. Also, theoretically, the iron battery could put some battery makers out of business.
The idea of using iron in batteries isn’t new, but so far, attempts to substitute the cheap metal for costlier cobalt and other metals have ended in disaster. Christopher Wolverton, professor of materials science and engineering at Northwestern University, had two problems to solve to make his battery work. First, replace cobalt with iron. Second, trick oxygen into taking part in the reaction that moves the lithium ions from the anode to the cathode and back again as the battery is charged and discharged.
The second challenge was the bigger one. The widespread opinion in science circles is that using oxygen in the reaction taking place in a rechargeable battery makes the concoction inside unstable and oxygen escapes, making the reaction irreversible and the battery non-rechargeable. That’s why Wolverton and his team first made the battery on a computer to see if it would work. Surprisingly for all, it did—and better than the most popular lithium-ion batteries.
The iron battery uses four lithium ions instead of just one like current batteries do. For now, it can only utilize one of these, but there’s potential for making use of all four, considerably increasing the battery’s efficiency.
That’s really exciting, but the official news release is shy on the experimental aspect of the team’s work. There’s mention that there was an author in charge of the experimental work, but all the details about the composition of the battery and the reaction are about the computations the team made. These computations were used to make the physical battery, but the experimental stage of the project is likely at an early stage.
Should further experiments confirm the initial results, this battery has the potential to transform many markets—all that deal in rechargeable devices—from cars to smartphones and wearables. Iron is among the cheapest metals in the world, with a metric ton currently trading for less than $77. To compare, the three-month futures on cobalt on the London Metal Exchange is $75,000 per metric ton. Even that would be enough to make the new battery a hit if its viability is confirmed. The greater durability would also be a welcome bonus.
With a battery like that, the EV revolution could truly take off.
