It‘s quite strange how things often happen in repeating patterns of history. Three ages, copper, bronze and iron were the beginning of metal working, and they transformed human civilization. All batteries use a metal as their active element to store their energy. Llewellyn King shared the thought we are entering the iron age of batteries on April 28, 2024.
Is The Iron Age of Batteries For Real?
Llewellyn King is founder and executive producer of White House Chronicle, and an honorary doctor of engineering from Stevens Institute of Technology. He agrees that batteries are key to optimizing energy from the sun and the wind. But electricity storage is expensive, and the market leader lithium ‘is at the end of a troubled supply chain’.
Iron on the other hand is all around us in steel, and is one of the most abundant materials on earth. All electro-chemical batteries exchange ions between an an oxidation reaction and a reduction reaction inside their cases. A separator keeps these two reactions apart, so they can drive a load through an external circuit.
The oxidation process can only occur in meaningful quantities in certain metals like lithium, and this drives the cost of batteries. But inexpensive iron is an exception to this rule, because it oxidizes (rusts) naturally in the presence of water and air. This potential is sufficiently open-ended for Llewellyn King to enthuse about an iron age of batteries.
How These ‘Iron Age’ Batteries Work
Iron-air battery technology depends on the metal’s natural tendency to rust (that is to oxidize) in the presence of moist air. Hence, such a battery’s main constituents are iron, water and air. In overview terms the iron rusts as it discharges stored energy, but this process reverses out when we recharge the battery again.
An iron-air battery that follows those principles offers fresh hope for a world faced by global warming, that only renewable energy could gradually reverse out. That’s because the energy in iron can slowly discharge over days, not hours. On the downside though, the technology is bulky, and unsuitable for portable applications.
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Earth-Abundant Iron-Based Flow Batteries
