A 140-Years-Old Battery Technology Might Change Everything We Know About Energy Storage

source: autoevolution.com  |  image: pixabay.com

Li-Ion batteries power everything today, from tiny gadgets to cars and even airplanes. But for all the benefits that Li-Ion batteries bring to the table, there are tons of problems. These range from the costly and difficult to source materials to safety problems and the damage they cause to the environment. Scientists think they found an alternative that could change everything we know about batteries.

The idea comes from a 140-year-old battery technology, known as the metal-air type. The first metal-air batteries were designed in 1878, using atmospheric oxygen as a cathode (electron receiver) and a metal anode (electron giver). The anode can be made out of cheap and abundantly-available metals such as aluminum, zinc, or iron.

The zinc-air batteries were the first to see wide adoption in hearing-aid devices. Theoretically, metal-air batteries have a higher energy density than Li-Ion batteries, while at the same time being inexpensive, thanks to the ubiquity of the metals used. Their main problem is that they were impractical to recharge because of them rusting.

More specifically, the battery can corrode quickly once the flow of oxygen has started, even when left unused. This is why we now have metal-air batteries, but they are not rechargeable. A team of researchers from the Massachusetts Institute of Technology (MIT) announced a breakthrough in iron-air battery technology that allows the cells to be rechargeable. The process is called “reverse rusting” and is said to allow efficiently store and release energy.

When you reverse the electrical current on the battery, it un-rusts the battery. Depending on whether the battery is discharging or charging, the electrons are either taken away from or added to the iron,” explains Yet-Ming Chiang, an electrochemistry professor at the Massachusetts Institute of Technology, for Popular Science. He claims that the battery can deliver 100 hours of clean electricity at a price of only $20/kWh, ten times cheaper than lithium-ion batteries, which cost up to $200/kWh.

The new iron-air battery might not be suitable for use in electric vehicles anytime soon, because the iron is a lot heavier than lithium. But it could prove exceptionally efficient for stationary energy storage. Chiang and his colleagues have founded the start-up Form Energy to develop a low-cost iron-air battery by 2024. This should provide multi-day storage for renewable energy.