Massachusetts start-up Form Energy has created an iron-based battery that can run for 150 hours. The battery draws in oxygen when it is discharged and gives it back when it is charged.
At the heart of the work is a chemical reaction in which iron turns into rust and is reduced. Batteries use a redox reaction using iron, when in the presence of oxygen, iron turns into rust or oxidizes and releases energy during a chemical reaction, and during reduction releases oxygen and reduces iron from oxide, thereby accumulating energy.
Such a battery is charged within a few days, but gives energy from 100 to 150 hours.
According to the heads of the startup, one battery pack will combine 20 cells. The cost per 1 kWh will be $ 6 for each cell and no more than $ 20 per 1 kWh for an assembled unit. This is 4 to 10 times cheaper than lithium batteries.
The new battery will be relevant for stationary energy storage systems, and will also help the introduction of renewable energy.