Iron-Air Utility Scale Stationary Battery at 1/10th the Cost of Lithium Ion

Form Energy has an iron-air battery technology that is optimized to store electricity for 100 hours at system costs competitive with legacy power plants. It is a cost-effective, multi-day energy storage systems. They use new iron-air battery chemistry for their irst commercial product and have a $200 million Series D financing round led by ArcelorMittal’s XCarb innovation fund.

Nextbigfuture covered Form Energy back in 2018.

They have 1/10th the cost of lithium-ion.

This is a “Reversible Rust” Battery that could transform energy storage.

They used a membrane repurposed from a zinc-air battery design. This membrane has a lower overpotential. They solve roundtrip efficiency concerns from earlier designs.

The iron-air battery takes in oxygen and then uses it to convert iron inside the battery to rust, later converting it back to iron again. Converting back and forth between iron and rust allows the energy that is stored in the battery to be stored longer than conventional batteries.

The batteries are much too big and heavy for use in small applications (or cars)—each battery is approximately the size of a washing machine. Instead, they are meant to be hooked together in massive grids capable of storing enormous amounts of electricity for days at a time. Cells are stacked inside of a water-based, non-flammable electrolyte, which the company claims is similar to that used in standard AA batteries—the cells are made of iron and air electrodes.

Thousands of the batteries could be used to store huge amounts of power—they suggest that a grid covering approximately one acre using their low-density batteries could provide power for a one-megawatt system. The high-density version, would be triple that.

These new battery technologies are more cost-effective for utility scale storage applications compared to current storage technologies. Lithium ion batteries typically cost up to $80 per kw/hour of storage. The new battery costs under $6 per kw/hour in its most basic form, and approximately $20 per kw/hour when outfitted as part of a total system—a price point. Bill Gates and Jeff Bezos have invested. They have already forged deals with some utilities, such as Great River Energy in Minnesota.