Redox flow technology for large scale battery energy storage systems




Our technology embodies sustainability. It is a crucial step towards a decarbonised world. By 2040, the globe is projected to produce 160 000 TW of energy from renewable sources. With the majority of these sources providing power intermittently, sustainable and reliable and long duration energy storage is imperative. Redox One’s solutions precisely offer that.

Daily renewable energy generation does not follow demand.

Ensuring consistent energy supply using chromium iron batteries
Tech battery

World needs up to 140 TWh of long duration energy storage to meet net-zero goals by 2040

As the world increasingly adopts renewable energy sources (ie solar and wind), the widespread adoption of Long Duration Energy Storage (LDES) from 4 to 12 hours is key to manage intermittencies and the temporal differences in peak supply and demand.

By 2040 it is estimated the world will require 160 TWh of storage capacity per year*.

Safe, cost-effective, reliable, sustainable, and scalable, Redox One's Iron-Chromium Redox Flow Batteries are poised to power a decarbonised future in a market growing to $3 trillion by 2040.

Redox One – Switched On. Always.

Electrolyte diagram for chromium iron batteries used for large scale power storage



Our technology is not new; it has been refined and proven over time. In fact, NASA first pioneered Iron-Chromium as the first Redox Flow Battery (RFB) in the 1960s. Since then, it has matured, refined, and amassed numerous proof points, including many successful deployments. Our Iron-Chromium Redox Flow Batteries (Fe-Cr RFBs) result from decades of innovation, research, development, and optimisation.

Why Iron-Chromium Redox Flow Batteries for Long Duration Energy Storage?

Safe, cost-effective, reliable, abundant, sustainable, secured.

Redox One - Switched On. Always.

high-temperature stable: 60°C operating temperature, aqueous solution (no fire danger or explosive substances).

Proprietary and patented electrolyte manufacturing processes directly from the ore with unmatched affordability – costs 80% lower than Vanadium electrolytes.

20,000+ cycle-life with minimal degradation and decades of use.

Iron is the 4th most abundant mineral in the earth’s crust and Chromium is the 8th most produced mineral on the planet. Our supply chain is not dependent on “critical raw materials” like Li-Ion batteries or Vanadium RFBs.

The electrolyte is 100% reusable and recyclable.

Redox One has exclusive and direct access to nearly unlimited raw materials through our partner Tharisa, supporting a stable supply of electrolyte for decades to come.

Most Resilient Long Duration Energy Storage Solution

Li-Ion has significant capacity fade over time and needs full replacement after ~10 years.

Iron-Chromium Redox Flow Batteries have a virtually no capacity decay and limitless cycle and calendar life.

Redox Flow battery installation in California storing solar energy for continuous operation
Assumption: 1MWh DC capacity installed, two cycles per day, 100% DoD per cycle, capacity decay rate for Li-Ion batteries of around 1% per 100 cycles

How they work

Both electrolyte tanks contain equal concentrations of Iron (Fe) and Chromium (Cr).


Like pumping water through a filter, direct access to electrolyte ensures accurate State of Heath and State of Charge.


Can track load, increase or decrease output, go from charging to discharging in milliseconds.


Other flow batteries use highly sensitive ionic membranes, instead Redox One uses a micro porousseparator at about 0.5% of the cost and significantly more reliable.

Our electrolyte is made from earth abundant Iron and Chromium diluted in a weak Hydrochloric acid.

Solar array at redox flow battery installation to capture sustainable energy and store it for future use

-Fe+2 oxidized to Fe+3
-Cr+3 reduced to Cr+2 (Accepts electron and gains electric potential energy).

-Fe+3 reduced to Fe+2
-Cr+2 oxidized to Cr+3 (Gives electron and releases electric potential energy).