Vanadium redox
flow technology

Sustainability, durability and a high level of safety - discover the numerous advantages of this forward-looking storage technology.

Extremely durable, very safe and highly sustainable

Vanadium redox flow technology was developed by the US NASA in the 1970s. With its international team of experts, VoltStorage has now taken resource-saving storage technology to a new level in recent years. The characteristic feature of vanadium redox flow technology is the storage of electrical energy in a vanadium-based electrolyte liquid. This storage technology is very climate-friendly because it does not require any rare materials or conflict raw materials, is fully recyclable, and also has a high level of operational reliability and a long lifetime.

Operating principle


The storage medium is a vanadium-based liquid electrolyte. It is stored in two separate tanks takes on different oxidation states through a redox process. This process makes storing energy possible.


The electrolyte flows through the battery cells in two separate circuits. When the battery is charged, the electrolyte is reduced in the negative half cell and oxidized in the positive half cell. When discharging, this process is reversed again.


A special pump system flows the electrolyte into and through the battery cells. This makes it possible that not all the electrolyte has to be kept in the cells, enabling the decoupling of energy capacity and power. The pumping system is only activated on demand.

Vanadium redox flow battery cell

The cells of a vanadium redox flow battery each consist of two half cells. Each half cell contains a frame with specially designed channels to ensure evenly distributed electrolyte supply to the entire electroactive area. The electroactive area is located in the centre of the half cell and is completely filled with graphite felt. The half cells are separated by an ion exchange membrane. Each battery cell is enclosed by two bipolar plates.


Technological benefits


The vanadium redox flow technology does not require any rare raw materials. The vanadium used in the storage medium is obtained as a by-product of iron production – and thus without overexploitation of nature and the associated impact on our ecosystems.

100% non flammable

Operational safety plays a key role in energy storage. The vanadium redox flow technology offers a decisive advantage in this respect: The vanadium-based electrolyte consists exclusively of non-combustible components, and is mostly pure water.


With the vanadium redox flow technology, we rely on a proven CO2-reducing battery technology. A study by the Technical University of Munich has shown that VRF batteries produced by VoltStorage result in up to 37% less CO2 emissions than the production of comparable lithium batteries.


Storage systems based on redox flow technology can be charged and discharged as often as required without losing storage capacity. Redox flow storage systems are therefore among the longest-lasting storage solutions on the market.

Pioneering innovations

VoltStorage continuously strives to challenge the status quo and set new standards in storage technology. With the development of the resource-saving vanadium redox flow storage technology, VoltStorage is making an important contribution to the development of groundbreaking solutions for Long Duration Batteries. You can find out more about VoltStorage’s current research and development in the Innovation Lab.