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    Vanadium redox flow technology
  • darkblurbg
    The battery with the longest breath

Vanadium redox flow battery

The Vanadium redox flow battery is an efficient way to store electrical energy via redox reactions as chemical energy. In the battery of Volterion / Redox Storage Solutions this process is housed in an extremely compact system that is configurable for every application.


The heart of the battery consists of the so-called stacks. These are stacked cells with a positive and negative electrode in each cell, separated by a membrane that allows ions to pass through and ensures that the electrolytes do not mix. The more cells and the more stacks, the more power (kilowatts) the battery provides.


The energy storage takes place in two tanks with liquid electrolyte based on Vanadium. One contains a positive electrolyte, the other a negative electrolyte. The more electrolyte and the larger the tanks, the bigger the storage capacity (kilowatt hours) of the battery will be.

Loading and unloading

The battery can be charged with sustainably generated electricity from, for example, solar panels. Ions in the positive tank with electrolyte thereby release an electron that can reach the tank with negative electrolyte via the membrane. The electrical energy is stored as chemical energy. The opposite happens when the battery is discharged.


Vanadium is particularly suitable for the redox flow battery. Because there are four different oxidation states of the element (V2 + and V3 + in one tank and V4 + and V5 + in the other tank), the electrolyte does not suffer from contamination by other elements. Moreover, Vanadium is one of the few elements that do not cause corrosion.

Battery design

Our unique battery design is possible thanks to a highly accurate welding method of the stacks. The traditionally used gaskets are therefore unnecessary and this results in robust, leak-free, light and very compact stacks. In terms of cost per kWh, they can easily compete with the best Lithium Ion systems.


Redox flow batteries can be assembled in any configuration. The stacks (capacity) and the tanks with electrolyte (capacity) can both be scaled independently of each other. In one unit, 1 to 6 stacks can handle 2.5 kW to 15 kW of power. The capacity per unit can run from 13kWh to 300 kWh. Multiple units can be easily linked for industrial applications.