The batteries are based on the chemical element Vanadium and its characteristic of four different stages of oxidation. In each of the four stages Vanadium contains a different electrical charge. Therefore, Vanadium is used as a catalyst to store energy. In order to convert this electrical energy into a chemical compound, it requires two electrodes, called a “stack”.
This stack consists of many cells; each one contains two half-cells that are separated by a membrane. In the half-cells the electrochemical reactions take place as soon as electrolytes flow past the membranes. The reduction or oxidation thus leads to the charging or discharging of the battery.
The stack is connected to two different tanks. One electrolyte tank contains the positive V4+ and V5+ redox couples, the other the negative V2+ and V3+ redox couples. These energy-carrying liquids circulate through the stack by pumps.
Through the use of vanadium and the system of the energy storage, the VRB-Energy Storage is very scalable. Whether for small systems in the kilowatt range or up to large industrial solutions with multi-megawatt. The power of the energy storage can be adjusted by the size of the stack. It defines, how much energy is stored during a certain time. The tank indicates the storage capacity of the VRB-Energy Storage and can easily be extended.