The most durable storage technology for your home.
Vanadium redox flow technology (VRF) has been successfully used for years as a large-scale storage technology for photovoltaic and wind farms. For the first time, VoltStorage takes the world’s most durable storage technology into your own home and offers a pioneering alternative to lithium-ion storage – “Made in Germany”.
Operating principle of the vanadium redox flow storage technology.
Positively charged electrolyte tank
In the uncharged state, the positive electrolyte circuit contains vanadium ions with an oxidation state +4. In this state the electrolyte takes on a blue colour. Once it is supplied with the power that is to be stored, the vanadium ions oxidize and assume the oxidation state +5. When the storage system is fully charged, the positively charged electrolyte circuit only contains vanadium +5. The electrolyte then shows a yellowish colour.
Negatively charged electrolyte
In the uncharged state, the negative electrolyte circuit contains vanadium ions with an oxidation level of +3. This causes the electrolyte to take on a blue-green colour. Once it is supplied with the power that is to be stored, the vanadium ions reduce and assume the oxidation state +2. When the storage system is fully charged, the negatively charged electrolyte circuit only contains vanadium +2. The electrolyte then has a purple colour.
The positively and negatively charged electrolyte is fed into the battery to initiate charging and discharging processes. The membrane keeps both electrolyte liquids separate to ensure the efficiency of the battery system. However, the membrane is ion-permeable, so that during charging and discharging the ions cross the membrane to complete the electric circuit. This allows for electrical energy to be stored through a redox reaction, which converts electrical into chemical energy.
The pumping system is responsible for feeding the vanadium electrolyte into the battery. The internal battery management ensures that the quiet pumping system is only activated whenever necessary. This guarantees that the pumps are used efficiently.