Cummins Invests $24M In Flow Battery Leader Voltstorage

Cummins has invested $24 million in Germany-based VoltStorage, a developer of stationary flow batteries. The company says that it has the largest fleet of operating flow batteries in the world.
Headquartered in Munich, VoltStorage was founded in 2016 by Jakob Bitner, Michael Peither and Felix Kiefl. VoltStorage develops and produces commercial storage systems based on the particularly ecological vanadium redox flow technology for commercial and agricultural enterprises. In addition, the international research and development team is working on the low-cost iron-salt battery, the properties of which make it particularly suitable for ensuring base load capability for wind and solar farms.
With the development of the iron-salt technology, the company is setting new standards in the field of long-duration energy storage, offering wind and solar farms a highly cost-effective and resource-saving option for ensuring base load capability.
According to VoltStorage, Cummins’ investment will go toward developing larger-scale redox flow storage systems for commercial and agricultural enterprises and residential neighborhoods. In addition, product development of the iron-salt technology will be accelerated towards commercialization.
Iron-Salt technology is a highly temperature-resistant battery technology that can be used worldwide, even in climatically challenging regions. In addition, the storage system can be connected to existing infrastructures in a space-saving and decentralized manner, which additionally ensures the self-sufficient functionality of the storage solution and increases reliability.
The iron-salt redox flow battery unit is based on two battery half-cells through which liquid electrolyte is pumped in independent cycles. The half-cells are separated by a membrane and together form the full battery cell. The electrolyte is enriched with iron chloride.
During charging or discharging, ions and electrons are transferred between the two half-cells, storing, or releasing energy in the electrolyte. In the uncharged state, both cells have identical oxidation levels; charging leads to reducing the electrolyte in one half-cell and oxidizing electrolyte in the other. Within the negative half-cell, the iron in the electrolyte is deposited as metal on the electrode.
The battery capacity is dependent on the iron deposition: an increasing amount of iron deposition leads to a higher capacity. The reaction is fully reversible, and iron is re-dissolved in the electrolyte during discharging.