Fraunhofer UMSICHT developed a 3.2 m²-sized bipolar plate and produced it jointly with SAUERESSIG GmbH + Co. KG. To date, the plate is unique in its size and represents a key technology for large redox flow batteries. The novel bipolar plate material utilized has already been utilized successfully in small redox flow stacks of the Fraunhofer start-up VOLTERION and tested in the field. The large area bipolar plate provides for an output per cell corresponding to approx. 5kW (peak) and/or allows for approx. 350kW (peak) as a stack with 70 cells. A redox flow system with three such stacks (1MW, 10MWh) can provide up to 1,000 households with power for one day. The capacity corresponds to approx. 2,000 typical PV lithium ion batteries (at 5kWh, each). Additional decisive advantages of the new bipolar plate are the low minimum thickness (400-500 µm), the corresponding good conductivity, their flexibility, and the cost-efficient roll-to-roll production method. The objective of Fraunhofer UMSICHT is to not only realize large stacks of its own with this novel bipolar plate, but to also engage with industry partners in a worldwide commercialization.
Fraunhofer UMSICHT | http://www.umsicht.fraunhofer.de/en