MoBs-RFB
The energy transition is driving the electrification of the heating and mobility sector and increasing the electrical energy demand of private households through heat pumps and electric vehicles. Photovoltaic systems can cover most of this demand, but require the use of battery storage systems. Vanadium redox flow batteries (VRFB) are a sustainable alternative to the widespread lithium-ion technology. These can be operated more efficiently and economically with highly conductive cation exchange membranes, although their increased crossover material flow requires control of the state of charge and state of health (SoC / SoH). For this purpose, a modified open-circuit voltage (OCP) cell is coupled with an observer model algorithm for independent measurement of the electrolyte equilibrium potentials. Based on the SoC and SoH, an operating strategy is developed in which the electrical polarization of the battery is regularly reversed in order to compensate for the concentration difference caused by the crossover material flow in the long term and to keep the material composition of both electrolyte sides stable without maintenance. After testing in laboratory systems, the OCP cell, the observer algorithm and the operating strategy are combined in a 2kW-6kWh home storage system and their stable and more economical function is demonstrated. The technical improvements promote the widespread use of VRFB technology as battery storage, also in the private sector.
General information on the project:
Duration: 01.09.2024 - 31.08.2027
Project management: Prof. Dr.-Ing. Oliver Bohlen
Project team member: Kieran Oswald
Project funding: Bayerische Forschungsstiftung
Project partner: Kermi GmbH
Institutions:
