(Stuttgart) – Scientists and companies are looking for ways to reduce waste in the production of metallic bipolar plates and to enable the large quantities required for the energy transition to be made available. Bipolar plates (BPP) are a key component for fuel cells. Depending on the type and size, 300 to 600 BPP are installed in the systems.
A fuel cell consists of numerous membrane electrode units (MEA) arranged in a stack, in which the conversion of chemical to electrical energy takes place. Bipolar plates lie between these units and take on the function of supplying the required reaction gases and removing the resulting water, according to the University of Stuttgart.
Trend towards metallic BPP
BPP made of graphite dominated the market for a long time, but the trend is towards metallic BPP for economic reasons and due to their higher conductivity. “To produce these, forming technology processes are used, which enable lower costs and significantly faster cycle times compared to metal-cutting manufacturing processes,” explain the scientists. However, when forming sheet metal, even slightly fluctuating process parameters could lead to forming errors such as tears, folds or bulges, which make assembly of the cell stacks more difficult.
As part of the “AKS-Bipolar” project, the Stuttgart researchers are now looking for solutions to the manufacturing problems together with the Fraunhofer Institute for Physical Measurement Technology in Freiburg and the companies Thyssenkrupp System Engineering and Chemical Works Kluthe. The quality of metallic BPP is checked downstream in cost- and time-intensive random tests. The researchers in the “AKS-Bipolar” project (active process control in the series production of high-precision embossed bipolar plates) therefore also want to develop “an overall system for active process control and quality assurance that integrates full-surface 3D measurement technology directly into the production line of the components and all process stages in one “Overall simulation depicts”.
The project has a total volume of around 1,43 million euros and is funded by the German Research Foundation DFG and the Fraunhofer Society.
Photos
Test facility at the Institute for Forming Technology at the University of Stuttgart. In the background, institute director Mathias Liewald. © Max Kovalenko, University of Stuttgart
