Hydrogen Technology

HOKOME refers to the project of Fraunhofer IWS and four other Fraunhofer institutes to develop highly productive and cost-efficient fabrication processes for fuel cell stacks. Leading international vehicle manufacturers have adopted the use of hydrogen as a CO2-free energy source as an integral part of their strategy. By contrast, the production costs for bipolar plates (BPP) and membrane electrode assemblies (MEA) – the two main components of fuel cell stacks – have been high so far. The research project is addressing this issue and promotes the advanced development of roll-to-roll (R2R) coating technologies suitable for industrial use, as well as the necessary forming and joining processes. These are to replace the discontinuous batch production of individual parts currently in use. The aim is to achieve a significant cost reduction of up to 50 percent. HOKOME thus represents a project that is unique on the market and is of significant interest for sustainable mobile applications, for example in trucks, buses and other vehicles that in particular have to cover long distances.

In the joint project HZwo:FRAME-Tank, Saxon partners from industry and research are developing a ring pressure tank to store hydrogen for mobile energy supply. The carbon fiber reinforced hydrogen tanks consist of two injection-molded half-shells: a laser-transparent, white upper shell and a laser-absorbing, black lower shell. Fraunhofer IWS has developed a suitable laser process for the H₂-tight welding of the half shells. High-quality welding results can be achieved in a time- and material-saving manner on a modern multi-remote system (MuReA), which enables large-area, flexible and fast processing of different materials. The specifically developed joint design ensures that the component tolerances of the large-volume injection molded bodies are optimally bridged, thus ensuring a media-tight weld. Downstream, a toroidal carbon fiber composite pressure tank is generated from the plastic liner using a new ring winding technology. The joint project, which is funded by the ESF-EFRE technology grant from the SAB Sächsische Aufbaubank, thus contributes significantly to an environmentally friendly mobile energy supply in Saxony.

In cooperation with 23 Fraunhofer institutes Fraunhofer IWS participates in the research project H2 D. The scientists are promoting the sustainable and future-proof development of a modern hydrogen economy in Germany and thereby also addressing international dimensions. One of the four key areas of the project focuses on the cost-effective production of hydrogen by means of electrolysis. Fraunhofer IWS scientists support the project by producing bipolar plates (BPP) made of the particularly pure material titanium grade 1 in a powder bed process. Using additive manufacturing, complex and simultaneously filigree column geometries of only a few micrometers can be realized for alternative BPP designs. The suitability of the prototypes for PEM electrolyzers can subsequently be visualized by flow field analyses, which provide information about the uniform distribution of the flow velocity within the BPP. The added value of additive manufacturing is obvious: Prototypes can be produced quickly and without additional tools.