Campus Schwarzwald. (c) Rainer Bez / Fraunhofer IPA
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In the “H2FastCell” research project, a research team from Fraunhofer IPA and the Black Forest Campus is working with an industrial consortium to develop a robotic cell for the automated high-speed assembly of fuel cell stacks. In doing so, they are laying the foundation for the industrial mass production of this emission-free technology.

Hydrogen will play an important role as an energy carrier. It can be produced from renewable energies in electrolyzers in a CO2-neutral way and then converted into electrical energy in fuel cells. Particularly in freight transport, fuel cells can be advantageous compared to battery-electric vehicles. But there are also many future areas of application for fuel cells in the stationary sector.

Scaling effects

In the production of fuel cells, efficient cycle times and absolute precision are crucial. The major goal is to reduce manufacturing costs to make the use of this technology more economical. But this can only be achieved through upscaling, which requires fully automated plants with high capacities. At the moment, this type of production plant is not yet available on the market. The design of the components must also be optimized to find a design suitable for automation. That’s why it makes sense to start looking now for ways to manufacture them in an automated way suitable for mass production.

This is precisely what a research team from the Fraunhofer Institute for Manufacturing Engineering and Automation IPA and the Center for Digitalization, Leadership and Sustainability Black Forest (Black Forest Campus) in Germany has set out to do in the “H2FastCell” project. Together with teams from five companies, the scientists want to develop a robotic cell by 2023 that assembles the individual layers of a fuel cell in seconds and with absolute precision.

Finished in just 13 minutes

A fuel cell stack consists of stacked layers of bipolar plates through which hydrogen and oxygen are introduced, and membrane electrode units in which the two chemical elements react with each other. Because this reaction only produces a maximum voltage of one volt, about 400 fuel cells must be stacked on top of each other for a fuel cell engine to power a truck, for example. Precision is a must. Any deviation – even in the micrometer range – can reduce the performance of the fuel cell system.

The assembly robot will take over the stacking of bipolar plates and membrane electrode units in alternation in the H2FastCell research project. It will scan the individual layers as it grips them. Since it assembles several stacks in parallel, it can spontaneously assign a layer to the stack to which the dimensions fit best. Decreased performance is thus avoided before it even occurs.

All this is supposed to happen so fast that it will be difficult for humans to follow the individual assembly steps with the naked eye: one second per layer. A stack composed of 400 individual fuel cells would therefore be finished after only about 13 minutes. Manually, this would take many times longer.

Competitive

“If the throughput of the stacks is increased like this, it will lay the foundation for the industrial mass production of fuel cells. Prices would drop and the use of fuel cells in mobile heavy-duty applications would finally become competitive,” says Friedrich-Wilhelm Speckmann of the Center for Digitized Battery Cell Production at Fraunhofer IPA. He and Erwin Gross from the Corporate Strategy and Development department at Fraunhofer IPA are leading the H2FastCell research project.

By summer 2023, the research team aims to have set up a demonstrator stacking facility for automated fuel cell assembly at the Black Forest Campus in Freudenstadt. This facility will be available to companies for further trials, feasibility studies and validations.