At the international trade fair and conference Hy-fcell on 8. and On October 9, 2024 in Stuttgart, the Fraunhofer Institute for Laser Technology ILT will show experts from the hydrogen industry how advanced laser technologies are helping to pave the way for the breakthrough of hydrogen technology.
Hydrogen technology as the key to the energy transition is still missing a decisive step: its widespread use. The high costs of expensive materials and complex manufacturing processes for fuel cells and electrolysers are the main factors holding back the longed-for breakthrough. The Fraunhofer Institute for Laser Technology ILT is tackling these challenges and working intensively on developing cost-efficient and scalable solutions. At Hy-fcell 2024 in Stuttgart, the Aachen-based institute will be presenting pioneering innovations in Hall 4, Stand 4E51, which will help to make production processes considerably more economical and sustainable at the same time.
Fraunhofer ILT, Aachen
Drying electrodes by laser: energy efficiency, speed and space savings in fuel cell productio
With the growing demand for fuel cells, it is becoming increasingly important to make production processes more efficient. Drying the wet-applied electrode layers for the membrane electrode assembly (MEA) in the polymer electrolyte membrane (PEM) fuel cell remains a key challenge. Conventionally, this process is carried out in large convection ovens, which consume a lot of energy and take up considerable space in the production hall.
The Fraunhofer ILT has developed a laser-assisted drying technology that addresses these problems. The use of lasers, which expose the electrodes in a defined manner, reduces the drying time from several minutes to just a few seconds. This drastic reduction in drying time enables a significant increase in production speed, particularly in the roll-to-roll process. Furthermore, the laser-based process reduces energy requirements compared to conventional gas-powered continuous ovens.
In addition, the laser system requires significantly less space, which enables a more compact and flexible production line.
“The development of a laser-based roll-to-roll process for the production of membrane electrode units is an important step towards making fuel cell manufacturing processes more efficient. With our laser-assisted drying technology, we are setting a new standard that not only increases production speed, but also optimizes energy efficiency and space utilization,” explains Manuella Guirgues from the Thin Film Processes research group at Fraunhofer ILT.
Fraunhofer ILT, Aachen
Corrosion protection coatings for bipolar plates: increasing efficiency and reducing costs in fuel cell production
Particularly with PEM fuel cells, the aggressive chemical conditions within the fuel cell pose new challenges for production. Protecting the metallic bipolar plates (BPP) from corrosion is not only essential for the service life of the cell, but also for the efficiency of the entire fuel cell stack. Coating the BPPs by means of chemical or physical vapor deposition in vacuum systems causes high costs and slows down production.
The Fraunhofer ILT is working on a process that combines spray coating with laser beam processing to obtain an electrically conductive and corrosion-resistant finish on the metallic bipolar plates – without the need for an energy-intensive vacuum process. This approach not only enables a significant reduction in production costs through the use of cost-effective materials, but also better integration into continuous manufacturing processes. The high scalability of the process helps to efficiently serve the growing market for PEM fuel cells.
Julius Funke from the High Temperature Functionalization research group emphasizes: “Our laser-based method for the production of corrosion protection layers offers an efficient and cost-effective alternative to traditional vacuum processes. It enables faster production and improved scalability, which is crucial to meet the increasing demand for PEM fuel cells.”
Companies work here together with scientists on pioneering solutions – from the optimization of individual processes to the development of new technologies.
Fraunhofer ILT, Aachen
Optimization of fuel cell production through double beam welding and repair of forming tools
Another approach to speeding up the production process elsewhere is double beam welding. This process uses two laser beams simultaneously to weld the metallic bipolar plates, which reduces the cycle time by almost 50 percent without compromising the seam quality. By welding with two beams at one point, the weld pool dynamics can be influenced in a targeted manner, enabling higher welding speeds and avoiding typical defects such as humping.
This enables faster and more efficient production that meets the increasing demands of hydrogen technology. Another aspect in the production of metallic BPPs is the service life of the tool steels used. The tools are susceptible to wear due to their high mechanical loads. The approach is to replace cost-intensive tool steels with structural steels and to apply high-quality wear protection coatings to these using extreme high-speed laser cladding (EHLA).
The coated workpieces have a sliding friction wear resistance that is more than 10 times higher than that of conventional tool steels.
The EHLA process also allows damaged areas of the tools to be repaired, enabling the tools to be adapted and reused. This technology significantly extends the service life of the tools, which in turn reduces production costs and increases sustainability in manufacturing.
The Fraunhofer ILT is developing a number of processes to make the process chain for manufacturing fuel cell components more efficient.
These include high-speed cutting, with which the BPPs are precisely trimmed and media feed holes are cut directly. An innovative approach is the introduction of microstructures into the metallic BPPs by laser, which reduce the electrical contact resistance and displace the water from the contact zone during operation of the fuel cell. The Aachen researchers are also intensively investigating the structuring and welding of compound BPPs and MEAs in order to further automate the production of fuel cells and make it more productive.
Web: ilt .fraunhofer.de
Hy-fcell Stuttgart Hall 4, Stand 4E51
