The lung of the fuel cell
4 April 2003 - 4 April 2003
Germany
However environment-friendly fuel cells may be, like any other energy source their success on the market depends not only on their area of application but also, more particularly, on their price. A number of technological hurdles will have to be overcome before the various systems can be mass-produced cost-effectively. Bipolar plates, which currently account for up to half of the total cost of PEM fuel cells, are a prime example. The gases supplied to and from a fuel cell flow through the stamped or milled channels on these plates as in a lung. Stacked on top of each other, their second job is to ensure electrical contact between adjacent cells in the same way as batteries connected in series. This means that only conductive materials can be used. Steels and many other metals are, however, suitable only to a limited extent because at temperatures of up to 100 °C they cannot withstand the corrosive conditions for an adequate length of time. Graphite has the disadvantage that each part has to be machined individually (and therefore expensively) using metal-cutting processes. Hot pressing and injection molding techniques, as used in plastics processing, provide an alternative approach.
Imagine having to cook waffles using dough mixed from a kilogram of flour and two eggs!, Axel Kauffmann from the Fraunhofer Institute for Chemical Technology ICT strains the culinary art to explain the thinking behind the new technique. Even if we used graphite powder or conductive carbon black and thermoplastic materials as binding agents the result is just as crumbly. Increasing the proportion of polymers makes the mixture thinner and easier to process but at the same time its electrical conductivity decreases. He and his colleagues have overcome this and many other problems. It is now possible to manufacture bipolar plates cost-effectively in series production. Although their conductivity is not as good as that of compact graphite, it is adequate for small fuel cells.
Seven Fraunhofer Institutes are involved in the Fraunhofer Micro Fuel Cell Initiative, which is represented at the Hanover Fair in Hall 13, Stand G 72. In addition to the technologies being studied and developed by our colleagues at the ICT, lots of others come into consideration for the production of bipolar plates, emphasizes Reiner Borsdorf from the Fraunhofer Institute for Production Technology IPT. Which one will prove to be the most suitable in the end depends entirely on the design and the material. The IPT is the right address for selection and configuration of the production and assembly steps.,Contact:,Axel Kauffmann,Phone: +49 7 21 / 46 40-4 25,Fax: +49 7 21 / 46 40-1 11,E-mail: kauf@ict.fraunhofer.de<br>Fraunhofer-Institut fur Chemische Technologie ICT(opens in new window),Joseph-von-Fraunhofer-Strasse 7,76327 Pfinztal / Berghausen, Germany<br>Reiner Borsdorf,Phone: +49 2 41 / 89 04-1 32,Fax: +49 2 41 / 89 04-61 32,E-mail: r.borsdorf@ipt.fraunhofer.de<br>Fraunhofer-Institut fur Produktionstechnologie IPT(opens in new window),Steinbachstrasse 17,52074 Aachen, Germany,
Imagine having to cook waffles using dough mixed from a kilogram of flour and two eggs!, Axel Kauffmann from the Fraunhofer Institute for Chemical Technology ICT strains the culinary art to explain the thinking behind the new technique. Even if we used graphite powder or conductive carbon black and thermoplastic materials as binding agents the result is just as crumbly. Increasing the proportion of polymers makes the mixture thinner and easier to process but at the same time its electrical conductivity decreases. He and his colleagues have overcome this and many other problems. It is now possible to manufacture bipolar plates cost-effectively in series production. Although their conductivity is not as good as that of compact graphite, it is adequate for small fuel cells.
Seven Fraunhofer Institutes are involved in the Fraunhofer Micro Fuel Cell Initiative, which is represented at the Hanover Fair in Hall 13, Stand G 72. In addition to the technologies being studied and developed by our colleagues at the ICT, lots of others come into consideration for the production of bipolar plates, emphasizes Reiner Borsdorf from the Fraunhofer Institute for Production Technology IPT. Which one will prove to be the most suitable in the end depends entirely on the design and the material. The IPT is the right address for selection and configuration of the production and assembly steps.,Contact:,Axel Kauffmann,Phone: +49 7 21 / 46 40-4 25,Fax: +49 7 21 / 46 40-1 11,E-mail: kauf@ict.fraunhofer.de<br>Fraunhofer-Institut fur Chemische Technologie ICT(opens in new window),Joseph-von-Fraunhofer-Strasse 7,76327 Pfinztal / Berghausen, Germany<br>Reiner Borsdorf,Phone: +49 2 41 / 89 04-1 32,Fax: +49 2 41 / 89 04-61 32,E-mail: r.borsdorf@ipt.fraunhofer.de<br>Fraunhofer-Institut fur Produktionstechnologie IPT(opens in new window),Steinbachstrasse 17,52074 Aachen, Germany,