Fiber-reinforced bipolar plates for fuel cells

Hydrogen fuel cells are considered to be one approach for substituting fossil fuels in, for example, the automotive industry. Fuel cells consist of multiple bipolar plates which, due to their complex requirements, are made of either coated metals or polymers filled with graphite → graphite polymer compounds. The advantage of the compound bipolar plates is the missing expensive coating which is crucial for the lifetime of metallic bipolar plates. However, the injection molding process and the inferior mechanical properties of the compounds yield in a high wall thickness which increases the volume and decreases the power density of the fuel cell. To oppose these disadvantages, thin compound foils are reinforced with carbon fibers in this project. The fibers are incorporated into the bipolar plate by using press processes while the undulated bipolar plate is formed from the flat compound foil. Furthermore, the materials are characterized for their mechanical properties for a FE simulation to be performed. This simulation is essential for the design of the necessary fiber reinforcement so the bipolar plate can withstand the external and media pressures during the assembly and service life of the fuel cell.

• Zentrum für BrennstoffzellenTechnik GmbH (ZBT)