In the already completed research project UltraPress (03VNE1022D), which was funded within the framework of the BMBF’s KMU-NetC funding initiative, the foundations for a novel innovative compression molding process using a tool made of ultra-high-performance concrete (UHPC) and inductive heating for the production of graphite-based bipolar plates for PEM fuel cells were created and its suitability was demonstrated.

Inductive heating eliminates the usual bottlenecks of compression molding, such as long cycle times and high energy consumption due to the required heating and cooling phases. The already developed compression molding process with a molding tool made of special concrete does not have these disadvantages. With this, graphite bipolar plates can be compression molded within a few seconds.

Due to the enormous time and cost savings, this manufacturing process is to be further developed and transferred to a series production process over the next three years in the follow-up project “Ultrapress2”, which has now been started. To this end, the companies Proton Motor Fuel Cell GmbH, Boyke Technology GmbH, Eisenhuth GmbH & Co. KG, Runkel Fertigteilbau GmbH, Eldec Induction GmbH, MC-Bauchemie Müller GmbH & Co. KG, the Institute for Design and Manufacturing in Precision Engineering at the University of Stuttgart and the Centre for Fuel Cell Technology have joined efforts funded by the BMWK (project 03EN5010D).

The innovative approach here is inductive heating and the use of ultra-high-strength concrete as a compression molding tool. This combination enables fast heating times, whereby only a minimum of steel mass is specifically heated. Furthermore, a significant improvement in product quality can also be achieved, to which the more homogeneous heating of the compound material caused by induction as well as the targeted control of solidification contribute.

The target for the bipolar plate is the NT-PEM bipolar plate design PM200 and PM400 from the company Proton Motor, which, as the end user, is investigating the final qualifications of the plates in stack tests.

Within the project, the ZBT will expand its expertise and machinery in the field of hydraulic presses and compression molding. For this purpose, a fully automatic laboratory press will be procured, which will enable compression molding of bipolar plates and small-step monitoring and optimisation of the process. In addition to further reducing process times and scaling up the compression molding tools, the aim of the project is to implement the newly developed inductive compression molding process in a demonstration plant for the automated and pre-series production of bipolar plates.

• • Proton Motor Fuel Cell GmbH
  • Boyke Press Technology GmbH
  • Institut für Konstruktion und Fertigung in der Feinwerktechnik – IKFF
  • Eisenhuth GmbH & Co. KG
  • Zentrum für BrennstoffzellenTechnik GmbH
    • Department New Materials and Technologies
    • Department Fuel Cells and Stacks

  • Runkel Fertigteilbau GmbH
  • MC-Bauchemie Müller GmbH & Co. KG
  • Eldec Induction GmbH