The hydrogen and
fuel cell center

Your Contact

Dipl.-Ing. Sebastian Brokamp

group leader stack technology
Department fuel cells and stacks

Tel.: +49-203-7598-4286

Your Contact

Dipl.-Ing. Marco Grundler

group leader compound
Department fuel cells and stacks

Tel.: +49-203-7598-1175

Development of bipolar plates for HT-PEM fuel cells

Bipolar plates constitute one of the main parts of a PEM fuel cell stack. Ideally, these bipolar plates separate the reactant gases and distribute them on each side over the whole active area of the MEA. Furthermore the bipolar plates have to be gas-tight to prevent mixing of the reactant gases. It is required that the bipolar plates are electrically conductive, especially orthogonal to their plane. Thermal conductivity is another important feature that plays a pivotal role in the temperature distribution across each cell and over the entire active area of a fuel cell stack. Yet another characteristic feature required of bipolar plates is their chemical resistance to the operating conditions inside a fuel cell stack. In essence, the bipolar plate material has to endure a steady electrical potential, a low pH environment and temperatures of about 80° C in case of low temperature PEMFCs and up to 200 °C for high temperature PEMFCs.

To meet these demands, ZBT has developed a number of compound mixtures for bipolar plate materials consisting of commercially available thermoplastics, graphite materials and a few other additives, fulfilling the desired properties mentioned as above. Initially, experimental screening of different compound mixtures took place in a kneader and showed that the material is principally suited for extrusion and injection moulding process. Furthermore, the hot pressed prototype bipolar plates have been demonstrated in short stack (HT-PEMFC) assemblies, operating at about 200°C. Flow field and cooling structures are integrated by milling. Geometry of the flow field patterns can be varied to be made adaptable to specific applications of HT PEMFC stacks.

ZBT offers the joint development of materials and plates for different production technologies like hot pressing and injection moulding. The technical infrastructe regarding machines (kneader, extruder, presses, milling, injection moulding) and measuring equipment (material analysis, impedances, leakage, chemical resistivity) as well as the long experience in the development of components for fuel cell stacks give the basis for a funded development.

Last update:  31.03.2020