Production of compound-based PEM fuel cell bipolar plates with reduced cycle time using a novel compression moulding concept

The production of compound-based bipolar plates for use in PEM fuel cells using injection moulding allows only limited filling levels. Improved electrical properties require a higher content of graphite and conductive carbon black. Processing of this pulverized feedstock requires compression moulding for manufacturing. So far, this process is only automated to a limited extent and associated with long process times. As part of a funded research project a highly automated process with reduced cycle times for compression moulding is implemented, enabled by a mould with reduced steel masses using ultra-high-performance concrete and inductive heating. Properties and application limits of the used materials and components are investigated and optimized in this work. With that, cycle times are already reduced by 45 %, with prospect of further optimization. The moulding accuracy of the flow-field structures and the properties of the plates are comparable with those from conventional processes. • Novel hybrid compression moulding concept, using concrete and induction heating. • Content of electric conductive additive in compound for bipolar plates is increased. • Additiv manufacturing enhances strength of coils, using internal structures. • Cycle time reduction for compression moulding at about 45 %.