Manufacturing of Metallic Bipolar Plate Channels by Rolling

Abstract

Producing metallic bipolar plates for Proton Exchange Membrane (PEM) fuel cells by forming is still a topic of research. So far, it has mainly been applied for small batches, but it offers substantial advantages regarding both costs and installation space compared to the established graphite based solutions. One new possibility for an efficient manufacturing process of these metallic bipolar plates is the forming by rolling. For the first time, this technology was used for relevant industrial scale channel geometries. By the use of an experimental rolling mill, 0.1 mm thick 316L (1.4404) stainless steel foils were roll-formed to achieve previously designed channel geometries within one rolling pass. The conducted experiments show promising results regarding the forming accuracy and the shape of the channel cross-sections. With the aim for a proof of concept in the beginning and a subsequent optimization of the process, a numerical simulation was set up prior to the real experiments and later calibrated with the experimental forming results. This calibrated model was used for further improvements of the process with the objective at reducing wrinkles and distortion. The investigation of this new process method for the manufacturing of metallic bipolar plates shows enormous potential and can lead to a more efficient and cheaper production.

Prozessüberwachung mittels maschineninhärenter Sensoren/Transparency improvement in hollow embossing rolling of metallic bipolar plates – Process monitoring by using machine-inherent sensors

“…Eine vielversprechende Umformtechnologie ist das Hohlprägewalzen von metallischen Bipolarhalbplatten (BPHP) für Brennstoffzellenstacks oder von artverwandten Produkten wie Kanalplatten für Wärmetauscher und Elektrodenplatten von Akkumulatoren, mit dem die Produktionsrate deutlich gesteigert und gleichzeitig qualitativ hochwertige Bauteile geliefert werden können [2,6]. Dabei stellen die Entwicklung der Prozesstechnologie [7] sowie die dazugehörige Maschinen- [8] und Überwachungstechnik Gegenstand von Forschungsaktivitäten dar.…”

Improved Performance of Composite Bipolar Plates for PEMFC Modified by Homogeneously Dispersed Multi-Walled Carbon Nanotube Networks Prepared by In Situ Chemical Deposition

“…However, graphite BPs have high processing costs and poor mechanical properties [ 6 ]. Metal BPs have good electrical conductivity, mechanical properties, and easy processing [ 7 ], while the durability of metal BPs in the fuel-cell environment is not good, and the metal ions generated by corrosion will damage the proton exchange membrane and reduce the life of other components of the PEMFC. Therefore, additional costs are often required to prepare corrosion-resistant coatings to increase their durability [ 8 , 9 , 10 , 11 ].…”

Characterization of the Machine Behavior During Hollow Embossing Rolling of Metallic Bipolar Half Plates

“…A promising forming technology is the hollow embossing rolling of complex and thinwalled precision components, which enables to increase the production rate significantly and to deliver high-quality components at the same time [2,6]. In contrast to translational processes, the machine technology for the rolling of thin-walled precision components is not well established and little researched [7,8]. In particular, the knowledge of interdependencies between the rolling process and forming machine is crucial for the rolling process of thinwalled components with demands on dimensional accuracy and shape precision.…”