​PEMFC performance—and certain degradation mechanisms—are closely related to the amount of water present in the components that make up the membrane-electrode assembly (MEA). To make improvements in these two vital areas, researchers must gain a better understanding of the phenomena that cause liquid water to form in MEAs. These phenomena are not very well understood because they are difficult to observe in such small, complex systems.

To find answers, researchers at Liten, CNRS Toulouse, and PSI in Switzerland combined laboratory experiments and modelling techniques. The Liten and CNRS teams used pore network models, which they modified to suit the needs of studying these very unique systems. The theoretical results they obtained on the distribution of liquid water in PEMFCs were compared with images of a fuel cell during operation produced using the large scientific instruments at PSI.

The combined approach was a success. The model was coherent with the MES water concentration profiles observed and with the current density measurements taken using miniaturized sensors developed at Liten.

Ultimately, this research will help in the development of specific processes to enhance materials (such as by optimizing pore ​​​​​size) and improve water-management-related balance. The result will be more efficient fuel cell operation.

*CNRS/IMFT: Institut de Mécanique des Fluides Toulouse, France

**PSI: Paul Scherrer Institute, Switzerland