Comparison between electrical and pressure measurements to detect PEM fuel cell flooding

Water flooding is one of the main causes of performance degradation for polymer electrolyte membrane (PEM) fuel cells and its prompt detection is therefore important to guarantee optimal fuel cell operation. This paper aims at comparing the most common methods for flooding diagnosis, which are based on electrical or gas pressure measurements. Some critical issues about them are discussed, highlighting the not straightforward relationships between the different measured physical quantities, that should be taken into account when choosing the most suitable diagnostic approach for each application. A single cell is used for the experimental investigations to allow an easier interpretation of measurement results, although the applicability of the considered methods to fuel cell stacks for commercial applications is also discussed.