The assessment of a fuel cell’s “state of health” as well as the prediction of potential cell/stack/system failures requires the application of advanced diagnostic methods during operation. Non-disruptive online diagnostic techniques capable of monitoring cell characteristics under real fuel cell operation conditions are often costly as well as complicated and time consuming to incorporate. Such in-situ measurements are, however, crucial to provide insight into dynamic changes in material and cell characteristics. Supplemented by post-mortem investigations revealing average changes that have taken place over the duration of the test, the state of health may be revealed and the degradation mechanisms unveiled.

Careful interpretation and synthesis of experimental results may form the basis for development of robust degradation mitigation strategies and pin-point the need for new novel and more reliable online and post mortem test methods for further development and improved performance of fuel cell technology.