Comparative study of pinhole detection methods for automotive fuel cell degradation analysis

摘要

Knowledge gained by fuel cell degradation analysis is important for meeting durability targets and thus for the commercialization of polymer electrolyte membrane fuel cells. Herein, the application of the most appropriate characterization method is crucial depending on which degradation mode is dominating. One major failure mode in polymer electrolyte membrane fuel cells is the formation of pinholes in the polymer membrane. In this work, a systematic study of four promising methods for pinhole detection is performed, namely detection via infrared camera, via He-gas detection as well as via pressure drop and hydrogen crossover measurements between anode and cathode. In particular, detection limits as well as influences of the material system and other relevant factors are discussed. Finally, a comparison of the different methods and a recommendation for their practical application is given to optimize detection of membrane defects in the field of failure analysis. The most successful ones are then tested for the analysis of real automotive stacks before and after operation.