Froning, D.; Maier, W.; Groß, J.; Arlt, T.; Manke, I.; Lehnert, W.: Evaluation of the crack structure of HT-PEFC electrodes from in-situ synchrotron radiographs. International Journal of Hydrogen Energy 39 (2014), p. 9447–9456
10.1016/j.ijhydene.2014.04.059
Open Accesn Version

Abstract:
One of the main goals for improvement of high-temperature polymer electrolyte fuel cells (HT-PEFCs) is the increase of the fuel cell performance under different operating conditions. We investigated the correlation between operating conditions and structural changes in the electrodes by means of in-situ through-plane synchrotron X-ray radiography. From the radiographs it is possible to clearly distinguish between the electrode crack structure beneath the ribs and beneath the channels of the flow field. We present a statistical method to analyze these crack structures. For this purpose a ‘radar’ method was developed in order to obtain the width of the cracks at many different locations and the distribution of crack widths. We found a different behavior of cracks located beneath the ribs and beneath the channels and an influence of the operating conditions on local regions of the crack structure.