LOCAL IN-SITU ANALYSIS OF PEM FUEL CELLS BY IMPEDANCE SPECTROSCOPY AND RAMAN MEASUREMENTS

Kurzfassung

An understanding of the processes inside of low temperature fuel cells on a local scale is required for an effective improvement strategy. For this purpose in situ Raman spectroscopy and local impedance spectroscopy is being developed. The contribution describes the modifications to the cell, and installations of additional devices and the experimental detection systems for integrating both methods into a single cell set up. First results to verify the combined results were carried out and are presented. In the case of the local impedance with segmented cells the additional effort for the simultaneous frequency analysis of all segments is described. The Raman signals of hydrogen, oxygen and water from the channels of the flow field are shown and first measurements of gas composition along the fuel path are analyzed.