Abstract
Phosphoric acid is utilized as electrolyte in high temperature polymer electrolyte (HT-PEM) fuel cells to guarantee proton conduction. Loss of electrolyte may be identified as one of the main degradation aspects. The data presented in this paper focus on a better understanding of the degradation paths caused by acid loss from the membrane-electrode-assembly. Therefore this investigation examined the phosphoric acid distribution in an experimental fuel cell setup. Two operational strategies with long term tests under constant load conditions at 0.3 A/cm² and load cycling tests between high current densities of 0.6 A/cm² and 1.0 A/cm² have been performed. The detection of acid content in the various fuel cell components in combination with imaging methods for the identification of changes in surface structure on the bipolar plates provide good instruments to investigate the influences of acid loss during fuel cell operation.