Affiliation:
1. Tongji University, School of Automotive Studies
Abstract
<div class="section abstract"><div class="htmlview paragraph">The performance and lifetime of proton exchange membrane fuel cells (PEMFC) are
affected by impurities in the gas stream. The concentration of ammonia in the
air can exceed 1ppm in a specific area, which is a potential factor in the
degradation of PEMFC performance and lifetime. Investigating the mechanism and
concentration threshold of cathode ammonia poisoning PEMFC is the prerequisite
for preventing catalyst ammonia poisoning. In this work, the effect of
250ppb~5ppm transient contamination on PEMFC performance and impedance is
studied. The results show that the attenuation performance caused by ammonia is
attributed to the increase of impedance, which is mainly reflected in the mass
transmission resistance, followed by the cathode activation resistance, and has
little effect on the charge transfer resistance. The performance is somewhat
recovered after the polarization curve testing, which is related to the voltage
change and the increase in water generated during the high current density.
Through the comprehensive analysis of the voltage and EIS, it is concluded that
the transient tolerance concentration threshold of PEMFC to ammonia is
500ppb.</div></div>