The influence of CO on the current density distribution of high temperature polymer electrolyte membrane fuel cells

摘要

In this work, the effect of stepping the CO amount at the anode gas feed from 0.0 % to 1.5 % or 3.0 % on the feed of a high temperature polymer electrolyte membrane fuel cells (HT-PEMFC) is addressed using a PBI/ H3PO4 based MEA. The poisoning was assessed at 160 oC based on the transient behavior of the fuel cell voltage and current density distribution. The current density distribution at similar voltage and global current density were also compared for pure hydrogen and CO balanced hydrogen. Furthermore, the I-V and power density curves were obtained. Two different cell anodes were used to obtain the current density distribution, 1) a metal segmented flow field and 2) a non-segmented graphite flow field where it was applied a printed circuit board as segmented current collector. The presence of CO caused a performance loss, which was aggravated for higher CO concentrations and higher global current densities. The current density distributions obtained with metal segmented flow field showed that the use of CO balanced hydrogen originated a spatial distribution of CO at the anode, which was more evident for higher CO concentrations and global current densities. On the other hand, no significant change on the current density distribution was observed with the graphite flow field.