Validation of an externally oil-cooled 1 kW_el HT-PEMFC stack operating at various experimental conditions

The performance of 1 kW_el 48-cell HT-PEMFC at various experimental conditions is presented, particularly at several CO concentrations (up to 1.0%). Polarization curves measured at various anode (1.0-2.5) and cathode (1.6-4.0) stoichiometries; stack operating temperatures (120-160 C) and gas pressures (up to 0.5 bar_g) are reported and analysed. The minimum gas stoichiometries of 1.25 and 2.0 were determined for the anode and cathode, respectively. The highest stack power density of 225 mW cm^-2 was measured at 160 C and 0.4 A cm^-2. Operation at CO concentrations up to 1% was achieved, although a loss of performance of about 4% was observed for low CO concentrations. The operating temperature enhanced fuel cell performance and tolerance to CO, even when supplied with higher CO concentration in the anode feed gas.