Effect of humidification on the performance of intermediate-temperature proton conducting ceramic fuel cells with ceramic composite cathodes

摘要

The effect of variations in flow rate and the humidity content of the cathode and anode gases on the performance of BaCe_(0.85)Y_(0.15)O_(3-δ) electrolyte-based proton conducting ceramic fuel cell with ceramic composite cathodes are studied. Increased flow rate of gases has positive effect but the presence of humidity in the cathode/anode gases has negative effect on the performance. The effect of humidity is more pronounced when it is present in the cathode gas than when it is present in the anode gas. Also, the effect of humidity is dependent on the nature of the cathode material; in the case of La_(0.8)Sr_(0.2)MnO_3-Gd_(0.1)Ce_(0.9)O_(1.95) cathode some of the reaction sites are occupied by H_2O vapor and which leads to increase in the charge transfer resistance. Replacing Lao.8Sro.2MnO_3-Gd_(0.1)Ce_(0.9)O_(1.95) with La_(0.8)Sr_(0.2)MnO_3-BaCe_(0.85)Y_(0.15)O_(3-δ) cathode leads to an increase in the effective area of three phase boundary, which mitigates the adverse effects of humidity to a certain extent.