Dynamics of anode-cathode interaction in a polymer electrolyte fuel cell revealed by simultaneous current and potential distribution measurements under local reactant-starvation conditions

摘要

Low stoichiometry operation of fuel cells induces nonuniformities in the current generation and electrode potentials across the active electrode area. In this study, current and potential distributions are measured simultaneously in a fuel cell operating under reactant (fuel/air)-starvation conditions. During the galvanostatic operation under local reactant starvation, the localized increase of current density is observed closer to the inlet. Here under air starvation, cathode potentials dropped uniformly across the electrode area. However, during fuel starvation, a nonuniform cathode potential profile is observed. During the potentiostatic mode of operation under air-starvation condition, cathode potentials remained uniform and constant across the electrode area. However, under fuel starvation, the cathode potential profile is influenced by the anode potential profile. Electrode-electrode interaction especially during fuel starvation is captured by simultaneous measurements of current and potential distribution.