燃料および空気欠乏下での固体高分子形燃料電池セル面内の電位分布の解析

抄録

The changes in the anode and cathode potentials in the horizontal plane of a polymer electrolyte fuel cell (PEFC) under starving conditions for either air or fuel were studied using a single cell furnished with four reference electrodes which were located around the anode and the cathode. The distance between a reference electrode and the anode (or the cathode) was only 2 mm. When air starvation occurred, the cathode potentials approached 0 V against RHE, but the distribution of potentials in the horizontal plane of the cell was little changed. When fuel starvation occurred, the difference between the cathode potential in the fuel outlet area and that in the fuel inlet area increased. Immediately after the termination of fuel starvation, the cathode potential in the fuel outlet area shifted quickly and remarkably toward the positive, and it exceeded 1 V against RHE in a few seconds. When fuel supplied to the anode where air had been occupied, the cathode potential in the fuel outlet area reached to 1.5 V vs. RHE, and high possibility of corrosion was suggested at that area. These results are similar to the case of phosphoric acid fuel cell (PAFC).