分割電極による平板型固体酸化物形燃料電池の直接電流分布測定

抄録

In the planar solid oxide fuel cell (SOFC), the fuel/oxidant distributions cause current and temperature distributions over the electrodes under the separator ribs and flow channels. Optimized design of the separator is hence required to improve the output power and chemical/thermo-mechanical durabilities of practical stacks. In contrast to the numerical analyses, very few experimental investigations clarifying in-situ current distributions have been reported to reveal the influence of the separator structure. We have therefore addressed in-situ measurements of in-plane spatial current variations of an electrolyte-supported planar SOFC using segmented cathodes under the rib and the flow channels. Thereby, we investigate the effect of the rib width on the spatial current distribution. We also model the current and hydrogen partial pressure distributions by finite element modeling so that the model agrees with the in-situ current distributions derived by the segmented cathodes with setting the exchange current densities, electrode porosities, electrolyte ion conductivities, and electrode ion/electron conductivities. This modeling is useful to design separators to improve the performance and durability of practical stacks.