In order to investigate the relevant factors affecting the transport properties of solid oxide fuel cell cathodes upon coating with Ce_0.9Gd_0.1O_1.95 (GDC), the surface oxygen exchange coefficient, k*, and oxide ion diffusivity, D*, of La_0.6Sr_0.4CoO_3-δ (LSC) and La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ (LSCF) were measured by a combination of isotope exchange technique and secondary ion mass spectrometry (SIMS). The k* of LSCF/GDC enhanced compared to a bare LSCF for all measured temperatures. In contrast, the k* of LSC/GDC only showed an enhancement compared to the bare LSC at relatively low temperatures (below 873 K) but not at higher temperatures. From these results, GDC has a less significant effect on the k* of LSC compared to LSCF. This suggests that the enhancement of k* is possibly induced only when the oxygen vacancy concentration, δ, of the cathode is lower than that of GDC, although another factor may affect the enhancement. The enhancement of k* is attributed to the formation of triple-phase boundary where a spill-over mechanism controlled the oxygen reduction reaction. The change of rate-determining step of LSCF due to the GDC coating suggests that the enhancement of the k* is not only with respect to the incorporation process, but it is possibly enhancing the reaction steps that involve δ as well.

为了研究影响涂覆有Ce _0.9 Gd _0.1 O _1.95（GDC）的固体氧化物燃料电池阴极运输性能的相关因素，La _0.6的表面氧交换系数k *和氧化物离子扩散率D * Sr _0.4 CoO _{3- δ}（LSC）和La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O _{3- δ}（LSCF）是通过同位素交换技术和二次离子质谱（SIMS）组合测量的。该ķ与所有测量温度下的裸LSCF相比，*的LSCF / GDC有所增强。相反，在相对较低的温度（低于873 K）下，LSC / GDC的k *仅比裸LSC有所提高，而在较高的温度下则没有。从这些结果来看，与LSCF相比，GDC对LSC的k *的影响较小。这表明，只有当阴极的氧空位浓度δ低于GDC的空位浓度δ时，才可能诱导k *的增强，尽管其他因素可能会影响该增强。k的增强*归因于三相边界的形成，其中溢出机制控制了氧还原反应。LSCF速率决定步骤的变化归因于GDC涂层，这表明k *的提高不仅与掺入过程有关，而且还可能增强涉及δ的反应步骤。