反応性添加物を用いたSOFC空気極のガラス質不純物への耐性の向上に関する研究

快速氧交换动力学是固体氧化物燃料电池（SOFC）电极的一个关键指标，但即使是少量杂质的存在也会极大地阻碍氧交换动力学。例如，硅在陶瓷加工中很常见。研究发现，在SOFCs混合离子电子导电电极Pr0.1Ce0.9O2-d （PCO）致密薄膜上，氧交换动力学发生了快速降解。提出了一种新的光传输弛豫（OTR）技术来帮助测量裸膜表面的动力学。该技术的一个关键优点是它不需要传统测量中典型的电流收集器。通过TEM和XPS鉴定，硅是电极表面的重要杂质，在电极表面形成一层阻挡层。发现氧化镧膜的沉积可使所测样品的氧交换动力学完全恢复。通过O1s XPS峰的位移和对可能与Si（如La， Sm氧化物）和不与Si（如Nb， Ti， Zn氧化物）发生反应的薄膜的系统OTR研究，发现La和Si氧化物相互作用。这些结果表明，La可能“清洁”SOFC电极的表面，从而显着改善氧运输动力学。La-PCO固溶体上OTR的初步测量表明，长期电极动力学稳定性得到改善，证明了该方法在实现硅杂质耐受方面的商业潜力。

Fast oxygen exchange kinetics, a key figure of merit in solid oxide fuel cell (SOFC) electrodes, is often dramatically hindered by the presence of even small concentrations of impurities. Si, for example, is common in ceramics processing. It was found that rapid degradation of oxygen exchange kinetics occurred on dense thin films of Pr0.1Ce0.9O2-d (PCO), a mixed ionic electronic conducting electrode for SOFCs. A new optical transmission relaxation (OTR) technique was developed to aid in measuring kinetics on the bare film surfaces. A key advantage of this technique is that it does not require current collectors typical of conventional measurements. Si was identified by TEM and XPS as a significant surface impurity, which forms a blocking layer on the electrode surface. Deposition of a La oxide film was found to result in full recovery of oxygen exchange kinetics on the measured sample. La and Si oxides were found to interact with each other as identified by a shift in the O1s XPS peak and a systematic OTR study of films that likely react with Si (e.g. La, Sm oxides) and those that do not (e.g. Nb, Ti, Zn oxides). These results indicate that La may "clean" the surface of the SOFC electrode, thereby dramatically improving oxygen transport kinetics. Preliminary measurements of OTR on a La-PCO solid solution indicates improved long-term electrode kinetics stability, demonstrating the commercial potential of this method to achieve Si impurity tolerance.