混合导体的二维电化学模型：氧化铈的研究
Two-dimensional electrochemical model for mixed conductors: a study of ceria
摘要：
建立了对称气体环境中图案化金属集流体$|$混合氧离子和电子导体（MIEC）$|$图案化金属集流体电化学电池的二维小偏压模型。具体来说，我们计算的电化学电位分布的氧空位和电子在体和表面附近的$\text{Pt} | \text{Sm}_{0.15}\text{Ce}_{0.85}\text{O}_{1.925} | \text{Pt}$对称电池在$\text{H}_2-\text{H}_2\text{O}-\text{Ar}$（还原）气氛从500到$650^o C$。使用一个二维有限元模型，我们表明，两种类型的电子电流存在于电池内：一个面内漂移扩散电流之间的气体$|$氧化铈化学反应位点和金属集流体流动，和一个跨平面电流之间的两个金属电极上的电池的相对侧流动。通过拟合的表面反应常数$\tilde k_f^0$的实验电极电阻值，同时固定的材料性能，如体离子和电子平衡缺陷浓度和迁移率，我们能够分离成表面反应组件和面内电子漂移扩散组件的电极极化。我们表明，对于混合导体具有低的电子电导率（氧分压的函数）或高的表面反应速率常数，在平面内的电子漂移扩散电阻可以成为在电极反应的速率限制。
英文摘要：
A two-dimensional small bias model has been developed for a patterned metal current collector $|$ mixed oxygen ion and electronic conductor (MIEC) $|$ patterned metal current collector electrochemical cell in a symmetric gas environment. Specifically, we compute the electrochemical potential distributions of oxygen vacancies and electrons in the bulk and near the surface for $\text{Pt} | \text{Sm}_{0.15}\text{Ce}_{0.85}\text{O}_{1.925} | \text{Pt}$ symmetric cell in a $\text{H}_2-\text{H}_2\text{O}-\text{Ar}$ (reducing) atmosphere from 500 to $650^o C$. Using a two-dimensional finite-element model, we show that two types of electronic current exist within the cell: an in-plane drift-diffusion current that flows between the gas $|$ ceria chemical reaction site and the metal current collector, and a cross-plane current that flows between the two metal electrodes on the opposite side of the cell. By fitting the surface reaction constant $\tilde k_f^0$ to experimental electrode resistance values while fixing material properties such as bulk ionic and electronic equilibrium defect concentrations and mobilities, we are able to separate the electrode polarization into the surface reaction component and the in-plane electron drift-diffusion component. We show that for mixed conductors with a low electronic conductivity (a function of oxygen partial pressure) or a high surface reaction rate constant, the in-plane electron drift-diffusion resistance can become rate-limiting in the electrode reaction.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
