Bulk and Surface Properties of New Materials for Solid Oxide Fuel Cell Electrodes

固体氧化物燃料电池电极新材料的体积和表面性能

• 批准号: 226166566
• 负责人: Professor Dr. Bernd Meyer
• 金额: --
• 依托单位: Computer-Chemie-Centrum (CCC)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/226166566?language=en
• 关键词: Bulk; Surface; Properties; New; Materials

Further improvement of the efficiency and thermal stability of solid oxide fuel cells (SOFCs) requires alternative electrode materials that allow to lower the operating temperature of fuel cells to 600-800 C. Two innovative new classes of cathode and anode materials with promising electronic/ionic conductivity and catalytic activity at lower temperatures are layered cobalt oxide compounds with YBaCo4O7 structure and Sr2MgMoO6-based double-perovskites, respectively. The electronic/ionic and catalytic properties of both compounds can be tuned by substitution with a wide variety of elements on the different sublattices, which also modifies their thermal phase stability. Another very promising strategy for improving solid oxide fuel cell performance is to use liquid Sn anodes high-temperature SOFCs. They are distinguished by high robustness and low sensitivity to fuel contaminations.The overall aim of this project is to obtain a better understanding of the bulk and surface properties of these new classes of SOFC anode and cathode materials on an atomistic level by means of first-principles calculations based on density functional theory. By studying the interaction with oxygen and small fuel molecules (H2, CH4, CO) we will simulate the processes that occur during SOFCs working conditions on the cathode and anode sides, respectively. We will focus on the thermodynamic stability of bulk phases and surface structures and search for the most stable surface configurations and compositions in different environments at given temperature and partial pressures. The influence of substituents on the electronic properties, on oxygen vacancy formation and on phase stability will be investigated. Insights into the kinetics of oxygen migration inside the bulk, on the surfaces and at the electrode/electrolyte interfaces shall be obtained by calculation of activation barriers. The mechanisms of these processes that govern the oxygen uptake at the cathode, the fuel oxidation at the anode and the phase stability at the electrode/electrolyte interfaces are still basically unknown. A better understanding shall contribute to a knowledge-based improvement of the chemical and thermal properties of these new classes of materials for future SOFC applications.

固体氧化物燃料电池（SOFC）的效率和热稳定性的进一步改进需要允许将燃料电池的操作温度降低到600-800 ℃的替代电极材料。两个创新的新类别的阴极和阳极材料具有有前途的电子/离子导电性和催化活性在较低的温度下的层状钴氧化物化合物与YBaCo 4 O 7结构和Sr 2 MgMoO 6基双钙钛矿，分别。这两种化合物的电子/离子和催化性质可以通过在不同的亚晶格上用各种各样的元素取代来调节，这也改变了它们的热相稳定性。另一个非常有前途的改善固体氧化物燃料电池性能的策略是使用液体锡阳极高温SOFC。本项目的总体目标是通过基于密度泛函理论的第一性原理计算，在原子水平上更好地了解这些新型SOFC阳极和阴极材料的体积和表面性质。通过研究与氧气和小燃料分子（H2，CH 4，CO）的相互作用，我们将分别模拟SOFC阴极和阳极侧工作条件下发生的过程。我们将专注于体相和表面结构的热力学稳定性，并在给定的温度和分压下，在不同的环境中寻找最稳定的表面配置和组合物。取代基的电子性质的影响，对氧空位的形成和相稳定性将进行调查。应通过计算活化屏障，深入了解主体内部、表面和电极/电解质界面处的氧迁移动力学。这些过程的机制，管理在阴极的氧吸收，在阳极的燃料氧化和在电极/电解质界面的相稳定性仍然基本上是未知的。更好的理解将有助于以知识为基础的化学和热性能的改进，这些新类别的材料，为未来的固体氧化物燃料电池应用。