Collaborative Research: Three-Dimensional Microstructural and Chemical Mapping of Solid Oxide Fuel Cell Electrodes: Processing, Structure, Stability, and Electrochemistry

提案名称：合作研究：固体氧化物燃料电池电极的三维微观结构和化学测绘：加工、结构、稳定性和电化学。机构：西北大学。摘要：日期：06/11/09该奖项由2009年美国复苏和再投资法案（公法111-5）资助。非技术描述：固体氧化物燃料电池（sofc）为将燃料转化为电能提供了一个重要的新选择，提高了效率，减少了污染，减少了温室气体排放。从这项技术中获得商业和环境效益的竞赛在很大程度上取决于实际问题，包括成本和设备可靠性。该项目旨在通过获取和分析燃料电池的三维图像，更好地了解SOFC性能和可靠性与制造方法和组成材料特性之间的关系。这些图像可以用来确定哪些结构可以提高性能，从而降低成本，找到产生所需结构/化学的制造条件，并检查导致燃料电池随着时间的推移而退化的因素。改进后的结构和化学信息将分发给燃料电池研究和开发社区，在那里它将有助于建立关键的联系，例如工业开发商之间的联系。谁需要可靠的性能/寿命预测？建模师呢？他们需要良好的结构/化学信息来做出这样的预测。大量的研究生和本科生，在许多情况下来自代表性不足的群体，将通过这个项目接受培训。还有一些其他的教育影响，包括高中科学教师参加暑期研究。技术细节：关于电极结构和界面化学的有限定量信息对燃料电池性能和稳定性的基本理解构成了主要障碍。这个重点研究小组正在研究关键SOFC材料的加工、结构和电化学性能之间的关系，利用一套基于聚焦离子束的工具？扫描电子显微镜（FIB-SEM）来确定SOFC电极的三维（3D）微观结构。该项目包括制造最先进的sofc，使用新型阻抗谱方法进行详细的电化学表征，使用FIB-SEM进行结构测量，将数据分割成3D相图，微观结构的可视化，宏观均匀结构参数的提取，以及直接基于3D数据集的微观结构粗化和电化学极化模拟。通过分析扫描透射电子显微镜（TEM）分析和同步加速器x射线方法获得了有关相互扩散，阳离子和/或杂质在界面和第二相的积累的其他信息。这种3D微观结构信息的可用性将有助于将我们对燃料电池电极如何工作的理解转变为更定量的科学。该项目的广泛影响包括全国研究人员/开发人员可用的3D结构数据库的持续增长，以及与更广泛的3D微观结构社区相关的分析工具的开发。参与该项目的学生和教师将接受有关燃料电池制造、电化学测试、显微镜和材料建模的最新工具的培训。

Proposal Title: Collaborative Research: Three-Dimensional Microstructural andChemical Mapping of Solid Oxide Fuel Cell Electrodes: Processing,Structure, Stability, and ElectrochemistryInstitution: Northwestern UniversityAbstract Date: 06/11/09This award is funded under the American Recovery and Reinvestment Act of 2009(Public Law 111-5).NON-TECHNICAL DESCRIPTION:Solid oxide fuel cells (SOFCs) offer an important new option for converting fuels to electricity with increased efficiency, reduced pollution, and reduced greenhouse gas emissions. The race to reap the commercial and environmental benefits of this technology is largely being decided by practical issues, including cost and device reliability. The proposed project seeks to better understand how SOFC performance and reliability are linked to manufacturing methods and constituent materials properties, by the acquisition and analysis of three-dimensional images of the fuel cells. Such images can be used to determine what structures yield improved performance and hence reduced cost, find manufacturing conditions that yield the desired structure/chemistry, and examine the factors causing fuel cells to degrade over time.The improved structural and chemical information will be disseminated to the fuel cell research and development community where it will help enable critical connections, for example between industrial developers ? who need reliable performance/lifetime predictions ? and modelers ? who require good structural/chemical information to make such predictions. A substantial number of graduate and undergraduate students, in many cases from underrepresented groups, will receive training through this project. There are a number of other educational impacts, including high-school science teachers participating in summer research.TECHNICAL DETAILS:The limited quantitative information available on electrode structure and interfacial chemistry poses a major barrier to fundamental understanding of fuel cell performance and stability. This Focused Research Group is examining the relationships between the processing, structure, and electrochemical properties of key SOFC materials, utilizing a set of tools based on focused ion beam ? scanning electron microscopy (FIB-SEM) to determine the microstructure of SOFC electrodes in three-dimensions (3D). The projectincludes fabrication of state-of-the-art SOFCs, detailed electrochemical characterization using novel impedance spectroscopy methods, structural measurement using FIB-SEM, segmentation of the data into 3D phase maps, visualization of the microstructures, extraction of macrohomogeneous structural parameters, and simulations of microstructural coarsening and electrochemical polarization based directly on 3D data sets. Additional information regarding interdiffusion, accumulation of cation speciesand/or impurities at interfaces, and second phases is obtained with analytical scanning transmission electron microscope (TEM) analysis and synchrotron X-ray methods. Availability of this 3D microstructure information will be instrumental for transforming our understanding of how fuel cell electrodes work to a more quantitative science. Broad impacts of the project include the continued growth of a 3D structural data library available to researchers/developers nationwide, and development of analysis toolsrelevant to the broader 3D microstructure community. Students and teachers involved in the project receive training on state of the art tools for fuel-cell fabrication, electrochemical testing, microscopy, and materials modeling.