Nonlinear Harmonic Techniques for Studies of Solid Oxide Fuel Cell Electrodes

用于研究固体氧化物燃料电池电极的非线性谐波技术

• 批准号: 0829171
• 负责人: Stuart Adler
• 金额: $ 30万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0829171&HistoricalAwards=false
• 关键词: Nonlinear; Harmonic; Techniques; Studies; Solid

CBET-0829171AdlerAdvances in ceramic manufacturing have revitalized interest in the solid oxide fuel cell (SOFC) as an efficient means to recover electricity from fossil and renewable hydrocarbons, including biomass. Developers have successfully lowered operating temperatures of SOFCs below 600°C, leading to improved reliability and reduced capital cost. One factor leading to these successes has been the use of alternate electrode materials based on mixed-conducting ceramics (materials which carry both oxygen ions and electrons), often called mixed conductors. Although promising, the reason mixed-conductors improve performance remains unclear, and they also suffer from poorly-understood degradation problems. In order to develop a better understanding of how mixed-conductors work as electrodes, Adler and his coworkers at the University of Washington have been developing a new electrochemical measurement technique called "nonlinear electrochemical impedance spectroscopy" (NLEIS). This technique relies on small (almost immeasurable) harmonic signals generated when an oscillating current is passed through the electrode. A relevant analogy is music. The reason you can tell the difference between different instruments playing the same note is that each instrument also generates harmonic and anharmonic tones in conjunction with the primary tone being played. These small extra signals are detected by your ear, and act like a fingerprint for the physical process generating them (vibrating string of a guitar, resonating wooden cavity of a violin, etc). In the same way NLEIS helps the Adler group figure of what physical of chemical process is limiting or degrading electrode performance. In this renewal, Adler's group will use NLEIS to study an array of materials (SOFC cathodes and anodes) having well-defined microstructure made by pulsed-laser deposition and nanofabrication. They will also further develop the technique, including methods for improved acquisition and interpretation of NLEIS data.Intellectual Merit of the Proposed Activity - The proposed work forms part of a broader effort to better understand high-temperature solid-state electrode reactions, of critical importance to several technologies including solid oxide fuel cells, oxide sensors, and oxygen separation devices. This project involves original and transformative concepts in both experimental techniques and theory/modeling, and will complement more applied projects involving fuel cell electrode development (DOE/SECA), and understanding the electrocatalytic role of 3-D microstructure using FIB-SEM (NSF collaborative research grant with Northwestern University). The principal investigator has 19 years of academic and industrial experience in this field, while the proposing institution is a world leader in electrochemical engineering and electrocatalysis. The proposed work would also advance a burgeoning international collaboration between the University of Washington and Tohoku University, one of the world's leading institutes for high-temperature electrochemical materials. Broader Impacts of the Proposed Work - In addition to gaining knowledge of direct interest to SOFC's, this work will develop transformative techniques of general interest in other areas of electrochemical engineering, including membrane fuel cells (of all types), solid-state and thin-film batteries, electrochemical materials processing, electrochemical sensors, coatings and thin films, and other solid-state interfacial devices. This work will support the education of individual scientists and engineers (including at least one women), and involve opportunities for students to participate in both national and international collaborative research. Results and knowledge will be disseminated widely through the literature, while strong ties of the PI to industry and more applied programs will aid direct impact on commercial development. This research program will also directly enhance the PI's educational program, which includes internet-based UW courses on fuel cells, and an Electrochemical Society short course.

CBET-0829171 Adler陶瓷制造的进步重新激发了人们对固体氧化物燃料电池(SOFC)的兴趣，SOFC是从化石和可再生碳氢化合物(包括生物质)中回收电力的有效手段。开发商已成功地将SOFC的工作温度降低到600°C以下，从而提高了可靠性并降低了资本成本。导致这些成功的一个因素是使用了基于混合导电陶瓷(同时携带氧离子和电子的材料)的替代电极材料，通常被称为混合导体。尽管混合导体很有希望，但改善性能的原因尚不清楚，而且它们还存在人们知之甚少的退化问题。为了更好地了解混合导体是如何作为电极工作的，华盛顿大学的Adler和他的同事们一直在开发一种新的电化学测量技术，称为非线性电化学阻抗谱(NLEIS)。这项技术依赖于振荡电流通过电极时产生的微小(几乎无法测量)的谐波信号。一个相关的类比是音乐。你之所以能分辨不同乐器演奏同一音符的不同之处，是因为每种乐器在演奏主音的同时，也会产生谐音和非谐音。这些微小的额外信号被你的耳朵探测到，就像产生它们的物理过程的指纹一样(吉他的振动弦，小提琴的共鸣木腔等)。以同样的方式，NLEIS帮助Adler小组计算出是什么物理的化学过程限制或降低了电极的性能。在这次更新中，Adler的团队将使用NLEIS来研究一系列材料(SOFC阴极和阳极)，这些材料具有明确的微结构，由脉冲激光沉积和纳米加工制成。他们还将进一步开发这项技术，包括改进NLEIS数据获取和解释的方法。拟议活动的智力价值-拟议的工作是更广泛努力的一部分，以更好地了解高温固态电极反应，这对包括固体氧化物燃料电池、氧化物传感器和氧分离设备在内的几项技术至关重要。该项目在实验技术和理论/模型方面都涉及到原创性和变革性的概念，并将补充更多的应用项目，包括燃料电池电极的开发(DOE/SEA)，以及使用FIB-SEM(NSF与西北大学合作研究基金)了解三维微结构的电催化作用。首席研究员在这一领域拥有19年的学术和工业经验，而提议的机构是电化学工程和电催化领域的世界领先者。这项拟议的工作还将推动华盛顿大学和东北大学之间蓬勃发展的国际合作。东北大学是世界领先的高温电化学材料研究所之一。拟议工作的更广泛影响-除了获得与SOFC直接相关的知识外，这项工作还将开发在其他电化学工程领域普遍感兴趣的变革性技术，包括膜燃料电池(所有类型)、固态和薄膜电池、电化学材料处理、电化学传感器、涂层和薄膜以及其他固态接口设备。这项工作将支持科学家和工程师个人(包括至少一名女性)的教育，并为学生提供参与国家和国际合作研究的机会。结果和知识将通过文献广泛传播，而PI与行业和更多应用程序的紧密联系将有助于直接影响商业发展。这项研究计划还将直接加强PI的教育计划，其中包括基于互联网的燃料电池UW课程和电化学学会短期课程。