Development of Nonlinear Harmonic Techniques for Studies of Solid Oxide Fuel Cell Cathodes

用于固体氧化物燃料电池阴极研究的非线性谐波技术的发展

• 批准号: 0412076
• 负责人: Stuart Adler
• 金额: $ 26.14万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-15 至 2008-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0412076&HistoricalAwards=false
• 关键词: Development; Nonlinear; Harmonic; Techniques; Studies

AbstractProposal Title: Development of Nonlinear Harmonic Techniques for Studies of Solid Oxide Fuel Cell CathodesProposal Number: CTS- 0412076Principal Investigator: Stuart AdlerInstitution: University of WashingtonA widespread technique for analyzing fuel cell electrodes and other electrochemical devices is electrochemical impedance spectroscopy (EIS), which seeks to separate and identify physical mechanisms via time scale. While EIS has proven useful, it can be challenging to interpret the impedance of complex systems such as fuel cell electrodes due to wide dispersion and/or overlap among physical processes in the frequency domain, as well as inherent ambiguity in interpreting linearized, low-amplitude response (often described by equivalent circuits) uniquely in terms of physical mechanisms. Upon linearization, many models predict similar or identical impedance behavior, and thus do not provide mechanism-distinguishing characteristics to compare (or fit) to experimental data.This project will develop advanced transient electrochemical techniques that potentially provide much higher resolution than EIS in identifying and quantifying rate-limiting phenomena in solid-oxide fuel cell (SOFC) cathodes. The general approach, which has been called nonlinear EIS (NLEIS) and electrochemical frequency modulation (EFM), involves the measurement of nonlinear 2nd and higher order voltage harmonics resulting from moderate amplitude current perturbations. By the excitation of nonlinear responses and interactions, these techniques potentially offer improved identification of physical steps via nonlinearity and extent of coupling, as well as timescale. These techniques will be developed for SOFC electrodes by studying comprehensively characterized cathodes of well-defined geometry and composition. In order to aid the interpretation of nonlinear harmonic data, mechanistic models will be developed and/or extended for the electrode reaction into the time domain, allowing identification of "fingerprint" harmonic behavior corresponding to specific geometries and reaction mechanisms.

摘要提案题目：研究固体氧化物燃料电池阴极的非线性谐波技术的发展提案编号：CTS- 0412076首席研究员：Stuart adler机构：华盛顿大学分析燃料电池电极和其他电化学装置的广泛技术是电化学阻抗谱（EIS），它试图通过时间尺度分离和识别物理机制。虽然EIS已被证明是有用的，但由于频域物理过程之间的广泛分散和/或重叠，以及在解释线性化、低幅度响应（通常由等效电路描述）时固有的模糊性，解释复杂系统（如燃料电池电极）的阻抗可能具有挑战性。在线性化后，许多模型预测相似或相同的阻抗行为，因此不能提供与实验数据比较（或拟合）的机制区分特征。该项目将开发先进的瞬态电化学技术，在识别和量化固体氧化物燃料电池（SOFC）阴极的速率限制现象方面，该技术可能提供比EIS更高的分辨率。一般的方法，被称为非线性EIS （NLEIS）和电化学调频（EFM），涉及测量由中等幅度电流扰动引起的非线性二阶和高阶电压谐波。通过非线性响应和相互作用的激励，这些技术有可能通过非线性和耦合程度以及时间尺度来改进物理步骤的识别。这些技术将通过研究具有明确几何形状和组成的全面表征的阴极来开发SOFC电极。为了帮助解释非线性谐波数据，将开发和/或将电极反应的机理模型扩展到时域，从而识别与特定几何形状和反应机制相对应的“指纹”谐波行为。