Quantitative three-dimensional microstructure of a solid oxide fuel cell cathode
Quantitative three-dimensional microstructure of a solid oxide fuel cell cathode
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DOI：
10.1016/j.elecom.2009.03.010
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发表时间：
2009-05
影响因子：
5.4
通讯作者：
James R. Wilson;A. Duong;Marcio Gameiro;Hsun-Yi Chen;K. Thornton;D. Mumm;S. Barnett
中科院分区：
文献类型：
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作者：
James R. Wilson;A. Duong;Marcio Gameiro;Hsun-Yi Chen;K. Thornton;D. Mumm;S. Barnett
固体氧化物燃料电池(SOFC)正在全球范围内被积极开发，用于从天然气、氢、煤和汽油等燃料中清洁高效地发电。目前技术水平的SOFC阴极通常是由电子导电的La1SrxMnO3(LSM)和离子导电的Y2O3稳定的−(YSZ)组成的多孔复合材料，有助于临界氧还原反应。在这里，我们描述了LSM-YSZ阴极的关键结构参数的三维表征和量化，使用基于聚焦离子束扫描电子显微镜的成像和体积重建。确定了LSM-YSZ-孔三相边界(TPBS)。大约1/3的TPB在分离的LSM颗粒上是电化学不活跃的，其活性TPB密度为4.9μm−2。阴极电化学模拟，包括测量的YSZ曲折度3.4，在80 0°C时得到有效的TPB电阻为≈2.5×10 5Ωcm。
Solid oxide fuel cells (SOFCs) are being actively developed world wide for clean and efficient electrical generation from fuels such as natural gas, hydrogen, coal, and gasoline. The cathode in state of the art SOFCs is typically a porous composite of electronically-conducting La1−xSrxMnO3(LSM) and ionically-conducting Y2O3-stabilized ZrO2(YSZ) that facilitates the critical oxygen reduction reaction. Here we describe the three-dimensional characterization and quantification of key structural parameters from an LSM-YSZ cathode, using imaging and volume reconstruction based on focused ion beam – scanning electron microscopy. LSM-YSZ-pore three-phase boundaries (TPBs) were identified. Approximately 1/3 of the TPBs were found to be electrochemically inactive, as they were on isolated LSM particles, yielding an active TPB density of 4.9μm−2. Cathode electrochemical modeling, which included a measured YSZ tortuosity of 3.4, yielded an effective TPB resistance of ≈2.5×105Ωcm at 800°C.