Characterisation of Ni-YSZ-Cermets with respect to redox stabilityx

被引：37
作者：
Ettler, M. [1 ]
Blass, G. [1 ]
Menzler, N. H. [1 ]
机构：
[1] Forschungszentrum Julich, Inst Energy Res IEF 1, DE-52425 Julich, Germany
来源：
FUEL CELLS | 2007年 / 7卷 / 05期
关键词：
characeterisation; experimental results; Ni-YSZ; cermet anode; redox stability; solide oxide fuel cell;
D O I：
10.1002/fuce.200700007
中图分类号：
O646 [电化学、电解、磁化学];
学科分类号：
081704 ;
摘要：
In anode-supported solid oxide fuel cells (SOFCs), air break-in on the anode side can result in reoxidation of metallic nickel. The volume expansion caused by Ni oxidation generates stresses within the substrate, the anode and the electrolyte. Those stresses exceed the stability of the components, potentially promoting crack growth. Therefore, either the SOFC degrades continuously after each redox-cycle or the membrane electrode assembly (MEA) fails completely if the electrolyte cracks. The influence of several reoxidation parameters on the mechanical integrity of Ni-YSZ-anodes after reoxidation was investigated using different types of samples. All samples were SFEs (substrate-functional layer-electrolytes), consisting of Ni-YSZ-substrate, Ni-YSZ-anode and YSZ-electrolyte. Investigations were carried out on freestanding SFEs and SFEs attached to steel plates (Crofer22APU, Thyssen Krupp V. D. M., Material Data Sheet No. 4046, Edition of December 2006) with a glass sealing. The results show a big influence of the degree of oxidation, homogeneity of oxidation, the operating temperature and the incident flow on the behaviour and the mechanical integrity of the reoxidised SFEs. The time of oxidation and the gas flow rate were influencing parameters, whereas the influence of the porosity was insignificant. The behaviour of the SFEs upon reoxidation also changes dramatically when comparing freestanding samples with attached samples.
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页码：349 / 355
页数：7
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