Mechanical reliability and life prediction of coated metallic interconnects within solid oxide fuel cells

RENEWABLE ENERGY

卷:113

Article

Xu, Zhijie¹  Xu, Wei²  Stephens, Elizabeth³  Koeppel, Brian³ 

[1] Pacific Northwest Natl Lab, Phys & Computat Sci Directorate, Computat Math Grp, Richland, WA 99352 USA

[2] Pacific Northwest Natl Lab, Phys & Computat Sci Directorate, Computat Engn Grp, Richland, WA 99352 USA

[3] Pacific Northwest Natl Lab, Energy & Environm Directorate, Richland, WA 99352 USA

关键词: Solid oxide fuel cell (SOFC);    Ferritic stainless steel interconnect;    Coating;    Fracture mechanics;   

DOI  :  10.1016/j.renene.2017.06.103

来源: Elsevier

【 摘 要 】

Metallic cell interconnects (IC) made of ferritic stainless steels, i.e., iron-based alloys, have been increasingly favored in the recent development of planar solid oxide fuel cells (SOFCs) because of their advantages in excellent imperviousness, low electrical resistance, ease in fabrication, and cost effectiveness. Typical SOFC operating conditions inevitably lead to the formation of oxide scales on the surface of ferritic stainless steel, which could cause delamination, buckling, and spallation resulting from the mismatch of the coefficient of thermal expansion and eventually reduce the lifetime of the interconnect components. Various protective coating techniques have been applied to alleviate these drawbacks. In the present work, a fracture-mechanics-based quantitative modeling framework has been established to predict the mechanical reliability and lifetime of the spinel-coated, surface-modified specimens under an isothermal cooling cycle. Analytical solutions have been formulated to evaluate the scale/substrate interfacial strength and determine the critical oxide thickness in terms of a variety of design factors, such as coating thickness, material properties, and uncertainties. The findings then are correlated with the experimentally measured oxide scale growth kinetics to quantify the predicted lifetime of the metallic interconnects. (C) 2017 Elsevier Ltd. All rights reserved.

【 授权许可】

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