Microstructural finite element modeling of redox behavior of Ni-YSZ based ceramic SOFC anodes
Küçük Resim Yok
Tarih
2016
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
ELSEVIER SCI LTD
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
One of the main challenges in solid oxide fuel cell (SOFC) is the redox problem of Ni-based anodes. Therefore, the redox tolerance of the anode should be improved to increase the service life of the system. Since the real SOFC anodes have a heterogeneous structure with different grain sizes, a micro-level modeling is necessary. Especially, the re-oxidation step which creates large amount of stress is critical during the redox cycles. Therefore, in this study, the effects of re-oxidation temperatures and exposure times on the oxidation rate and stresses developed are investigated on a synthetically generated porous anode functional layer microstructure. A mathematical model is developed to characterize the re-oxidation process and solved numerically. The results indicate that the re-oxidation strongly depends on the re-oxidation temperature and exposure time. The time required for the full oxidation is found to be 7458.55, 313.14, 200.8 and 33.78 s at 800, 850, 900 and 950 degrees C, respectively for the generated anode microstructure. In addition, the created stresses in the anode structure are well above the critical material limits. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
Açıklama
Anahtar Kelimeler
Synthetic SOFC anode microstructure, Re-oxidation, FEM
Kaynak
CERAMICS INTERNATIONAL
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
42
Sayı
7
