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Title: Theoretical Analysis of Critical Conditions for Crack Formation and Propagation, and Optimal Operation of SOECs

A theoretical analysis on crack formation and propagation was performed based on the coupling between the electrochemical process, classical elasticity, and fracture mechanics. The chemical potential of oxygen, thus oxygen partial pressure, at the oxygen electrode-electrolyte interface (μO2OE∣El) was investigated as a function of transport properties, electrolyte thickness and operating conditions (e.g., steam concentration, constant current, and constant voltage). Our analysis shows that: a lower ionic area specific resistance (ASR),riOE,and a higher electronic ASR (reOE) of the oxygen electrode/electrolyte interface are in favor of suppressing crack formation. TheμO2OEEl,thus local pO2, are sensitive towards the operating parameters under galvanostatic or potentiostatic electrolysis. Constant current density electrolysis provides better robustness, especially at a high current density with a high steam content. While constant voltage electrolysis leads to greater variations ofμO2OEEl.Constant current electrolysis, however, is not suitable for an unstable oxygen electrode becauseμO2OEElcan reach a very high value with a gradually increasedriOE.A crack may only occur under certain conditions whenpO2TPB>pcr.

 
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Award ID(s):
2119688
NSF-PAR ID:
10366633
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
The Electrochemical Society
Date Published:
Journal Name:
Journal of The Electrochemical Society
Volume:
169
Issue:
4
ISSN:
0013-4651
Page Range / eLocation ID:
Article No. 044529
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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