@article {1166,
	title = {The oxygen partial pressure in solid oxide electrolysis cells with multilayer electrolytes},
	journal = {Acta Materialia},
	volume = {213},
	year = {2021},
	pages = {116928},
	abstract = {A number of degradation mechanisms have been observed during the long-term operation of solid oxide electrolysis cells (SOEC). Using an electrolyte charge carrier transport model and a diffuse interface treatment for a multilayer electrolytes, we quantify the oxygen potentials across the electrolyte and thereby provide insights into these degradation mechanisms. Our model describes the transport of charge carriers in the electrolyte when the oxygen partial pressure is extremely low by accounting for the spatial variation of the concentration of oxygen vacancies in the electrolyte which is closely related to the degradation of the SOEC near the interface of hydrogen electrode and electrolyte. Moreover, we identify four quantities that characterize the distribution of oxygen partial pressure in the electrolyte, which are directly related to the degradation mechanisms in the electrolyte as well, and give analytical estimates for them. These analytical expressions provide guidance on the parameters that need to be controlled to suppress the degradation observed in the electrolyte.},
	keywords = {Diffuse interface model, Multilayer electrolyte, Oxygen partial pressure, solid oxide electrolysis cell},
	issn = {1359-6454},
	doi = {https://doi.org/10.1016/j.actamat.2021.116928},
	url = {https://www.sciencedirect.com/science/article/pii/S1359645421003086},
	author = {Qian Zhang and Qin-Yuan Liu and Beom-Kyeong Park and Scott Barnett and Peter Voorhees}
}
@article {1184,
	title = {Effect of direct-current operation on the electrochemical performance and structural evolution of Ni-YSZ electrodes},
	journal = {Journal of Physics: Energy},
	volume = {2},
	year = {2019},
	month = {12/2019},
	pages = {014006},
	abstract = {The effect of electrolysis operations on Ni-YSZ fuel electrode stability was studied at different current densities and fuel mixtures during 1000 h life tests. For a typical electrolysis mixture of 50\% H2/50\% H2O and 0.6 A cm-2 current density, cell ohmic resistance values were reasonably stable and no structural changes occurred. However, for more reducing conditions (97\% H2/3\% H2O), increasing the current density above 0.4 A cm-2 increased the ohmic resistance accompanied by significant electrolyte degradation including fracture and void formation at grain boundaries. Numerical analysis was carried out to determine the effective oxygen partial pressure across the electrolyte. The results show that the oxygen partial pressure values at high current density and low steam content may be low enough to reduce zirconia to form a Ni-Zr alloy product, initiating the observed electrolyte structural degradation.},
	keywords = {durability, HTE, SOEC, Yttria-stabilized zirconia},
	doi = {10.1088/2515-7655/ab59a6},
	url = {https://doi.org/10.1088/2515-7655/ab59a6},
	author = {Qinyuan Liu and Qian Zhang and Peter W Voorhees and Scott A Barnett}
}
