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Studies of Solid Oxide Fuel Cell Electrode Evolution Using 3D Tomography
Author(s) -
YakalKremski K.,
Cronin J. S.,
ChenWiegart Y.C. K.,
Wang J.,
Barnett S. A.
Publication year - 2013
Publication title -
fuel cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.485
H-Index - 69
eISSN - 1615-6854
pISSN - 1615-6846
DOI - 10.1002/fuce.201200177
Subject(s) - materials science , triple phase boundary , yttria stabilized zirconia , solid oxide fuel cell , anode , electrode , oxide , cubic zirconia , chemical engineering , microstructure , composite number , polarization (electrochemistry) , composite material , metallurgy , ceramic , chemistry , engineering
This paper describes 3D tomographic investigations of the structural evolution of Ni‐yttria‐stabilized zirconia (Ni‐YSZ) and (La,Sr)MnO 3 ‐YSZ (LSM‐YSZ) composite solid oxide fuel cell (SOFC) electrodes. Temperatures higher than normally used in SOFC operation are utilized to accelerate electrode evolution. Quantitative 3D FIB‐SEM and X‐ray tomographic imaging contributes to development of mechanistic evolution models needed to accurately predict long‐term durability. Ni‐YSZ anode functional layers annealed in humidified hydrogen at 900–1,100 °C exhibited microstructural coarsening leading to a decrease in three‐phase boundary (TPB) density. There was also a change in the fraction of pores that were isolated, which impacted the density of electrochemically active TPBs. The polarization resistance of optimally fired LSM‐YSZ electrodes increased upon thermal aging at 1,000 °C, whereas that of under‐fired electrodes decreased upon aging. These results are explained in terms of observed 3D microstructural changes.