Lu, X;
Heenan, TMM;
Bailey, JJ;
Li, T;
Li, K;
Brett, DJL;
Shearing, PR;
(2017)
Correlation between triple phase boundary and the microstructure of Solid Oxide Fuel Cell anodes: The role of composition, porosity and Ni densification.
Journal of Power Sources
, 365
pp. 210-219.
10.1016/j.jpowsour.2017.08.095.
Preview |
Text
1-s2.0-S037877531731128X-main.pdf - Published Version Download (4MB) | Preview |
Abstract
© 2017 This study aims to correlate the active triple phase boundaries (TPBs) to the variation of as-prepared anode microstructures and Ni densifications based on the reconstructed 3D volume of an SOFC anode, providing a point of comparison with theoretical studies that reveal the relationship of TPBs and the material microstructure using randomly packed spheres models. The TPB degradation mechanisms are explained using a particle network model. The results indicate that in low porosity regime, the TPBs sharply increase with the porosity until the percolation threshold (10%); at intermediate porosity (10%–25%), a balance of surface area between three phases is more critical than that of volume fraction to reach the optimal TPB density; in the high porosity regime ( > 25%), the TPBs start to drop due to the shrinkage and detachment of Ni/YSZ interfaces. The TPB density is inversely proportional to the degree of Ni densification as long as the Ni content is above the percolation threshold (35%) and can be improved by 70% within 7% change of porosity provided that the over-densification is mitigated. This has implications for the design of SOFC microstructures as well for electrode durability, where Ni agglomeration is known to deleteriously impact long-term operation.
Type: | Article |
---|---|
Title: | Correlation between triple phase boundary and the microstructure of Solid Oxide Fuel Cell anodes: The role of composition, porosity and Ni densification |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1016/j.jpowsour.2017.08.095 |
Publisher version: | http://dx.doi.org/10.1016/j.jpowsour.2017.08.095 |
Language: | English |
Additional information: | © 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
Keywords: | X-ray tomography, Ni sintering, Electrode composition, Porosity, TPB degradation, Particle network |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Chemical Engineering UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Electronic and Electrical Eng |
URI: | https://discovery.ucl.ac.uk/id/eprint/10022755 |
Archive Staff Only
View Item |