eprintid: 10070734 rev_number: 34 eprint_status: archive userid: 608 dir: disk0/10/07/07/34 datestamp: 2019-04-25 11:20:35 lastmod: 2020-10-05 21:24:25 status_changed: 2019-04-25 11:20:35 type: thesis metadata_visibility: show creators_name: Bailey, Joshua James title: Monitoring the Microstructural Evolution of Solid Oxide Fuel Cell Anodes ispublished: unpub divisions: UCL divisions: A01 divisions: B04 divisions: C05 divisions: F46 note: Copyright © The Author 2019. Original content in this thesis is licensed under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) Licence (https://creativecommons.org/licenses/by/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. abstract: As the global energy landscape evolves in the face of climate change, the uptake of intermittent renewables is gaining ground. Electrochemical devices for energy generation and storage are therefore becoming increasingly prevalent. Solid oxide fuel cells represent an energy conversion device with high efficiency and fuel versatility but continue to suffer from cost and durability issues, hindering commercial viability. Establishing electrode microstructure-property relationships provides insight into both initial and long term performance and thus far, full comprehension of degradation phenomena has remained elusive. Building on 2D stereological approaches, recent advances in tomographic techniques such as focused-ion beam-scanning electron microscopy and X-ray nano computed tomography have allowed for 3D investigations of electrode microstructures. However, the former methodology is inherently destructive and with the latter, reliable contrast for typical SOFC electrode materials has not been easily accessible. In this thesis, an examination of these tomographic modalities is conducted, with focused-ion beam scanning electron microscropy slice and view applied to both virgin and aged Ni-YSZ anodes to virtually reconstruct their microstructures. A laser-preparation technique for the fabrication of geometrically optimised samples for X ray nano-computed tomography is developed, and facilitates access to a larger sampled volume, thus providing more representative characterisation of the entire anode. Prepared samples are exposed to ex-situ annealing in a lab-based furnace wherein 900 °C is identified as the appropriate temperature for monitoring appreciable microstructual evolution within the first 12 hours of annealing. An in-situ¬ laser heating set-up at a synchrotron beamline illustrates the very early-stage microstructural reorganisation inherent to high-temperature operation. Significant attention is directed throughout towards the extraction of reliable metrics, sampling a representative volume element and capturing evolution by digital volume correlation techniques. The expectation is that the developed methodology will provide insight into the necessary fabrication and operational parameters for maximising solid oxide fuel cell performance and durability. date: 2019-03-28 date_type: published oa_status: green full_text_type: other thesis_class: doctoral_open thesis_award: Ph.D language: eng thesis_view: UCL_Thesis primo: open primo_central: open_green verified: verified_manual elements_id: 1642074 lyricists_name: Bailey, Joshua lyricists_id: JBAIL07 actors_name: Waragoda Vitharana, Nimal actors_id: NWARR44 actors_role: owner full_text_status: public pagerange: 1-349 pages: 349 event_title: UCL (University College London) institution: UCL (University College London) department: Chemical Engineering thesis_type: Doctoral editors_name: Shearing, P editors_name: Brett, D editors_name: Atkinson, A citation: Bailey, Joshua James; (2019) Monitoring the Microstructural Evolution of Solid Oxide Fuel Cell Anodes. Doctoral thesis (Ph.D), UCL (University College London). Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10070734/1/PhD%20Thesis_Joshua%20James%20Bailey_2019.pdf