{"658829":{"#nid":"658829","#data":{"type":"event","title":"PhD Defense by Nicholas Kane","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003ETHE SCHOOL OF MATERIALS SCIENCE AND ENGINEERING\u003C\/strong\u003E\u202f\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u202f\u202f\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EGEORGIA INSTITUTE OF TECHNOLOGY\u003C\/strong\u003E\u202f\u202f\u202f\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u202f\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EUnder the provisions of the regulations for the degree\u003C\/strong\u003E\u0026nbsp;\u003Cbr \/\u003E\r\n\u202f\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EDOCTOR OF PHILOSOPHY\u003C\/strong\u003E\u0026nbsp;\u003Cbr \/\u003E\r\n\u202f\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003Eon Tuesday, July 12, 2022\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003E12:00 PM\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cbr \/\u003E\r\n\u003Cstrong\u003Evia\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ETeams Video Conferencing\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Ca href=\u0022https:\/\/teams.microsoft.com\/l\/meetup-join\/19%3ameeting_YmRjZGM2MDYtYjgwNS00YzMxLWI3MTgtNDlhOTc5NzQyNjJj%40thread.v2\/0?context=%7b%22Tid%22%3a%22482198bb-ae7b-4b25-8b7a-6d7f32faa083%22%2c%22Oid%22%3a%22c5ed8dba-fdb0-4e54-866f-e375184e86e8%22%7d\u0022\u003Ehttps:\/\/teams.microsoft.com\/l\/meetup-join\/19%3ameeting_YmRjZGM2MDYtYjgwNS00YzMxLWI3MTgtNDlhOTc5NzQyNjJj%40thread.v2\/0?context=%7b%22Tid%22%3a%22482198bb-ae7b-4b25-8b7a-6d7f32faa083%22%2c%22Oid%22%3a%22c5ed8dba-fdb0-4e54-866f-e375184e86e8%22%7d\u003C\/a\u003E\u202f\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003Ewill be held the\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u202f\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EDISSERTATION DEFENSE\u003C\/strong\u003E\u0026nbsp;\u003Cbr \/\u003E\r\n\u0026nbsp;\u003Cbr \/\u003E\r\n\u003Cstrong\u003Efor\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u202f\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ENicholas Kane\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u202f\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003E\u0026quot;Enhancing the Stability and Performance of Solid Oxide Cells by Tailoring Surfaces and Interfaces through Surface Modification\u0026quot;\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u202f\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ECommittee Members:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u202f\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EProf. Meilin Liu, Advisor, MSE\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EProf. Thomas Fuller, CHBE\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EProf. Mark Losego, MSE\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EProf. Matthew McDowell, ME\/MSE\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EProf. Preet Singh, MSE\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u202f\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EAbstract:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EReversible solid oxide cells (RSOCs) are an extremely promising solution for efficient electric grid storage. However, breakthroughs in materials innovation are required for RSOCs to be implemented on a large scale, as several challenges remain to be fully resolved. Wide spread use is limited by energy loss due to sluggish electrode reactions and inadequate durability of key materials for prolonged operation, causing increased system costs. The main goal of this work is to enhance the stability and performance of RSOCs through surface or interface modification within the cell.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe air electrode is one area of focus, as the kinetics of oxygen reduction and evolution reactions are notoriously sluggish, resulting in large overpotentials and low energy efficiency. Further, the problem is often exacerbated by reactions with contaminates commonly encountered in ambient air (e.g., H\u003Csub\u003E2\u003C\/sub\u003EO and CO\u003Csub\u003E2\u003C\/sub\u003E) and from other cell components (e.g., Cr), leading to degradation in performance over time. To combat these problems, a surface sol-gel (SSG) process was developed to achieve layer-by-layer deposition of catalytically active catalysts (e.g., PrO\u003Csub\u003Ex\u003C\/sub\u003E and BaO) on the surface of a porous air electrode, decreasing the polarization resistance and increasing the stability of the electrode. The advantages of the SSG process over conventional surface modification methods include excellent control of the composition, thickness, and uniformity of the coatings. In this dissertation, multiple different SSG coatings were investigated, including PrO\u003Csub\u003Ex\u003C\/sub\u003E, CeO\u003Csub\u003E2\u003C\/sub\u003E, BaO, and CoO\u003Csub\u003Ex\u003C\/sub\u003E. The deposition was validated with a quartz crystal microbalance to verify the linear addition of catalyst as a function of deposition cycles. The morphology of the coatings typically resembled numerous evenly dispersed particles across the electrode, as verified by SEM. Finally, the electrochemical performance of optimized coatings were investigated with electrochemical impedance spectroscopy and distribution of relaxation times. For PrO\u003Csub\u003Ex\u003C\/sub\u003E and BaO modifications, the polarization resistance was greatly reduced by the surface modification, as the catalysts effectively decreased the impedance of the ORR reactions. Ultimately, the PrO\u003Csub\u003Ex\u003C\/sub\u003E surface modification is demonstrated in YSZ-based single cells, increasing the peak power density from 0.32 to 0.46 W cm\u003Csup\u003E-2\u003C\/sup\u003E at 650 \u0026deg;C.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe interface between the electrolyte and the air electrode is the other area of focus, where the electrolyte experiences degradation due to exposure to high concentrations of water during water electrolysis. Here, a dense and highly stable electrolyte composition is deposited on the surface of a more conductive electrolyte prior to the application of the electrode, creating an electrolyte protection layer or bilayer electrolyte. BaHf\u003Csub\u003E0.8\u003C\/sub\u003EYb\u003Csub\u003E0.2\u003C\/sub\u003EO\u003Csub\u003E3\u003C\/sub\u003E (BHYb) is shown to be much more stable than the more conductive BaZr\u003Csub\u003E0.1\u003C\/sub\u003ECe\u003Csub\u003E0.7\u003C\/sub\u003EY\u003Csub\u003E0.1\u003C\/sub\u003EYb\u003Csub\u003E0.1\u003C\/sub\u003EO\u003Csub\u003E3-\u0026delta; \u003C\/sub\u003E(BZCYYb). Thus, a BHYb electrolyte protection layer was fabricated using co-sputtering, creating a BHYb\/BZCYYb bilayer electrolyte that offers significantly enhanced stability with little to no impact on electrochemical performance. An epitaxial, dense, and uniform BHYb layer is shown effective in preventing electrolyte degradation against high concentrations of steam and\u0026nbsp; CO\u003Csub\u003E2\u003C\/sub\u003E present in the air electrode, as confirmed by XRD, Raman spectroscopy, and SEM\/TEM analyses (no formation of a significant amount of barium carbonate). Finally BHYb\/BZCYYb bilayer-based single cells demonstrate state-of-the-art peak power densities of 1.64 W cm\u003Csup\u003E-2\u003C\/sup\u003E at 650 \u0026deg;C, which is among the highest ever reported for proton-conducting RSOCs. Additionally, the cells demonstrate excellent stability in the fuel cell, electrolysis, and reversible modes.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EOverall, this work demonstrated the power of surface modification in enhancing both performance and durability of reversible solid oxide cells. Modification of the air electrode surface improved the electrocatalytic activity for ORR while protecting the electrode from degradation. Similarly, modification of the electrolyte\/electrode interface protected the electrolyte from degradation in high concentrations of H\u003Csub\u003E2\u003C\/sub\u003EO and CO\u003Csub\u003E2\u003C\/sub\u003E. Thus, the performance and stability of RSOCs was improved by tailoring the properties of the surfaces and interfaces within the cell.\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"\u0022Enhancing the Stability and Performance of Solid Oxide Cells by Tailoring Surfaces and Interfaces through Surface Modification\u0022"}],"uid":"27707","created_gmt":"2022-06-13 15:20:02","changed_gmt":"2022-06-13 15:20:02","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2022-07-12T13:00:00-04:00","event_time_end":"2022-07-12T15:00:00-04:00","event_time_end_last":"2022-07-12T15:00:00-04:00","gmt_time_start":"2022-07-12 17:00:00","gmt_time_end":"2022-07-12 19:00:00","gmt_time_end_last":"2022-07-12 19:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78761","name":"Faculty\/Staff"},{"id":"78771","name":"Public"},{"id":"78751","name":"Undergraduate students"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}