{"658717":{"#nid":"658717","#data":{"type":"event","title":"PhD Defense by Weilin Zhang","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003ETHE SCHOOL OF MATERIALS SCIENCE AND ENGINEERING\u003C\/strong\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EGEORGIA INSTITUTE OF TECHNOLOGY\u003C\/strong\u003E\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EUnder the provisions of the regulations for the degree\u003Cbr \/\u003E\r\n\u0026nbsp;\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EDOCTOR OF PHILOSOPHY\u003C\/strong\u003E\u003Cbr \/\u003E\r\n\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003Eon Monday, June 20, 2022\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003E10:00 AM\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003Evia\u003C\/strong\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\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\u0026nbsp;\u003Ca href=\u0022https:\/\/teams.microsoft.com\/l\/meetup-join\/19%3ameeting_YzZmYzEyMWItZmVlNS00NjQ5LTlkZjUtMTVlMWEyMzg2ZDg3%40thread.v2\/0?context=%7b%22Tid%22%3a%22482198bb-ae7b-4b25-8b7a-6d7f32faa083%22%2c%22Oid%22%3a%226b09eaa2-9834-4cee-8e16-df9d99805556%22%7d\u0022\u003Ehttps:\/\/teams.microsoft.com\/l\/meetup-join\/19%3ameeting_YzZmYzEyMWItZmVlNS00NjQ5LTlkZjUtMTVlMWEyMzg2ZDg3%40thread.v2\/0?context=%7b%22Tid%22%3a%22482198bb-ae7b-4b25-8b7a-6d7f32faa083%22%2c%22Oid%22%3a%226b09eaa2-9834-4cee-8e16-df9d99805556%22%7d\u003C\/a\u003E\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\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EDISSERTATION\u0026nbsp;DEFENSE\u003C\/strong\u003E\u003Cbr \/\u003E\r\n\u003Cbr \/\u003E\r\n\u003Cstrong\u003Efor\u003C\/strong\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EWeilin Zhang\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003E\u0026nbsp;\u0026nbsp;\u0026ldquo;Development of Novel Electrode and Catalyst Materials for Solid Oxide Electrochemical Cells\u0026rdquo;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ECommittee Members:\u0026nbsp;\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\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. Preet Singh, MSE\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EProf. Hamid Garmestani, MSE\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EProf. Faisal Alamgir, 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\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\u003ESolid oxide electrochemical cell (SOC), which offers a promising solution to a sustainable energy future, is a class of solid-state electrochemical devices for efficient energy storage and conversion. A SOC can operate on the fuel cell mode (solid oxide fuel cell, SOFC) to generate electricity from hydrogen or hydrocarbon fuels. It can also operate on the electrolysis cell mode (solid oxide electrolysis cell, SOEC) to produce valuable fuels by electrolyzing water or carbon dioxide. This dissertation focuses on the development of novel electrode, catalyst, and fabrication techniques for SOCs. The overall study can be separated into four parts.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe first study focuses on the development of active and durable air electrode material for intermediate-temperature reversible solid oxide cells. To achieve high round-trip efficiency of SOCs, highly efficient and durable air electrode materials are needed to minimize energy loss associated with oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Here we report a bifunctional air electrode material, PrBa\u003Csub\u003E0.9\u003C\/sub\u003ECo\u003Csub\u003E1.96\u003C\/sub\u003ENb\u003Csub\u003E0.04\u003C\/sub\u003EO\u003Csub\u003E5+\u0026delta;\u003C\/sub\u003E, demonstrating outstanding electrochemical performance (e.g., achieving peak power densities of over 1.5 and 1 W cm\u003Csup\u003E\u0026minus;2\u003C\/sup\u003E, respectively, for Gd\u003Csub\u003E0.1\u003C\/sub\u003ECe\u003Csub\u003E0.9\u003C\/sub\u003EO\u003Csub\u003E1.95\u003C\/sub\u003E and 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\u003Ebased fuel cells at 600 \u0026ordm;C) while maintaining excellent stability (e.g., having a degradation rate of 40 mV per 1,000 h for H\u003Csub\u003E2\u003C\/sub\u003EO electrolysis cells). The excellent property of the new electrode is attributed to the improved stability from Nb doping and the enhanced electrocatalytic activity from tuning Ba deficiency, as confirmed by experimental results and computational analysis.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EFollowing the first study, to lower the operating temperature of SOC, the second study focuses on the development of triple conducting air electrode materials for low-temperature dual-ion conducting fuel cells. A series of materials candidates were designed by heavily doping transition metal and rare earth metal into BaHf\u003Csub\u003E0.8\u003C\/sub\u003EY\u003Csub\u003E0.2\u003C\/sub\u003EO\u003Csub\u003E3-\u0026delta;\u003C\/sub\u003E-based electrolyte material. The optimized composition Ba\u003Csub\u003E0.9\u003C\/sub\u003EPr\u003Csub\u003E0.1\u003C\/sub\u003EHf\u003Csub\u003E0.1\u003C\/sub\u003EY\u003Csub\u003E0.1\u003C\/sub\u003ECo\u003Csub\u003E0.8\u003C\/sub\u003EO\u003Csub\u003E3-\u0026delta; \u003C\/sub\u003Edemonstrates an outstanding electrochemical activity on both 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 based symmetrical cells and single cells. X-ray diffraction and transmission electron microscopy results confirm that BPHYC is a mixture of three different phases, consisting of Y doped BaCoO\u003Csub\u003E3-\u0026delta; \u003C\/sub\u003E(BYC), PrBaCo\u003Csub\u003E2\u003C\/sub\u003EO\u003Csub\u003E5+\u0026delta; \u003C\/sub\u003E(PBC), and Y doped BaHfO\u003Csub\u003E3-\u0026delta;\u003C\/sub\u003E (BHY). Detailed electrochemical analysis unravels that BYC and PBC phases play a synergistic effect on the ORR kinetics on oxygen-ion conducting cells, and BHY contributes to the catalytic activity on proton-conducting cells. The triple conductivity of BPHYC was evaluated by the electrical conductivity relaxation measurement and the isotope exchange diffusion profile measurement. The long-term stability of BPHYC was also confirmed on both symmetrical cells and single cells under typical operating conditions.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EFor the fuel electrode development, the third study focuses on the development of anode catalyst materials for SOFCs operated on hydrocarbon fuels. Conventional Ni-based cermet anode suffers from the coking issue when the hydrocarbon is used as the fuel. In this study, I designed and synthesized Ni and Ru co-doped BaZr\u003Csub\u003E0.8\u003C\/sub\u003EY\u003Csub\u003E0.2\u003C\/sub\u003EO\u003Csub\u003E3-\u0026delta;\u003C\/sub\u003E (BZYNR) as a promising anode catalyst material for SOFCs operated on various hydrocarbon fuels.\u0026nbsp; When applied BZYNR on button cells with a conventional Ni-based anode, the single cells can operate on wet iso-octane (with 3 vol% H\u003Csub\u003E2\u003C\/sub\u003EO) for over 1,000 hours without obvious coking behavior. BZYNR was further applied on large-scale tubular cells with an effective area of about 38 cm\u003Csup\u003E2\u003C\/sup\u003E. World-record power output and durability were demonstrated on iso-octane, ethanol, and methane fuels. Two key properties of BZYNR contributed to its outstanding performance. First is that Ni and Ru cations are highly active sites for the hydrocarbon reforming process. The second is that BZYNR shows good water absorption capability, which benefits the water-mediated carbon removal process.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe fourth study focuses on the fabrication techniques to create nanostructured electrodes for SOFCs. Durable, nanostructured electrodes fabricated via a simple, cost-effective method is effective to solve the performance and durability issues for SOFCs. In this work, both the nanostructured PrBa\u003Csub\u003E0.5\u003C\/sub\u003ESr\u003Csub\u003E0.5\u003C\/sub\u003ECo\u003Csub\u003E1.5\u003C\/sub\u003EFe\u003Csub\u003E0.5\u003C\/sub\u003EO\u003Csub\u003E5+\u0026delta;\u003C\/sub\u003E (PBSCF) cathode and Ni\u0026minus;Ce\u003Csub\u003E0.8\u003C\/sub\u003ESm\u003Csub\u003E0.2\u003C\/sub\u003EO\u003Csub\u003E1.9\u003C\/sub\u003E (SDC) anode are fabricated on porous yttria-stabilized zirconia (YSZ) backbone via solution infiltration. Symmetrical cells with a configuration of PBSCF|YSZ|PBSCF show a low interfacial polarization resistance of 0.03 \u0026Omega; cm\u003Csup\u003E2\u003C\/sup\u003E with minimal degradation at 700 \u0026deg;C for 600 h. Ni-SDC|YSZ|PBSCF single cells exhibit a peak power density of 0.62 W cm\u003Csup\u003E\u0026minus;2\u003C\/sup\u003E at 650 \u0026deg;C operated on H\u003Csub\u003E2\u003C\/sub\u003E with good thermal cycling stability for 110 h. Single cells also show excellent coking tolerance with stable operation on CH\u003Csub\u003E4\u003C\/sub\u003E for over 120 h. This work offers a promising pathway toward the development of high-performance and durable SOFCs to be powered by natural gas.\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"  \u201cDevelopment of Novel Electrode and Catalyst Materials for Solid Oxide Electrochemical Cells\u201d     "}],"uid":"27707","created_gmt":"2022-06-06 19:25:39","changed_gmt":"2022-06-06 19:25:39","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2022-06-20T11:00:00-04:00","event_time_end":"2022-06-20T13:00:00-04:00","event_time_end_last":"2022-06-20T13:00:00-04:00","gmt_time_start":"2022-06-20 15:00:00","gmt_time_end":"2022-06-20 17:00:00","gmt_time_end_last":"2022-06-20 17:00:00","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":""}}}