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dc.contributor.advisorBasu, Soumendra N.en_US
dc.contributor.authorLu, Yanchenen_US
dc.date.accessioned2019-08-14T18:27:12Z
dc.date.available2019-08-14T18:27:12Z
dc.date.issued2019
dc.identifier.urihttps://hdl.handle.net/2144/37096
dc.description.abstractSolid oxide fuel cells (SOFCs) are one of the most efficient and environment-friendly devices for electricity generation. One critical challenge of SOFC commercialization is high cell operating temperatures (800°C-1000°C), which lead to high material costs, high performance degradation rates, long start-up and shutdown times, and limited portable applications. Intermediate temperature (600°C-800°C) operation of SOFCs is limited by sluggish electrode reaction kinetics. The objective of this research is to improve intermediate temperature performance of commercially available Ni-YSZ cermet anode supported SOFCs by liquid infiltration of the anode. One effective method to improve kinetics of electrochemical reactions at the anode is to increase the density of reaction sites, which are known as the triple phase boundaries (TPBs). The porous Ni-YSZ cermet anodes were liquid infiltrated with Ni nanoparticles, leading to a four-fold increase in TPB density in the anode. The improved electrochemical performance of the infiltrated cells compared to the uninfiltrated cells highlights the effectiveness of anode infiltration in facilitating improved anode electrochemical reaction kinetics. However, the post-electrochemical testing characterization revealed that Ni nanoparticles were not stable due to Ni coarsening and were mostly isolated indicating that not all of the additional TPBs were fully utilized in electrochemical reactions due to the lack of an electronic pathway between the Ni nanoparticles. In order to improve microstructural stability of the infiltrated Ni nanoparticles, and to fully utilize the added TPBs, co-infiltration of Ni with a mixed ionic and electronic conductor (MIEC) was carried out. Two MIEC materials are chosen based on their chemical stability and conductivity in the anode operating environments; Gd0.1Ce0.9O2-δ (GDC), a predominantly an ionic conductor, and La0.6Sr0.3Ni0.15Cr0.85¬O3-δ (LSNC), a predominantly electronic conductor, and cells were successfully co-infiltrated to form Ni-GDC and Ni-LSNC nanostructures with the MIEC phases connecting the Ni nanoparticles. Stability tests demonstrated that both MIECs inhibited Ni nanoparticle coarsening. Electrochemical studies showed that Ni-GDC is the most effective for improved anode kinetics. A long-term (120 hours) electrochemical test indicated that infiltration of Ni-GDC into Ni-YSZ cermet anode effectively improves overall cell performance at intermediate temperatures and maintains the performance gain for a long period of time.en_US
dc.language.isoen_US
dc.rightsAttribution 4.0 Internationalen_US
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/
dc.subjectMaterials scienceen_US
dc.titleImproving intermediate temperature performance of NI-YSZ cermet anodes for solid oxide fuel cells by infiltration of nickel nanoparticles and mixed ionic electronic conductorsen_US
dc.typeThesis/Dissertationen_US
dc.date.updated2019-08-01T01:00:59Z
etd.degree.nameDoctor of Philosophyen_US
etd.degree.leveldoctoralen_US
etd.degree.disciplineMaterials Science & Engineeringen_US
etd.degree.grantorBoston Universityen_US


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Attribution 4.0 International
Except where otherwise noted, this item's license is described as Attribution 4.0 International