Show simple item record

dc.contributor.advisorLee, Sang Boken_US
dc.contributor.authorHu, Junkaien_US
dc.date.accessioned2015-09-18T05:59:35Z
dc.date.available2015-09-18T05:59:35Z
dc.date.issued2015en_US
dc.identifierhttps://doi.org/10.13016/M2TH1N
dc.identifier.urihttp://hdl.handle.net/1903/17088
dc.description.abstractThe combination of high electronic conductivity, enhanced ionic mobility, and large pore volume make ordered mesoporous carbons (OMCs) promising scaffolds for active energy storage materials. However, mesoporous structures and material morphology need to be more thoroughly addressed. This dissertation discusses the effects of mesoporous structures and material morphologies on the electrochemical performance of OMC/Fe2O3 composites. In the first approach, Fe2O3 was embedded into 1D cylindrical (FDU-15), 2D hexagonal (CMK-3), and 3D bicontinuous (CMK-8) symmetries of mesoporous carbons. These materials were used as supercapacitors for a systematic study of the effects of mesoporous architecture on the structure stability, ion mobility, and performance of mesoporous composite electrodes. The results show that the CMK-3 and CMK-8 synthesized by hard template method can provide high pore volume, but the instability of their mesostructures hinders the total electrode performances upon oxide impregnation. In contrast, the FDU-15 from the soft template method can provide a stable mesostructure. However, it contains much smaller pore volume and surface area, leading to limited metal oxide loading and electrode capacitance. Based on these results, anodized aluminum oxide (AAO) and triblock copolymer F127 are used together as hard and soft templates to fabricate ordered mesoporous carbon nanowires (OMCNW) as a host material for Fe2O3 nanoparticles. The synergistic effects in the dual template strategy provide a high pore volume and surface area, and the structure remains stable even with high metal oxide loading amounts. Additionally, the unique nanowire morphology and mesoporous structure of the OMCNW/Fe2O3 facilitate high ionic mobility in the composite, leading to a large capacitance with good rate capability and cycling stability. I further evaluated this OMCNW/Fe2O3 as a lithium-ion battery (LIB) anode, which showed that the porous symmetry, material morphology, and structure stability are even more important in the rate and cycling performances of LIBs. This work helps further the understanding and optimization of porous structures and morphologies of heterogeneous composites for next generation electrochemical energy storage materials.en_US
dc.language.isoenen_US
dc.titleHeterogeneous Ordered Mesoporous Carbon/Metal Oxide Composites for the Electrochemical Energy Storageen_US
dc.typeDissertationen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.contributor.departmentChemistryen_US
dc.subject.pqcontrolledChemistryen_US
dc.subject.pquncontrolledcarbonen_US
dc.subject.pquncontrollediron oxideen_US
dc.subject.pquncontrolledlithium ion batteryen_US
dc.subject.pquncontrolledmesoporousen_US
dc.subject.pquncontrollednanowireen_US
dc.subject.pquncontrolledsupercapacitoren_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record