Thermal, Electrical, and Electrochemical Characterizations of Advanced Nanomaterials for Energy Conversion and Storage Applications
Digital Document
Document
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Handle
http://hdl.handle.net/11134/20002:860653671
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Persons |
Persons
Creator (cre): Yazdani, Sajad
Major Advisor (mja): Pettes, Michael T.
Associate Advisor (asa): Pasaogullari, Ugur
Associate Advisor (asa): Chiu, Wilson K.S.
Associate Advisor (asa): Dutta, Niloy
Associate Advisor (asa): Lee, Jason
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Title |
Title
Title
Thermal, Electrical, and Electrochemical Characterizations of Advanced Nanomaterials for Energy Conversion and Storage Applications
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Origin Information
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Parent Item
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Resource Type
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Digital Origin |
Digital Origin
born digital
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Description |
Description
This work is concerned with the leading methods of bottom-up material synthesis and characterization for electrochemical storage as well as thermal-to-electrical energy interconversion. Among various metal oxides, manganese oxide-based materials are very attractive for electrochemical applications due to being abundant, especially anode applications in lithium ion batteries. The main issues hindering the effective use of manganese oxides are their ultra-high electrical resistivity, and phase instability during cycling. These issues are addressed by a purposeful use of controlled growth on multiwalled carbon nanotubes and Co-alloying. The presence of oxygen vacancy sites fundamentally affects physical and chemical properties of materials. It is reported that a thermochemical interaction between poly(diallyldimethylammonium chloride) PDDA and α-MoO3 enables formation of highconcentrations of oxygen vacancies. A proposed mechanism suggests that the vacancy sites are created through absorption of terminal site oxygen (Ot) upon decomposition of the N─C bond in the pentagonal ring of PDDA during the thermal treatment. Ot atoms are absorbed as ionic O- and neutral O2- , creating Mo5+-vO · and Mo4+-vO ··vacancy bipolarons and polarons, respectively. Samples with higher concentrations of oxygen vacancies are found to be more active for oxygen reduction reaction. Furthermore, high temperature energy conversion materials, such as PbS, are very attractive for waste heat recovery from a thermodynamic stand point. However, chemistry of bottom-up methods can be quite complicated and introduce vacancies sites and defects leading to uncontrolled chemical potentials and charged interfaces altering the electronic transport properties of PbS. It is shown that the electronic transport is dominated by the existence of trap states and dramatic effects of highly charged interfaces on electro-thermal properties of PbS1-x have been investigated. Finally, thermal, electrical and electrochemical materials property measurements can be quite challenging especially at high temperatures introducing significant uncertainty. In this thesis, an instrument design for consecutive and accurate measurements of thermal conductivity, electrical conductivity, and ionic conductivity as well as Seebeck coefficient within a wide range of temperatures is presented by eliminating potential sources of error.
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Genre
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Organizations |
Organizations
Degree granting institution (dgg): University of Connecticut
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Rights Statement |
Rights Statement
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Use and Reproduction |
Use and Reproduction
These materials are provided for educational and research purposes only.
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Note
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Local Identifier |
Local Identifier
OC_d_1851
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