Synthesis and thermoelectric characterization of Ca3Co4O9 particles

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Date

2018

Author

Ertuğrul, Hediye Merve

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Thermoelectric materials can convert waste heat to electrical energy as well as thermal energy to electrical energy. Thermoelectric technology can aid to solve the energy problem which causes global environmental problems as an alternative energy source and provide long-lasting power sources which can be used for space missions. Ca3Co4O9 is environment friendly, nontoxic, humidity resistant at high temperatures, oxidation resistant, abundant, chemically and thermally stable in air and light. Also, this material is favored because of its natural layered structure which provides high ZT value. Ultrasonic spray pyrolysis method is used for obtaining hollow spherical particles. Thanks to pressure-less sintering method, high amount of porosity in the pellets can be achieved. The aim of this study is that increasing power factor and decreasing thermal conductivity simultaneously through hollow spherical Ca3Co4O9 and air composite materials. Hollow spherical particles which are filled with air having low thermal conductivity and the surface of particles which is about 2D and compose of nanoscale constituents provide low thermal conductivity and high power factor. The powders will be characterized using X-ray diffraction, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and particle size analysis for structural analysis. The temperature dependence of Seebeck coefficient and electrical resistivity will be measured using a lab-made system set up in our laboratory in the temperature interval from 300 K to 900 K.

Subject Keywords

Thermoelectricity., Pyrolysis., Oxides.

URI

http://etd.lib.metu.edu.tr/upload/12622607/index.pdf
https://hdl.handle.net/11511/27542

Collections

Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

H. M. Ertuğrul, “Synthesis and thermoelectric characterization of Ca3Co4O9 particles,” M.S. - Master of Science, Middle East Technical University, 2018.