Development and characterization of high energy cathode materials for lithium-ion batteries

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2013

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Büyükburç, Atıl

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The aim of this thesis is to produce high energy cathode materials based on LiCoO2 materials with the general formula LiCo1-xMxO2 and LiCo1-y-xMxNyO2. In order to achieve this formula, less exploited doping elements such as Mo, Cr and W will be used as well as Mn. During the study, the parameters of the processes which are solution preparation, freeze drying and calcination are optimized. According to the results, 24 hours of freeze drying is enough for drying the samples. Calcination at lower (< 700°C) temperatures as well as higher temperatures (> 800°C) do not yield single phase LiCoO2. It is also determined that, holding pH around 10.75 and Li:Co ratio are very important for having single phase LiCoO2. XRD, SEM and SEM-EDX are used for structural analyses. ICP and XPS are used for chemical analysis. For electrochemical characterization, galvanostatic charge-discharge tests, CV and EIS are applied. The results have shown that the sample containing 1 mole% W and 1 mole% Mn has the best electrochemical performance among the other samples. The reason for the electrochemical superiority of this sample is due to the different surface chemistry.

Subject Keywords

Lithium cells., Cathodes., Electrodes., Electric batteries., Surface chemistry., Freeze-drying.

URI

http://etd.lib.metu.edu.tr/upload/12616122/index.pdf
https://hdl.handle.net/11511/22834

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Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

A. Büyükburç, “Development and characterization of high energy cathode materials for lithium-ion batteries,” Ph.D. - Doctoral Program, Middle East Technical University, 2013.