Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Hydrothermal synthesis and characterization of LiMnPO4 for secondary lithium batteries /
Download
index.pdf
Date
2014
Author
Camcı, Esin
Metadata
Show full item record
Item Usage Stats
207
views
129
downloads
Cite This
The mechanism in Li-ion batteries is based on the motion of Li+ ion between positive and negative electrodes. As Li-ion batteries have attracted much attention, the demand for high capacity and low cost electrode materials has increased. Lithium manganese phosphate (LMnP) is one of the most promising cathode materials. It highly satisfies the lithiation and de-lithiation process of Li-ion technology due to its olivine structure. Moreover, it has high theoretical capacity, it is safety and low cost. The drawback of LMnP is its poor ionic and electronic conductivity. The aim of this thesis is to optimize the hydrothermal process parameters for the synthesis of pure and well-crystalline LMnP, dope the Mn-site in the olivine structure with cobalt, chromium, molybdenum, vanadium and tungsten and eventually electrochemically characterize the samples to analyze the effect of doping. The structure and topography of the obtained powders were investigated with X-Ray Diffraction and Scanning Electron Microscopy. Also, the electrochemical characteristics were determined by different techniques; cycle tests, charge-discharge, Cyclic Voltammetry and Electrochemical Impedance Spectroscopy. According to the results, doping process was successful to show better performance than pristine LMnP. After pure LMnP and its doped versions were analyzed, it is understood that cobalt and vanadium enhances the electrical and ionic conductivity of LMnP; whereas, chromium has an influence on the rate capability of LMnP
Subject Keywords
Lithium cells.
,
Cathodes.
,
Electrodes.
,
Electrochemistry.
,
Electric conductivity.
URI
http://etd.lib.metu.edu.tr/upload/12617926/index.pdf
https://hdl.handle.net/11511/24077
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Extraction Using Moderate Electric Fields
Şensoy, İlkay (2004-01-01)
During moderate electric field (MEF) processing, a voltage applied across a food material may affect the permeability of cell membranes. It is known that high electric fields can cause either reversible or irreversible rupture of cell membranes. In this research, the effect of MEF processing on permeability was studied. Effects of frequency and electric field strength were investigated. Cellular structure was investigated by transmission electron microscopy (TEM). Fermented black tea leaves and fresh or dry...
Residual stress and Young's modulus measurement of capacitive micromachined ultrasonic transducer membranes
Yaralioglu, GG; Ergun, AS; Bayram, Barış; Marentis, T; Khuri-Yakub, BT (2001-01-01)
Membranes supported by posts are used as vibrating elements of capacitive micromachined ultrasonic transducers (CMUTs). The residual stress built up during the fabrication process determines the transducer properties such as resonance frequency, collapse voltage, and gap distance. Hence, it is important to evaluate and control the stress in thin film CMUT membranes. The residual stress in the membrane causes significant vertical displacements at the center of the membrane. The stress bends the membrane post...
SENSITIVITY ENHANCEMENT FOR SLOTTED QUARTZ TUBE FLAME ATOMIC ABSORPTION SPECTROMETRY USING A GAS SCREEN
Gholami, Mehrdad; Farjoud, Mohammad Javad; Sepehri, Masoud; Nazari, Ammar; Gholami, Majid; Behkami, Shima; Ataman, Osman Yavuz (2011-01-01)
Slotted Quartz Tube (SQT) is a simple device that provides a sensitivity enhancement of 2-5 times in Flame Atomic Absorption Spectrometry (FAAS) depending on the element. A Gas Screen-Slotted Quartz Tube (GS-SQT) was designed to further increase sensitivity. For this purpose, two slotted gas chambers were fixed on the left and right sides of a burner head and Ar gas was supplied into these chambers perpendicular to the light path to produce two thin layers of gas screen. It was observed that these Ar screen...
Silver nanowire networks on polydimethylsiloxane for organic and perovskite solar cell electrodes
Güner, Elif Özlem; Ünalan, Hüsnü Emrah; Department of Metallurgical and Materials Engineering (2019)
Transparent and conductive electrodes are widely used in optoelectronic devices. The most prominent and commercial transparent conductive electrode is indium tin oxide (ITO). However, there is an increasing demand to replace ITO with alternative materials due to inherent drawbacks of ITO such as its cost, brittleness and scarcity of indium. Silver nanowire (Ag NW) networks are among the best candidates to replace ITO with their excellent optoelectronic and mechanical properties. Ag NW networks have already ...
Differential charging in SiO2/Si system as determined by XPS
Karadas, F; Ertaş, Gülay; Suzer, S (American Chemical Society (ACS), 2004-01-29)
The Si2p binding and the Si-KLL kinetic energy difference between the SiO2 layer and Si substrate is shown to be influenced by application of external voltage bias to the sample holder due to the differential charging as was already reported earlier (Ulgut, B.; Suzer, S. J. Phys. Chem. B 2003, 107, 2939). The cause of this bias induced (physical)-shift is now proven to be mostly due to partial neutralization by the stray electrons within the vacuum system by (i) introducing additional stray electrons via a ...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
E. Camcı, “Hydrothermal synthesis and characterization of LiMnPO4 for secondary lithium batteries /,” M.S. - Master of Science, Middle East Technical University, 2014.