2026-09-19T13:28:49Zhttps://dspace.mit.edu/server/oai/requestoai:dspace.mit.edu:1721.1/899852022-01-13T07:55:22Zcom_1721.1_7582com_1721.1_7581col_1721.1_131023
Gerbrand Ceder.
Lei, Yuechuan
Massachusetts Institute of Technology. Department of Materials Science and Engineering.
Massachusetts Institute of Technology. Department of Materials Science and Engineering
2014-09-19T21:32:41Z
2014-09-19T21:32:41Z
2014
2014
http://hdl.handle.net/1721.1/89985
890130367
Thesis: S.M., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2014.
Cataloged from PDF version of thesis. Page 53 blank.
Includes bibliographical references (pages 51-52).
A complete and uniform synthesis diagram of NaxCoO₂ has been proposed based on forty-one samples synthesized at various temperatures from 450°C to 750°C by solid-state reactions with initial Na:Co ratio ranging from 0.60 to 1.05. Four monophasic domains of' O3, O3', P3' and P2 and four biphasic regions were revealed based on an XRD analysis. The sodium contents in these phases were determined according to the d00j-x relations obtained by an in situ XRD experiment and it is found O3, O3' and P3' phase almost form with only one stoichiometry, that is x=1.00, 0.83 and 0.67 respectively, by solid-state reaction while P2 phase forms in a slightly larger composition range from 0.68 to 0.76. Galvanostatic charging on O3-Na₁.₀₀CoO₂ battery reveals several plateaus and steep steps on the voltage curve, the corresponding phase transitions and solid solution behaviors were studied by a simultaneous in situ XRD experiment. The composition driven structural evolution in three layer NaXCoO₂ follows the sequence: O3-O3'-P3'-P3-P3', with a generally increased interslab distance d₀₀l.
by Yuechuan Lei.
S.M.
53 pages
eng
Massachusetts Institute of Technology
M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.
http://dspace.mit.edu/handle/1721.1/7582
Materials Science and Engineering.
Determination of the synthesis diagram of sodium cobalt oxide and electrochemical study
Thesis
application/pdf
false
Publication
unknown
unknown
<Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="0cbb693d-79a3-4b0d-b2dc-e54b308e3c7b">
<Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type>
<Language>eng</Language>
<Title>Determination of the synthesis diagram of sodium cobalt oxide and electrochemical study</Title>
<PublishedIn>
<Publication>
</Publication>
</PublishedIn>
<PublicationDate>2014</PublicationDate>
<Authors>
<Author>
<DisplayName>Lei, Yuechuan</DisplayName>
<Affiliation>
<OrgUnit>
</OrgUnit>
</Affiliation>
</Author>
</Authors>
<Editors>
</Editors>
<Publishers>
<Publisher>
<DisplayName>Massachusetts Institute of Technology</DisplayName>
<OrgUnit />
</Publisher>
</Publishers>
<License>http://dspace.mit.edu/handle/1721.1/7582</License>
<Keyword>Materials Science and Engineering.</Keyword>
<Abstract>A complete and uniform synthesis diagram of NaxCoO₂ has been proposed based on forty-one samples synthesized at various temperatures from 450°C to 750°C by solid-state reactions with initial Na:Co ratio ranging from 0.60 to 1.05. Four monophasic domains of' O3, O3', P3' and P2 and four biphasic regions were revealed based on an XRD analysis. The sodium contents in these phases were determined according to the d00j-x relations obtained by an in situ XRD experiment and it is found O3, O3' and P3' phase almost form with only one stoichiometry, that is x=1.00, 0.83 and 0.67 respectively, by solid-state reaction while P2 phase forms in a slightly larger composition range from 0.68 to 0.76. Galvanostatic charging on O3-Na₁.₀₀CoO₂ battery reveals several plateaus and steep steps on the voltage curve, the corresponding phase transitions and solid solution behaviors were studied by a simultaneous in situ XRD experiment. The composition driven structural evolution in three layer NaXCoO₂ follows the sequence: O3-O3'-P3'-P3-P3', with a generally increased interslab distance d₀₀l.</Abstract>
<Access xmlns="http://purl.org/coar/access_right"
>
</Access>
</Publication>