Pasero, D., Reeves, N., Gillie, Lisa .J., Pralong, V. and West, Anthony R. (2007) Oxygen stoichiometry-structure-property correlations in Li2/3[Mn2/3Ni1/3]O2−δ with O3 structure. Journal of the Electrochemical Society, 154 (8). A760-A769. ISSN 0013-4651Metadata only available from this repository.
The layered rock salt material Li2/3[Mn2/3Ni1/3]O2− with the O3 structure loses up to 16 % of its oxygen reversibly at high temperature. It transforms initially to a second layered structure, O3, that may be associated with cooperative Jahn-Teller distortion of Mn3+ ions and considerable interlayer cation mixing. By continuous disordering and further oxygen loss, it finally transforms into a simple cubic rock salt structure above 1000°C, as shown by thermogravimetry and high-temperature X-ray powder diffraction. X-ray absorption near-edge structure results confirm that oxygen deficiency induces reduction of mainly Mn and to a small extent Ni, commencing with the fully oxidized stoichiometry Li2/3[MnNi]O2. This correlates with oxygen contents determined by thermogravimetry and Rietveld refinement of powder X-ray diffraction data, with oxidation states determined by chemical titration and with electrochemical behavior during cycling. The cycling results show that samples with the O2 structure have better performance and capacity than those with O3 and especially O3 structures and that the O3, O3 capacity decreases with increasing oxygen deficiency .
|Additional Information:||© 2008 The Electrochemical Society; all rights reserved|
|Subjects:||Q Science > QD Chemistry|
|Schools:||School of Applied Sciences
School of Applied Sciences > Materials and Catalysis Research Centre
|Depositing User:||Briony Heyhoe|
|Date Deposited:||30 May 2008 13:29|
|Last Modified:||12 Jan 2011 11:32|
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