Is it possible to prepare olivine-type LiFeSiO 4?
Silicates LiMSiO 4 are potential positive electrode materials for lithium ion batteries. In this work we analyse from first principles calculations the relative stability of possible LiFeSiO 4-polymorphs within four structural types. Olivine-LiFeSiO 4 is predicted to be more stable than the LiFeSiO...
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Published in | Solid state ionics Vol. 179; no. 27; pp. 1758 - 1762 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Elsevier B.V
2008
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Subjects | |
Online Access | Get full text |
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Summary: | Silicates LiMSiO
4 are potential positive electrode materials for lithium ion batteries. In this work we analyse from first principles calculations the relative stability of possible LiFeSiO
4-polymorphs within four structural types. Olivine-LiFeSiO
4 is predicted to be more stable than the LiFeSiO
4 prepared by delithiation of Li
2FeSiO
4; the latter being the only LiFeSiO
4 compound reported so far. Attempts to prepare olivine-LiFeSiO
4 from a mixture of reactants at ambient pressure (600–1100 °C) resulted in a mixture of quartz-SiO
2, Li
2SiO
3, LiFe
5O
8 and LiFeSi
2O
6 phases. Conducting the reaction under HP conditions (40 kbar) leads to the formation of LiFeSi
2O
6 as a majority phase, regardless the nature of the reactants/precursors. First principles calculations indicate that the preparation of the olivine-LiFeSiO
4 is thermodynamically hindered due to the competition with the more stable LiFeSi
2O
6 pyroxene, in the range of pressure/temperature investigated. |
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ISSN: | 0167-2738 1872-7689 |
DOI: | 10.1016/j.ssi.2008.03.023 |