uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Structural changes on cycling Li 2FeSiO 4 polymorphs from DFT calculations
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
2012 (English)In: Solid State Ionics, ISSN 0167-2738, E-ISSN 1872-7689, Vol. 228, 19-24 p.Article in journal (Refereed) Published
Abstract [en]

Cation mixing has been demonstrated experimentally in the Li-ion battery cathode material Li 2FeSiO 4. This feature is investigated here using DFT calculations. It is shown that full reversal of Li/Fe site occupations is energetically favoured on delithiation for all three electrochemically active Li 2FeSiO 4 polymorphs. The common layered topology in the arrangement of SiO 4 and FeO 4 tetrahedra in all three polymorphs transforms into a 3D-framwork. Calculations show here that such a change in structure leads to a lowering of electrochemical insertion potential from ~ 3.1 to ~ 2.8 V, in good agreement with experimental data. Calculations also predict the correct anisotropy in the cell expansion on delithiation on Li/Fe site reversals. Partial mixing of Li and Fe site occupations is energetically less favourable, which supports a two-phase transformation mechanism.

Place, publisher, year, edition, pages
2012. Vol. 228, 19-24 p.
Keyword [en]
Crystal structure, Density functional theory, Lithium iron silicate, Solid state electrochemistry
National Category
Natural Sciences
URN: urn:nbn:se:uu:diva-188115DOI: 10.1016/j.ssi.2012.08.016ISI: 000312522800004OAI: oai:DiVA.org:uu-188115DiVA: diva2:576669
Available from: 2012-12-13 Created: 2012-12-12 Last updated: 2013-01-22Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Liivat, Anti
By organisation
Structural Chemistry
In the same journal
Solid State Ionics
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 326 hits
ReferencesLink to record
Permanent link

Direct link