Long-range ordering during delithiation of LiMn2O4 cathode material
(2003) In Journal of Materials Chemistry 13(3). p.585-589- Abstract
A single crystal of the cubic spinel LiMn2O4 was delithiated electrochemically at 4.06 V vs. Li/Li+ to probe the structural source of the inflection point at ca. 4.1 V vs. Li/Li+ in the discharge curve. The phase thus obtained was investigated by single-crystal X-ray diffraction and the structure refined. The structure is closely related to the original cubic structure, but the new space group is rhombohedral R3̄m and shows a one-dimensional modulation along the <001>r direction with wave vector q ≈ 0.75c*. The cell parameters are: a = 5.762(1) Å and c = 14.080(4), and the (3 + 1)-dimensional super space group is R3̄m(00γ). The modulated phase involves two unique Mn atoms with... (More)
A single crystal of the cubic spinel LiMn2O4 was delithiated electrochemically at 4.06 V vs. Li/Li+ to probe the structural source of the inflection point at ca. 4.1 V vs. Li/Li+ in the discharge curve. The phase thus obtained was investigated by single-crystal X-ray diffraction and the structure refined. The structure is closely related to the original cubic structure, but the new space group is rhombohedral R3̄m and shows a one-dimensional modulation along the <001>r direction with wave vector q ≈ 0.75c*. The cell parameters are: a = 5.762(1) Å and c = 14.080(4), and the (3 + 1)-dimensional super space group is R3̄m(00γ). The modulated phase involves two unique Mn atoms with coordination polyhedra which differ significantly: one has an average Mn-O distance of 2.24(1) Å, indicative of a lower oxidation state for the Mn ion; the other has an average Mn-O distance of. 1.82(2) Å, indicative of a higher oxidation state. Lithium ions appear to be extracted from the structure in a long-range-ordered two-dimensional arrangement between the cubic-close-packed oxygen layers; the manganese atoms are also arranged in charge-ordered Mn3+/Mn4+ sheets. These two features are the source of the modulation in the structure.
(Less)
- author
- Björk, Helen ; Gustafsson, Torbjörn ; Thomas, John O. ; Lidin, Sven LU and Petříček, Václav
- publishing date
- 2003-03-01
- type
- Contribution to journal
- publication status
- published
- in
- Journal of Materials Chemistry
- volume
- 13
- issue
- 3
- pages
- 5 pages
- publisher
- Royal Society of Chemistry
- external identifiers
-
- scopus:0037338505
- ISSN
- 0959-9428
- DOI
- 10.1039/b210265j
- language
- English
- LU publication?
- no
- id
- 34ebbba0-37a8-4ecf-9ede-0173182642e2
- date added to LUP
- 2019-04-08 15:33:41
- date last changed
- 2022-01-31 18:51:58
@article{34ebbba0-37a8-4ecf-9ede-0173182642e2, abstract = {{<p>A single crystal of the cubic spinel LiMn<sub>2</sub>O<sub>4</sub> was delithiated electrochemically at 4.06 V vs. Li/Li<sup>+</sup> to probe the structural source of the inflection point at ca. 4.1 V vs. Li/Li<sup>+</sup> in the discharge curve. The phase thus obtained was investigated by single-crystal X-ray diffraction and the structure refined. The structure is closely related to the original cubic structure, but the new space group is rhombohedral R3̄m and shows a one-dimensional modulation along the <001><sub>r</sub> direction with wave vector q ≈ 0.75c*. The cell parameters are: a = 5.762(1) Å and c = 14.080(4), and the (3 + 1)-dimensional super space group is R3̄m(00γ). The modulated phase involves two unique Mn atoms with coordination polyhedra which differ significantly: one has an average Mn-O distance of 2.24(1) Å, indicative of a lower oxidation state for the Mn ion; the other has an average Mn-O distance of. 1.82(2) Å, indicative of a higher oxidation state. Lithium ions appear to be extracted from the structure in a long-range-ordered two-dimensional arrangement between the cubic-close-packed oxygen layers; the manganese atoms are also arranged in charge-ordered Mn<sup>3+</sup>/Mn<sup>4+</sup> sheets. These two features are the source of the modulation in the structure.</p>}}, author = {{Björk, Helen and Gustafsson, Torbjörn and Thomas, John O. and Lidin, Sven and Petříček, Václav}}, issn = {{0959-9428}}, language = {{eng}}, month = {{03}}, number = {{3}}, pages = {{585--589}}, publisher = {{Royal Society of Chemistry}}, series = {{Journal of Materials Chemistry}}, title = {{Long-range ordering during delithiation of LiMn<sub>2</sub>O<sub>4</sub> cathode material}}, url = {{http://dx.doi.org/10.1039/b210265j}}, doi = {{10.1039/b210265j}}, volume = {{13}}, year = {{2003}}, }