Crystal chemistry of the Pmnb polymorph of Li{sub 2}MnSiO{sub 4}

Journal Article · Sun Apr 15 04:00:00 EDT 2012 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2012.01.051· OSTI ID:22012085

Sharma, N; Peterson, V K ^[1]; He, Y ^[2]

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1. Bragg Institute, Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC NSW 2232 (Australia)
2. School of Engineering and Physical Sciences, James Cook University, Townsville, Queensland 4811 (Australia)

The crystal structure of the Pmnb polymorph of Li{sub 2}MnSiO{sub 4} (prepared by solid-state synthesis in argon at 900 Degree-Sign C) is characterized by Rietveld refinement of structural models using high resolution synchrotron X-ray and neutron powder diffraction data. The crystal structure is confirmed to be isostructural with Li{sub 2}CdSiO{sub 4} with lattice parameters a=6.30694(3), b=10.75355(4), and c=5.00863(2) A, which are in good agreement with previously published data. No evidence was found for mixed lithium/manganese sites. Testing of the material as a cathode in a lithium cell shows that 1.3 lithium ions per formula unit can be extracted on the first charge cycle but very little lithium can be re-inserted. These results are compared with those of other phase-pure Li{sub 2}MnSiO{sub 4} polymorphs. - Graphical abstract: Polyhedral representation of the crystal structure of Li{sub 2}MnSiO{sub 4} in the Pmnb space group. LiO{sub 4}, MnO{sub 4} and SiO{sub 4} tetrahedra are shown in green, purple and blue, respectively. Highlights: Black-Right-Pointing-Pointer A phase-pure sample of the Pmnb polymorph of Li{sub 2}MnSiO{sub 4} was synthesized. Black-Right-Pointing-Pointer Characterized by Rietveld refinement using high resolution synchrotron X-ray and neutron powder diffraction data. Black-Right-Pointing-Pointer Results confirm the proposed Li{sub 2}CdSiO{sub 4}-type model with highly distorted Mn tetrahedra.

• OSTI ID: 22012085
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Vol. . 188; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ARGON
CATHODES
CRYSTAL STRUCTURE
CRYSTALS
ELECTRIC BATTERIES
LATTICE PARAMETERS
LITHIUM
LITHIUM IONS
MANGANESE
NEUTRON DIFFRACTION
PERMANGANATES
SILICATES
SILICON OXIDES
SOLIDS
SPACE GROUPS
SPECTROSCOPY
STRUCTURAL MODELS
SYNCHROTRONS
X RADIATION
X-RAY DIFFRACTION