Reciprocal space imaging of ionic correlations in intercalation compounds

• Published in: Nature materials Vol. 19; no. 1; pp. 63 - 68
• Main Authors: Krogstad, Matthew J., Rosenkranz, Stephan, Wozniak, Justin M., Jennings, Guy, Ruff, Jacob P. C., Vaughey, John T., Osborn, Raymond
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-01-2020; Nature Publishing Group
• Subjects: 639/301/119; 639/301/299; Balances (scales); Biomaterials; Chemistry and Materials Science; Condensed Matter Physics; Correlation analysis; Crystallography; Diffraction; Electrodes; Intercalation; Intercalation compounds; Ion diffusion; Ionic mobility; Laboratories; Layered materials; Lithium; Lithium ions; Long range order; Materials Science; Metal ions; Metal oxides; Nanotechnology; Optical and Electronic Materials; Phase transitions; Point defects; Rechargeable batteries; Scattering; Short range order; Single crystals; Sodium; Synchrotron radiation; Synchrotrons; Temperature dependence; Vanadium pentoxide; X-rays
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/s41563-019-0500-7

The intercalation of alkali ions into layered materials has played an essential role in battery technology since the development of the first lithium-ion electrodes. Coulomb repulsion between the intercalants leads to ordering of the intercalant sublattice, which hinders ionic diffusion and impacts battery performance. While conventional diffraction can identify the long-range order that can occur at discrete intercalant concentrations during the charging cycle, it cannot determine short-range order at other concentrations that also disrupt ionic mobility. In this Article, we show that the use of real-space transforms of single-crystal diffuse scattering, measured with high-energy synchrotron X-rays, allows a model-independent measurement of the temperature dependence of the length scale of ionic correlations along each of the crystallographic axes in sodium-intercalated V
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. The techniques described here provide a new way of probing the evolution of structural ordering in crystalline materials.
Conventional diffraction cannot determine short-range order at concentrations that disrupt ionic mobility. Real-space transforms of single-crystal diffuse scattering now allow us to measure ionic correlation length scales in sodium-intercalated V
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.