Computational and Experimental Investigation of the Transformation of V2O5 Under Pressure
| Autor: | Gerbrand Ceder, Ulises Amador, J.M. Gallardo-Amores, N. Biskup, K. Persson, E. Morán,†,‡ and, M. E. Arroyo y de Dompablo |
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| Rok vydání: | 2007 |
| Předmět: | |
| Zdroj: | Chemistry of Materials. 19:5262-5271 |
| ISSN: | 1520-5002 0897-4756 |
| DOI: | 10.1021/cm071360p |
| Popis: | It has previously been reported that under high-pressure V2O5 (α-V2O5) transforms into a layered polymorph, β-V2O5, consisting of V5+O6 octahedra instead of V5+O5-square pyramids. Both polymorphs have a good performance as positive electrode for lithium batteries. In this work, we investigate the pressure-induced α → β transformation combining first principles and experimental methods. Density functional theory (DFT) predicts that α-V2O5 transforms to β-V2O5 at 3.3 GPa with a 11% volume contraction; experiments corroborate that at a pressure of 4 GPa, V2O5 (d = 3.36 g/cm3) transformed into a well-crystallized β-V2O5, with a much denser structure (d = 3.76 g/cm3). β-V2O5 can be also prepared at 3 GPa, although with a substantial degree of amorphization. The calculated bulk modulus of α-V2O5 (18 GPa) indicates that this is a very compressible structure; this being linked to the contraction along its b-axis (interlayer space) and to a significant decrease of a long V−O distance (V−O ≈ 2.9 A). As a result, th... |
| Databáze: | OpenAIRE |
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