Colloidal nanocrystals of lithiated group 14 elements.

Autor: Cloud JE; Department of Chemistry and Geochemistry, Colorado School of Mines, 1012 14th Street, Golden, CO 80401 (USA) http://inside.mines.edu/∼yonyang/Home.html., Wang Y, Yoder TS, Taylor LW, Yang Y
Jazyk: angličtina
Zdroj: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2014 Dec 22; Vol. 53 (52), pp. 14527-32. Date of Electronic Publication: 2014 Nov 03.
DOI: 10.1002/anie.201408108
Abstrakt: The synthesis of colloidal nanocrystals (NCs) of lithiated group 14 elements (Z=Si, Ge, and Sn) is reported, which are Li4.4 Si, Li3.75 Si, Li4.4 Ge, and Li4.4 Sn. Lix Z compounds are highly reactive and cannot be synthesized by existing methods. The success relied on separating the surface protection from the crystal formation and using a unique passivating ligand. Bare Lix Z crystals were first produced by milling elemental Li and Z in an argon-filled jar. Then, under the assistance of additional milling, hexyllithium was added to passivate the freshly generated Lix Z NCs. This ball-milling-assisted surface protection method may be generalized to similar systems, such as Nax Z and Kx Z. Moreover, Li4.4 Si and Li4.4 Ge NCs were conformally encapsulated in carbon fibers, providing great opportunities for studying the potential of using Lix Z to mitigate the volume-fluctuation-induced poor cyclability problem confronted by Z anodes in lithium-ion batteries.
(© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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