Colloidal Nanocrystals of Lithiated Group 14 Elements1. (3rd November 2014)

• Record Type: Journal Article
• Authors: Cloud, Jacqueline E.; Wang, Yonglong; Yoder, Tara S.; Taylor, Lauren W.; Yang, Yongan
• Is Part Of: Angewandte Chemie. Volume 126:Number 52(2014)
• Page Start: 14755
• Page End: 14760
• Publication Date: 2014-11-03
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201408108
• Languages: English
• ISSNs: 0044-8249

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The synthesis of colloidal nanocrystals (NCs) of lithiated group 14 elements (Z=Si, Ge, and Sn) is reported, which are Li_4.4Si, Li_3.75Si, Li_4.4Ge, and Li_4.4Sn. Li_{<italic>x</italic>}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 Li_{<italic>x</italic>}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 Li_{<italic>x</italic>}Z NCs. This ball‐milling‐assisted surface protection method may be generalized to similar systems, such as Na_{<italic>x</italic>}Z and K_{<italic>x</italic>}Z. Moreover, Li_4.4Si and Li_4.4Ge NCs were conformally encapsulated in carbon fibers, providing great opportunities for studying the potential of using Li_{<italic>x</italic>}Z to mitigate the volume‐fluctuation‐induced poor cyclability problem confronted by Z anodes in lithium‐ion batteries.</p> </abstract>