Preparation of Li4.4GexSi1-x alloys by mechanical milling process and their properties as anode materials in all-solid-state lithium batteries

Li4.4GexSi1-x alloys were prepared by use of a high-energy ball-milling process. The Li4.4GexSi1-x alloys formed a solid solution over the whole composition range of 0less than or equal toxless than or equal to1. Those alloys were isomorphic with an Li15Ge4 crystalline phase that had a D8(6) structure belonging to a space group I43d. The lattice constants of the alloys were increased with an increase in the compositional parameter x. The Li4.4GexSi1-x alloys were investigated as negative electrode materials for all-solid-state lithium batteries with an inorganic solid electrolyte a-60Li(2)S (.) 40SiS(2) (mol%). Among the obtained alloys, the Li4.4Ge0.67Si0.33 alloy showed the largest specific capacity of 190 mA h g(-1) and good charge-discharge reversibility. (C) 2004 Elsevier B.V. All rights reserved.