Structural and mechanistic features of intermetallic materials for lithium batteries

An anode: system based on intermetallic phases with a zinc-blende-type structure (InSb, GaSb and AlSb) has been studied for Lithium-ion batteries, The compound, InSb, in particular, cycles well between 1.2 and 0.5 V. After an initial "conditioning" cycle, a mechanism involving lithium insertion into an open framework structure followed by indium extrusion in the potential range 1.2-0.7 V, appears to dominate; between 0.7 and 0.5 V, a more complex mechanism occurs involving indium extrusion from a stable fee Sb anion array and subsequent lithiation of the extruded indium, In situ X-ray diffraction and extended X-ray analysis fine structure (EXAFS) data were obtained over the voltage window 1.2-0.5 V, where a rechargeable capacity of 300 mAh/g is achievable. The results indicate that after the "conditioning" reaction a LiyIn1-ySb zinc-blende framework, in which Li atoms partially substitute for In, is responsible for the good cycling behavior of the cells. Isostructural AlSb and GaSb electrodes provide inferior electrochemical capacities. (C) 2001 Elsevier Science B.V. All rights reserved.