US Patent 7906238 Silicon-containing alloys useful as electrodes for lithium-ion batteries

An electrode composition for a lithium ion battery having the formula SixSnqMyCz where q, x, y, and z represent atomic percent values and (a) (q+x)>2y+z; (b) q≧0, (c) z≧0; and (d) M is one or more metals selected from manganese, molybdenum, niobium, tungsten, tantalum, iron, copper, titanium, vanadium, chromium, nickel, cobalt, zirconium, yttrium, or a combination thereof. The Si, Sn, M, and C elements are arranged in the form of a multi-phase microstructure comprising: (a) an amorphous phase comprising silicon; (b) a nanocrystalline phase comprising a metal silicide; and (c) a phase comprising silicon carbide phase when z>0; and (d) an amorphous phase comprising Sn when q>0.