An electrode composition for a lithium ion battery that includes an amorphous alloy having the formula Si.sub.xM.sub.yAl.sub.z where x, y, and z represent atomic percent values and (a) x+y+z=100, (b) x.gtoreq.55, (c) y<22, (d) z>0, and (e) M is one or more metals selected from the group consisting of manganese, molybdenum, niobium, tungsten, tantalum, iron, copper, titanium, vanadium, chromium, nickel, cobalt, zirconium, yttrium, and combinations thereof.