US Patent 7871727 Alloy composition for lithium ion batteries

Alloy compositions, lithium ion batteries, and methods of making lithium ion batteries are described. The lithium ion batteries have anodes that contain an alloy composition that includes a) silicon, b) aluminum, c) transition metal, d) tin, e) indium, and f) a sixth element that contains yttrium, a lanthanide element, an actinide element, or a combination thereof. The alloy composition is a mixture of an amorphous phase that includes silicon and a crystalline phase that includes an intermetallic compound of 1) tin, 2) indium, and 3) the sixth element.