Patent ID: 7871727

Claim:
A lithium ion battery comprising a cathode, an anode, and an electrolyte in electrical communication with both the anode and the cathode, wherein the anode comprises an alloy composition comprising a) silicon in an amount of 35 to 70 mole percent; b) aluminum in an amount of 1 to 45 mole percent; c) a transition metal in an amount of 5 to 25 mole percent; d) tin in an amount of 1 to 15 mole percent; e) indium in an amount up to 15 mole percent; and f) a sixth element comprising yttrium, a lanthanide element, an actinide element, or a combination thereof in an amount of 2 to 15 mole percent, wherein each mole percent is based on a total number of moles of all elements except lithium in the alloy composition; wherein the alloy composition is a mixture of an amorphous phase comprising silicon and a nanocrystalline phase comprising an intermetallic compound with tin, indium, and the sixth element, and wherein the nanocrystalline phase comprises crystalline materials having a maximum dimension of about 5 to about 50 nanometers.