Patent ID: 7851085

Claim:
A lithium ion battery comprising a cathode, an anode, and an electrolyte in electrical communication with 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; and e) a fifth 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; and wherein the alloy composition is a mixture of an amorphous phase comprising silicon and a nanocrystalline phase comprising an intermetallic compound of tin and the fifth element.