"In December 2007, researchers at Stanford university reported creating a lithium ion battery with ten times the energy density (amount of energy available by weight) through using silicon nanowires deposited on stainless steel as the anode. The battery takes advantage of the fact that silicon can hold large amounts of lithium, and helps alleviate the longstanding problem of cracking by the small size of the wires. [3] To gain a tenfold improvement in energy density, the cathode would need to be improved as well; however, just improving the anode as such could provide "several" times the energy density, according to the team. The team leader, Yi Cui, expects to be able to commercialize the technology in about five years.[4]"