Professor Yi Cui and associates at Stanford’s Department of materials Science and Engineering are currently working on increasing the life of chargeable lithium batteries. They hope that by using silicon nano wires as the anode instead of Graphite the battery life will be extended. They are saying that Two day batteries could be on the market in a matter of years. They have known about Nano wires for 30 years but before now they were impractical to use. Apparently the can change volume by 400 percent when inserted and extracted with lithium. Not only do they handle extreme volume changes, they also provide good electronic contact and conduction.