A nanowire battery is a lithium-ion battery invented by a team led by Dr. Yi Cui at Stanford University in 2007. The team's invention consists of a stainless steel anode covered in silicon nanowires, to replace the traditional graphite anode. Silicon, which stores ten times more lithium than graphite, allows a far greater energy density on the anode, thus reducing the mass of the battery. The large surface area further allows for fast charging and discharging.

Traditional silicon anodes were researched and dismissed due to the tendency of silicon to crack and become unusable because it swelled with lithium during operation. The nano-wires do not suffer from this flaw. According to Dr. Cui, the battery reached 10x density on the first charge and plateaued to 8x density on subsequent charges. In order to take advantage of this anode advancement, an equivalent cathode advancement is required to achieve the increased storage density.

Commercialization is expected to occur in 2012 with the batteries costing the same or less per watt hour than conventional lithium-ion batteries. The next milestone, life cycle testing, should be completed and the team expects to achieve at least one thousand charge cycles from nano-wire batteries.