The tiny rechargeable, lithium-based battery was formed inside a transmission electron microscope at the Center for Integrated Nanotechnologies, a Department of Energy research facility.

Researchers say, because nanowire-based materials in lithium ion batteries offer the potential for big improvements in power and energy consumption, investigations into their operating properties should improve new generations of plug-in hybrid electric vehicles, laptops and cell phones.

An unexpected discovery was that the nanowire rod nearly doubles in length during charging - far more than its diameter increases - disputing a common belief of workers in the field.