In a paper published in the December 16 issue of Nature Nanotechnology, Stanford researcher describes a new idea that could dramatically improve battery life in portable devices. Using silicon nanowires, battery life could jump by a factor of ten, increasing the battery life in laptops into a range of 40 to 50 hours.
In today’s batteries, the electrical storage capacity of a lithium-ion battery is limited by how much lithium can be held in the battery’s anode, which is typically made of carbon. Silicon in the battery improves the storage capacity as the material battery swells as it absorbs positively charged lithium atoms during charging and shrinks again during use. This cycle causes the silicon to "pulverize" and degrade the performance of the battery over time.
Cu said that using nanotechnology, lithium can be stored in "a forest of tiny silicon nanowires": According to the researcher, the nanowires inflate four times their normal size as they store lithium. In contrast to other silicon shapes, these nanowires do not degrade Cui said.
Cui noted that a patent application has been filed. He is considering formation of a company or an agreement with a battery manufacturer. Manufacturing the nanowire batteries would require "one or two different steps, but the process can certainly be scaled up," he said in a prepared statement. "It’s a well understood process."