According to a paper which was published in the Nature Nanotechnology journal, the researchers have proudly reported on accomplishing something that battery designers have been attempting to achieve for several decades - to design an authentically pure lithium anode.
Currently, mobile devices have lithium ion batteries that are limited in features simply because of the word "ion" in the battery's name. Using this type of battery would mean being able to safely use lithium solely in the battery's cell where there are ions. This results to a lot of wasted potential energy.
All batteries are made up of three important parts. These are the electrolyte that provides the electrons, an anode for electron discharging, and a cathode for receiving the discharged electrons.
While most of the batteries that we know today claim to be lithium, they are in reality, partly true. In fact, they are lithium ion batteries. This is because the lithium is only found in the electrolyte and not in the anode. When pure lithium is present in an anode, it will definitely enhance the battery's full efficiency.
During the battery's charging mode, the lithium ions in the electrolyte, which are positively charged, become attracted to the anode which is negatively charged. This results to the lithium accumulating on the anode. At present, a lithium ion battery has an anode that is made of silicon or graphite.
The desire to use lithium for the anode had always been attempted by engineers but seemed to be an elusive feat. The reason is that lithium ions, during charging, expand while they gather on the anode.
Professor Yi Cui of Material Science and Engineering and head of the research team says, "Of all the materials that one might use in an anode, lithium has the greatest potential. Some call it the Holy Grail." He further adds that apart from being lightweight, lithium "has the highest energy density. You get more power per volume and weight, leading to lighter, smaller batteries with more power."
All types of anode material, which include graphite and silicon, expand during charging. However, lithium's expansion behavior during the same charging period is described as "virtually infinite" compared to other materials. Moreover, it is also described as uneven resulting to pits and cracks in the external surface.
The research team from Stanford has developed a strengthening technique on the silicon anodes by creating them using nano wires and hollow nano particles. At the same time, the anode is also coated with silicon oxide on the outer layer which is a type of ceramic material that makes the silicon unable to expand.
At this point, the batteries are capable of operating for over 6,000 cycles. Compared to the cycle life standards of the currently available lithium-ion battery, the new batteries seemed very promising indeed.
