Li-on batteries gradually deteriorate as they're repeatedly drained and recharged. But now researchers from University of California, Irvine have developed a new nano-wire battery that can survive hundreds of thousands of charging cycles. Over time, lithium becomes irreversibly deposited to the electrodes in li-on batteries. These build ups are called dendrites and they're what causes the batteries to degrade and ultimately fail over time, as they make it harder for charge to be effectively stored within the cell.
Scientists have wondered if nanowires could help boost the capacity of batteries for a while now, because their large surface area in a small volume could allow them to hold large quantities of charge when used as electrodes. But because they're so fine, they have proven particularly susceptible to the damage caused by dendrites of lithium.
Now, though, researchers from University of California, Irvine have created electrode nanowires using a thin core of gold, surrounded by layers of manganese dioxide and a Plexiglas-like electrolyte gel. In three months of testing, the team found that they were able to charge and discharge a simple cell made from the wires over 200,000 times without any damage or loss in capacity. For a little context, most modern li-on cells begin to give up after a few thousand cycles. Their results are published in ACS Energy Letters.
The technology is for now just a lab-based experiment. But the researchers hope that the technology could usher in a new breed of rechargeable batteries that never need to be replaced.
Image: University of California, Irvine