If there is something that I've written about most in the world of clean tech, it may be batteries. They are, after all, a crucial part of a clean energy future. Not only do we need long-lasting, high-performance batteries to back up solar and wind power projects, but we also need better batteries for electric vehicles and for all of the various electronics and gadgets that are now so interwoven into our lives.
Scientists have long been experimenting with different materials to create batteries that can both store more energy and have longer lifetimes so that they don't have to be replaced as often, which makes them far more sustainable. Researchers at University of California, Irvine have made a major breakthrough with the latter by developing a battery that can be charged and discharged hundreds of thousands of times and, amazingly, it was totally by accident.
A typical lithium-ion battery starts to deteriorate after a few thousand charge cycles because lithium deposits build up on the electrodes and cause the battery to lose the ability to hold a charge. For this new battery, the researchers used nanowires, which are highly conductive and have a large surface area, making them great at holding charge as electrodes.Nanowire are very fragile though and the abuse of charge/discharge cycles breaks them down quickly. To prevent that, the researchers coated a gold nanowire in a manganese dioxide shell and encased the assembly in a Plexiglas-like gel electrolyte.
The gel coating was just an experiment, an afterthought, but when they tested it they found that the device was able to go through 200,000 cycles without any loss of capacity or any damage to the nanowire.
“That was crazy,” said Reginald Penner, chair of UCI’s chemistry department and researcher on the project, “because these things typically die in dramatic fashion after 5,000 or 6,000 or 7,000 cycles at most.”
The coated electrode was able to hold its shape better than one without a coating and the researchers think that the think the gel plasticizes the metal oxide in the battery giving it flexibility and preventing any fractures.
This new nanowire battery could one day lead to batteries that never have to be replaced, revolutionizing clean energy systems, electric vehicles, computers, even spacecraft.