A Stanford team of researchers have succeeded making a battery electrode that would be a perfect fit for storing large amounts of electricity in large amounts of space using tiny amounts of money. Although they only have a few grams of the new material, their expectations are far greater.
In lab tests, the electrode co-developed by Yi Cui, Colin Wessells and others could survive to 40,000 charge/discharge cycles without compromising its functionality below 80 percent. Unlike lithium ion batteries, that can only withstand some 400 cycles, this one is a real breakthrough.
“At a rate of several cycles per day, this electrode would have a good 30 years of useful life on the electrical grid,” said Colin Wessells, a graduate student in materials science and engineering who is the lead author of a paper describing the research, published this week in Nature Communications.
They did that by using the atomic structure of the crystalline hexacyanoferrate, which has an open framework that allows ions to walk through without damaging the electrode material. This is one task that lithium ion batteries don’t do well.
The researchers used hydrated potassium (a water-based solution) for the ion that needs to pass through the crystalline lattice, instead of lithium, sodium or other hydrated ions. They chose this variant because the size of the potassium ions is extremely close to the size of the openings between atoms, so any other ion solution couldn’t do any better.
Although Wessells doesn’t have a working battery right now, he and his team are optimistic at the thought that they already have an idea of how to build the other electrode (the positive one) and that the final battery will be very cheap to make and use so that it will be used in storing large amounts of power for the wind and solar industry, and to stabilize the grid’s more and more often fluctuations due to high demand.