UCI Scientists Make “Infinite” Energy Storage Breakthrough
Daniel Butler - Sun, 25 Sep 2016
University of California, Irvine researchers have created a new type of energy storage device that could potentially last more than 100,000 charges.
The new battery is still in the early development stage but this breakthrough could lead to commercial batteries with substantially increased lifespans for smartphones, computers, cars and countless other battery powered IIoT devices.
The breakthrough energy storage device is described in a recently published study, available to read at the American Chemical Society under the title, “100k Cycles and Beyond: Extraordinary Cycle Stability for Mn02 Nanowires Imparted by a Gel Electrolyte.”
The UCI research team have been embarking upon an innovative approach to lithium-ion energy storage that has been a thorn in the side of the energy storage community for decades.
Earlier research has shown that more powerful batteries can be achieved using the same material. All one has to do is fashion the material into nanowires (microscopically thin strings of material) instead of thin films.
The main obstacle is battery lifespan. Nanowire batteries necessitate incredibly long wires and as the study describes, they currently perform ineffectively in practice.
A Long Way To Go
“By design, the ultralong nanowires in these capacitors amplify the influence of degradation processes that culminate in breakage of the nanowire because for ultralong nanowires, breakage ‘disconnects’ a larger fraction of the total energy storage capacity of the electrode.”
However, the UCI team have been testing different designs of the nanowire structure to discern where improvements can be made. A previous study yielded improvements with the material manganese oxide (Mn02), achieving a streak of 4,000 charging cycles while still retaining capacity.
The battery currently being worked on by the team is still only at its capacitor stage and is a fair bit of labwork away from the kind of rechargeable battery that could store renewable energy. Yet some researchers in this study have reported up to 10,000 cycles for capacitors consisting of nanotubes of graphene and Mn304. They also discuss capacitors based on a-Mn203 thin films which have reported cycles of as much as 200,000.
In this recent study, the UCI team employed the same Mn02 nanowires to boost their capacitor from around 2,000-8,000 cycles to over 100,000 cycles. The researchers made the breakthrough by coating a gold nanowire in a manganese oxide shell and encased it in an electrolyte made of Plexiglas-like gel called PMMA.
According to senior author of the UCI paper, Reginald Penner, this breakthrough was the happy result of hard work and good fortune. “Mya was playing around, and she coated this whole thing with a very thin gel layer and started to cycle it,” said Penner. “She discovered that just by using this gel, she could cycle it hundreds of thousands of times without losing any capacity.”
“That was crazy,” he added, “because these things typically die in dramatic fashion after 5,000 or 6,000 or 7,000 cycles at most.”
The UCI team believe the gel plasticises the metal oxide in the battery and makes it more flexible, which prevents cracking.
“The coated electrode holds its shape much better, making it a more reliable option,” Thai said. “This research proves that a nanowire-based battery electrode can have a long lifetime and that we can make these kinds of batteries a reality.”
The next stages of development will likely be achieving these same results but with cheaper materials.
“Accident or not, this new study marks a significant breakthrough in improving energy storage technology,” explains Kenneth Melvin, Head of Energy at Challenge Advisory. “The issue of battery life is a massive concern for the IIoT industry, especially the battery life of mobile sensors. Without tackling the issue of battery life, IIoT involvement from companies could be an expensive and impractical area of business development.”
The study was conducted in partnership with the Nanostructures for Electrical Energy Storage Energy Frontier Research Center at the University of Maryland, with funding from the Basic Energy Sciences division of the U.S. Department of Energy.
7-8 December 2016