Yarns of niobium nanowire can make supercapacitors to provide a surge of energy when it’s needed
Wearable electronic devices for health and fitness monitoring are a rapidly growing area of consumer electronics; one of their biggest limitations is the capacity of their tiny batteries to deliver enough power to transmit data. Now, researchers at MIT and in Canada have found a promising new approach to delivering the short but intense bursts of power needed by such small devices.
The key is a new approach to making supercapacitors — devices that can store and release electrical power in such bursts, which are needed for brief transmissions of data from wearable devices such as heart-rate monitors, computers, or smartphones, the researchers say. They may also be useful for other applications where high power is needed in small volumes, such as autonomous microrobots.
The new approach uses yarns, made from nanowires of the element niobium, as the electrodes in tiny supercapacitors (which are essentially pairs of electrically conducting fibers with an insulator between). The concept is described in a paper in the journal ACS Applied Materials and Interfaces by MIT professor of mechanical engineering Ian W. Hunter, doctoral student Seyed M. Mirvakili, and three others at the University of British Columbia.
Nanotechnology researchers have been working to increase the performance of supercapacitors for the past decade. Among nanomaterials, carbon-based nanoparticles — such as carbon nanotubes and graphene — have shown promising results, but they suffer from relatively low electrical conductivity, Mirvakili says.
In this new work, he and his colleagues have shown that desirable characteristics for such devices, such as high power density, are not unique to carbon-based nanoparticles, and that niobium nanowire yarn is a promising an alternative.
“Imagine you’ve got some kind of wearable health-monitoring system,” Hunter says, “and it needs to broadcast data, for example using Wi-Fi, over a long distance.” At the moment, the coin-sized batteries used in many small electronic devices have very limited ability to deliver a lot of power at once, which is what such data transmissions need.
“Long-distance Wi-Fi requires a fair amount of power,” says Hunter, the George N. Hatsopoulos Professor in Thermodynamics in MIT’s Department of Mechanical Engineering, “but it may not be needed for very long.” Small batteries are generally poorly suited for such power needs, he adds.
“We know it’s a problem experienced by a number of companies in the health-monitoring or exercise-monitoring space. So an alternative is to go to a combination of a battery and a capacitor,” Hunter says: the battery for long-term, low-power functions, and the capacitor for short bursts of high power. Such a combination should be able to either increase the range of the device, or — perhaps more important in the marketplace — to significantly reduce size requirements.
The new nanowire-based supercapacitor exceeds the performance of existing batteries, while occupying a very small volume. “If you’ve got an Apple Watch and I shave 30 percent off the mass, you may not even notice,” Hunter says. “But if you reduce the volume by 30 percent, that would be a big deal,” he says: Consumers are very sensitive to the size of wearable devices.
The innovation is especially significant for small devices, Hunter says, because other energy-storage technologies — such as fuel cells, batteries, and flywheels — tend to be less efficient, or simply too complex to be practical when reduced to very small sizes. “We are in a sweet spot,” he says, with a technology that can deliver big bursts of power from a very small device.
Ideally, Hunter says, it would be desirable to have a high volumetric power density (the amount of power stored in a given volume) and high volumetric energy density (the amount of energy in a given volume). “Nobody’s figured out how to do that,” he says. However, with the new device, “We have fairly high volumetric power density, medium energy density, and a low cost,” a combination that could be well suited for many applications.
Niobium is a fairly abundant and widely used material, Mirvakili says, so the whole system should be inexpensive and easy to produce. “The fabrication cost is cheap,” he says. Other groups have made similar supercapacitors using carbon nanotubes or other materials, but the niobium yarns are stronger and 100 times more conductive. Overall, niobium-based supercapacitors can store up to five times as much power in a given volume as carbon nanotube versions.
Niobium also has a very high melting point — nearly 2,500 degrees Celsius — so devices made from these nanowires could potentially be suitable for use in high-temperature applications.
In addition, the material is highly flexible and could be woven into fabrics, enabling wearable forms; individual niobium nanowires are just 140 nanometers in diameter — 140 billionths of a meter across, or about one-thousandth the width of a human hair.
Read more: Tiny wires could provide a big energy boost
The Latest on: Nanowire supercapacitors
[google_news title=”” keyword=”nanowire supercapacitors” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Nanowire supercapacitors
- New carbon material sets energy-storage record, likely to advance supercapacitorson November 21, 2023 at 4:00 pm
Supercapacitors, such as those powering some electric buses, can store more charge than capacitors and charge and discharge more quickly than batteries. Commercial supercapacitors have two ...
- Brain-Inspired Nanowire Network May Revolutionize AIon November 15, 2023 at 4:00 pm
A study by researchers at the California NanoSystems Institute (CNSI) at UCLA along with their collaborators at the University of Sydney show a brain-inspired nanowire network AI computing system ...
- Nanowire Energy Storage Devices: Synthesis, Characterization and Applicationson November 2, 2023 at 5:00 pm
APPLICATION OF ONE-DIMENSIONAL NANOMATERIALS IN SUPERCAPACITORS 8.1 Advantages of One-Dimensional Nanomaterials in Supercapacitors 8.2 One-Dimensional Nanomaterials for Electric Double Layer ...
- Nanowire Neural Network Learns Just Like the Human Brainon October 31, 2023 at 5:00 pm
Technology Networks’ Junior Science Editor Rhianna-lily Smith was joined by Ruomin Zhu in an exclusive interview to discuss their latest study on the development of the novel nanowire neural network.
- Nanowire 'brain' network learns and remembers 'on the fly'on October 31, 2023 at 5:00 pm
Nanowire networks are made up of tiny wires that are just billionths of a metre in diameter. The wires arrange themselves into patterns reminiscent of the children's game 'Pick Up Sticks ...
- Nanowire photonicson February 8, 2023 at 10:04 am
This has led to a host of nanowire photonic devices including photodetectors, chemical and gas sensors, waveguides, LEDs, microcavity lasers, solar cells and nonlinear optical converters.
- Worldwide Nanowire Supplierson September 10, 2017 at 11:47 am
Nanowires are ultrafine wires or linear arrays of dots, formed by self-assembly. They can be made from a wide range of materials. Semiconductor nanowires made of silicon, gallium nitride and indium ...
- Raspberry Pi UPS Using Supercapacitorson April 3, 2014 at 5:32 pm
but decided to take it a step further. He picked up a pair of 50F supercapacitors. This way his UPS would last longer than his Pi would! The caps store just enough power that when the main supply ...
via Bing News