Researchers at the Massachusetts Institute of Technology discovered that yarn made of niobium nanowires enables more efficient supercapacitors. The new approach uses the yarns as the electrodes in tiny supercapacitors. Adding a coating of a conductive polymer to the yarn further increases the capacitor’s charge capacity.
The engineers discovered 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 alternative.
Wearable health-monitoring systems broadcast data over a long distance; such data transmission requires the delivery of a large quantity of power at once.
To achieve the power needs, a combination of a battery and a capacitor can be used: the battery for long-term, low-power functions, and the capacitor for short bursts of high power.
The new nanowire-based supercapacitor exceeds the performance of existing batteries and delivers big bursts of power from a very small device.
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 the nanowires could potentially be suitable for use in high-temperature applications.
The material is highly flexible and could be woven into fabrics, enabling wearable forms; individual niobium nanowires are just 140 nanometers in diameter — one-thousandth the width of a human hair.