Feeds

Get BENT: Flexy supercapacitor breaks records

Carbon nanofibre comparable with lithium batteries

Boost IT visibility and business value

It doesn't sound like a huge number, but 6.3 milliwatt-hours per cubic mm is a breakthrough: it's the highest volumetric energy density so far achieved in a microscale carbon-based supercapacitor.

Such devices are keenly sought in electronics research to drive the growing wearables market, since battery life is a big issue among glassholes and fitness-tracker owners alike. The right supercaps would be a boon, offering decent battery life and faster charging than the ubiquitous Li-ion battery.

In a paper at Nature Nanotechnology (abstract here), researchers from Nanyang Technological University (NTU) in Singapore, Tsinghua University in China, and Case Western Reserve University in the United States describe their supercapacitor as: “a hierarchically structured carbon microfibre made of an interconnected network of aligned single-walled carbon nanotubes with interposed nitrogen-doped reduced graphene oxide sheets.”

Apart from energy density, what's really excited the group is that they've created a scalable process to produce their materials. They say they've produced their carbon microfibres in 50 metre lengths, and see no serious limit to scalability.

The challenge for supercapacitors is that you need to offer a large surface area for carrying charges. A conventional capacitor is a simple creature indeed: charge-carrying foil plates, separated by a dielectric. That kind of cap' can deliver high current, but only for a short time – to store more charge, a supercapacitor has to squeeze a much higher surface area in a similar volume, while still keeping the positive and negative plates separated.

The group, led by NTU professor Yuan Chen, created a setup in which a solution containing single-wall nanotubes, graphene oxide, and ethylenediamine is pumped through a capillary column and heated in an oven for six hours.

The process causes sheets of graphene and carbon nanotubes to self-assemble into a network that runs along the length of the fibre. The resulting material, essentially a long fibrous capacitor, presents 396m2 of surface area per gram of fibre, giving the material its high capacity.

It can also be woven, which opens up applications like “smart clothing” or, more prosaically, to power medical devices, and the group claims good performance over 10,000 charge cycles.

The group says the 6.3 milliwatt-hour per cubic mm result is comparable to a 4V, 500 micro-amp-hour lithium thin film battery. ®

Boost IT visibility and business value

More from The Register

next story
Just TWO climate committee MPs contradict IPCC: The two with SCIENCE degrees
'Greenhouse effect is real, but as for the rest of it ...'
BEST BATTERY EVER: All lithium, all the time, plus a dash of carbon nano-stuff
We have found the Holy Grail (of batteries) - boffins
Asteroid's DINO KILLING SPREE just bad luck – boffins
Sauricide WASN'T inevitable, reckon scientists
Flamewars in SPAAACE: cooler fires hint at energy efficiency
Experiment aboard ISS shows we should all chill out for cleaner engines
The Sun took a day off last week and made NO sunspots
Someone needs to get that lazy star cooking again before things get cold around here
Boffins discuss AI space program at hush-hush IARPA confab
IBM, MIT, plenty of others invited to fill Uncle Sam's spy toolchest, but where's Google?
Famous 'Dish' radio telescope to be emptied in budget crisis: CSIRO
Radio astronomy suffering to protect Square Kilometre Array
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
The Essential Guide to IT Transformation
ServiceNow discusses three IT transformations that can help CIO's automate IT services to transform IT and the enterprise.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.