Nav: Home

Rapid cellphone charging getting closer to reality

October 25, 2017

The ability to charge cellphones in seconds is one step closer after researchers at the University of Waterloo used nanotechnology to significantly improve energy-storage devices known as supercapacitors.

Their novel design roughly doubles the amount of electrical energy the rapid-charging devices can hold, helping pave the way for eventual use in everything from smartphones and laptop computers, to electric vehicles and high-powered lasers.

"We're showing record numbers for the energy-storage capacity of supercapacitors," said Michael Pope, a professor of chemical engineering who led the Waterloo research. "And the more energy-dense we can make them, the more batteries we can start displacing."

Supercapacitors are a promising, green alternative to traditional batteries--with benefits including improved safety and reliability, in addition to much faster charging--but applications have been limited so far by their relatively low storage capacity.

Existing commercial supercapacitors only store enough energy, for example, to power cellphones and laptops for about 10 per cent as long as rechargeable batteries.

To boost that capacity, Pope and his collaborators developed a method to coat atomically thin layers of a conductor called graphene with an oily liquid salt in supercapacitor electrodes.

The liquid salt serves as a spacer to separate the thin graphene sheets, preventing them from stacking like pieces of paper. That dramatically increases their exposed surface area, a key to maximizing energy-storage capacity.

At the same time, the liquid salt does double duty as the electrolyte needed to actually store electrical charge, minimizing the size and weight of the supercapacitor.

"That is the really cool part of this," Pope said. "It's a clever, elegant design."

The innovation also uses a detergent to reduce the size of the droplets of oily salt - which is combined with water in an emulsion similar to salad dressing - to just a few billionths of a metre, improving their coating action. The detergent also functions like chemical Velcro to make the droplets stick to the graphene.

Increasing the storage capacity of supercapacitors means they can be made small and light enough to replace batteries for more applications, particularly those requiring quick-charge, quick-discharge capabilities.

In the short term, Pope said better supercapacitors could displace lead-acid batteries in traditional vehicles, and be used to capture energy otherwise lost by buses and high-speed trains when they brake.

Further out, although they are unlikely to ever attain the full storage capacity of batteries, supercapacitors have the potential to conveniently and reliably power consumer electronic devices, electric vehicles and systems in remote locations like space.

"If they're marketed in the correct ways for the right applications, we'll start seeing more and more of them in our everyday lives," Pope said.
-end-
The research, which also involved Zimin She, PhD student, and Debasis Ghosh, a post-doctoral fellow, was recently published in the journal ACS Nano.

University of Waterloo

Related Graphene Articles:

Graphene is 3D as well as 2D
Graphene is actually a 3D material as well as a 2D material, according to a new study from Queen Mary University of London.
Conductivity at the edges of graphene bilayers
For nanoribbons of bilayer graphene, whose edge atoms are arranged in zigzag patterns, the bands of electron energies which are allowed and forbidden are significantly different to those found in monolayer graphene.
How to purify water with graphene
Scientists from the National University of Science and Technology 'MISIS' together with their colleagues from Derzhavin Tambov State University and Saratov Chernyshevsky State University have figured out that graphene is capable of purifying water, making it drinkable, without further chlorination.
Decoupled graphene thanks to potassium bromide
The use of potassium bromide in the production of graphene on a copper surface can lead to better results.
1 + 1 does not equal 2 for graphene-like 2D materials
Physicists from the University of Sheffield have discovered that when two atomically thin graphene-like materials are placed on top of each other their properties change, and a material with novel hybrid properties emerges, paving the way for design of new materials and nano-devices.
More Graphene News and Graphene Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...