Nav: Home

New materials for high-voltage supercapacitors

February 07, 2019

A research team led by Tohoku University in Japan has developed new materials for supercapacitors with higher voltage and better stability than other materials. Their research was recently published in the journal Energy and Environmental Science.

Supercapacitors are rechargeable energy storage devices with a broad range of applications, from machinery to smart meters. They offer many advantages over batteries, including faster charging and longer lifespans, but they are not so good at storing lots of energy.

Scientists have long been looking for high-performance materials for supercapacitors that can meet the requirements for energy-intensive applications such as cars. "It is very challenging to find materials which can both operate at high-voltage and remain stable under harsh conditions," says Hirotomo Nishihara, materials scientist at Tohoku University and co-author of the paper.

Nishihara and his colleagues collaborated with the supercapacitor production company TOC Capacitor Co. to develop a new material that exhibits extraordinarily high stability under conditions of high voltage and high temperature.

Conventionally, activated carbons are used for the electrodes in capacitors, but these are limited by low voltage in single cells, the building blocks that make up capacitors. This means that a large number of cells must be stacked together to achieve the required voltage. Crucially, the new material has higher single-cell voltage, reducing the stacking number and allowing devices to be more compact.

The new material is a sheet made from a continuous three-dimensional framework of graphene mesosponge, a carbon-based material containing nanoscale pores. A key feature of the materials is that it is seamless - it contains a very small amount of carbon edges, the sites where corrosion reactions originate, and this makes it extremely stable.

The researchers investigated the physical properties of their new material using electron microscopy and a range of physical tests, including X-ray diffraction and vibrational spectroscopy techniques. They also tested commercial graphene-based materials, including single-walled carbon nanotubes, reduced graphene oxides, and 3D graphene, using activated carbons as a benchmark for comparison.

They showed that the material had excellent stability at high temperatures of 60 °C and high voltage of 3.5 volts in a conventional organic electrolyte. Significantly, it showed ultra-high stability at 25°C and 4.4 volts - 2.7 times higher than conventional activated carbons and other graphene-based materials. "This is a world record for voltage stability of carbon materials in a symmetric supercapacitor," says Nishihara.

The new material paves the way for development of highly durable, high-voltage supercapacitors that could be used for many applications, including motor vehicles.
-end-


Tohoku University

Related Graphene Articles:

Graphene Flagship publishes handbook of graphene manufacturing
The EU-funded research project Graphene Flagship has published a comprehensive guide explaining how to produce and process graphene and related materials (GRMs).
How to induce magnetism in graphene
Graphene, a two-dimensional structure made of carbon, is a material with excellent mechani-cal, electronic and optical properties.
Graphene: The more you bend it, the softer it gets
New research by engineers at the University of Illinois combines atomic-scale experimentation with computer modeling to determine how much energy it takes to bend multilayer graphene -- a question that has eluded scientists since graphene was first isolated.
How do you know it's perfect graphene?
Scientists at the US Department of Energy's Ames Laboratory have discovered an indicator that reliably demonstrates a sample's high quality, and it was one that was hiding in plain sight for decades.
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.
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.
Graphene's magic is in the defects
A team of researchers at the New York University Tandon School of Engineering and NYU Center for Neural Science has solved a longstanding puzzle of how to build ultra-sensitive, ultra-small electrochemical sensors with homogenous and predictable properties by discovering how to engineer graphene structure on an atomic level.
Graphene on the way to superconductivity
Scientists at HZB have found evidence that double layers of graphene have a property that may let them conduct current completely without resistance.
More Graphene News and Graphene Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Teaching For Better Humans 2.0
More than test scores or good grades–what do kids need for the future? This hour, TED speakers explore how to help children grow into better humans, both during and after this time of crisis. Guests include educators Richard Culatta and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Dispatch 3: Shared Immunity
More than a million people have caught Covid-19, and tens of thousands have died. But thousands more have survived and recovered. A week or so ago (aka, what feels like ten years in corona time) producer Molly Webster learned that many of those survivors possess a kind of superpower: antibodies trained to fight the virus. Not only that, they might be able to pass this power on to the people who are sick with corona, and still in the fight. Today we have the story of an experimental treatment that's popping up all over the country: convalescent plasma transfusion, a century-old procedure that some say may become one of our best weapons against this devastating, new disease.   If you have recovered from Covid-19 and want to donate plasma, national and local donation registries are gearing up to collect blood.  To sign up with the American Red Cross, a national organization that works in local communities, head here.  To find out more about the The National COVID-19 Convalescent Plasma Project, which we spoke about in our episode, including information on clinical trials or plasma donation projects in your community, go here.  And if you are in the greater New York City area, and want to donate convalescent plasma, head over to the New York Blood Center to sign up. Or, register with specific NYC hospitals here.   If you are sick with Covid-19, and are interested in participating in a clinical trial, or are looking for a plasma donor match, check in with your local hospital, university, or blood center for more; you can also find more information on trials at The National COVID-19 Convalescent Plasma Project. And lastly, Tatiana Prowell's tweet that tipped us off is here. This episode was reported by Molly Webster and produced by Pat Walters. Special thanks to Drs. Evan Bloch and Tim Byun, as well as the Albert Einstein College of Medicine.  Support Radiolab today at Radiolab.org/donate.