Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Flexible supercapacitor raises bar for volumetric energy density: Could be woven into clothes to power wearable medical, communications devices

Abstract:
Scientists have taken a large step toward making a fiber-like energy storage device that can be woven into clothing and power wearable medical monitors, communications equipment or other small electronics.

Flexible supercapacitor raises bar for volumetric energy density: Could be woven into clothes to power wearable medical, communications devices

Cleveland, OH | Posted on May 12th, 2014

The device is a supercapacitor—a cousin to the battery. This one packs an interconnected network of graphene and carbon nanotubes so tightly that it stores energy comparable to some thin-film lithium batteries—an area where batteries have traditionally held a large advantage.

The product's developers, engineers and scientists at Nanyang Technological University (NTU) in Singapore, Tsinghua University in China, and Case Western Reserve University in the United States, believe the storage capacity by volume (called volumetric energy density) is the highest reported for carbon-based microscale supercapacitors to date: 6.3 microwatt hours per cubic millimeter.

The device also maintains the advantage of charging and releasing energy much faster than a battery. The fiber-structured hybrid materials offer huge accessible surface areas and are highly conductive.

The researchers have developed a way to continuously produce the flexible fiber, enabling them to scale up production for a variety of uses. To date, they've made 50-meter long fibers, and see no limits on length.

They envision the fiber supercapacitor could be woven into clothing to power medical devices for people at home, or communications devices for soldiers in the field. Or, they say, the fiber could be a space-saving power source and serve as "energy-carrying wires" in medical implants.

Yuan Chen, a professor of chemical engineering at NTU led the new study, working with Dingshan Yu, Kunli Goh, Hong Wang, Li Wei and Wenchao Jiang at NTU; Qiang Zhang at Tsinghua; and Liming Dai at Case Western Reserve. The scientists report their research in Nature Nanotechnology: http://dx.doi.org/10.1038/nnano.2014.93.

Dai, a professor of macromolecular science and engineering at Case Western Reserve and a co-author of the paper, explained that most supercapacitors have high power density but low energy density, which means they can charge quickly and give a boost of power, but don't last long. Conversely, batteries have high energy density and low power density, which means they can last a long time, but don't deliver a large amount of energy quickly.

Microelectronics to electric vehicles can benefit from energy storage devices that offer high power and high energy density. That's why researchers are working to develop a device that offers both.

To continue to miniaturize electronics, industry needs tiny energy storage devices with large volumetric energy densities.

By mass, supercapacitors might have comparable energy storage, or energy density, to batteries. But because they require large amounts of accessible surface area to store energy, they have always lagged badly in energy density by volume.

Their approach

To improve the energy density by volume, the researchers designed a hybrid fiber.

A solution containing acid-oxidized single-wall nanotubes, graphene oxide and ethylenediamine, which promotes synthesis and dopes graphene with nitrogen, is pumped through a flexible narrow reinforced tube called a capillary column and heated in an oven for six hours.

Sheets of graphene, one to a few atoms thick, and aligned, single-walled carbon nanotubes self-assemble into an interconnected prorous network that run the length of the fiber.

The arrangement provides huge amounts of accessible surface area—396 square meters per gram of hybrid fiber—for the transport and storage of charges.

But the materials are tightly packed in the capillary column and remain so as they're pumped out, resulting in the high volumetric energy density.

The process using multiple capillary columns will enable the engineers to make fibers continuously and maintain consistent quality, Chen said.

The findings

The researchers have made fibers as long as 50 meters and found they remain flexible with high capacity of 300 Farad per cubic centimeter.

In testing, they found that three pairs of fibers arranged in series tripled the voltage while keeping the charging/discharging time the same.

Three pairs of fibers in parallel tripled the output current and tripled the charging/discharging time, compared to a single fiber operated at the same current density.

When they integrate multiple pairs of fibers between two electrodes, the ability to store electricity, called capacitance, increased linearly according to the number of fibers used.

Using a polyvinyl alcohol /phosphoric acid gel as an electrolyte, a solid-state micro-supercapacitor made from a pair of fibers offered a volumetric density of 6.3 microwatt hours per cubic millimeter, which is comparable to that of a 4-volt-500-microampere-hour thin film lithium battery.

The fiber supercapacitor demonstrated ultrahigh energy-density value, while maintaining the high power density and cycle stability.

"We have tested the fiber device for 10,000 charge/discharge cycles, and the device retains about 93 percent of its original performance," Yu said, " while conventional rechargeable batteries have a lifetime of less than 1000 cycles."

The team also tested the device for flexible energy storage. The device was subjected to constant mechanical stress and its performance was evaluated. "The fiber supercapacitor continues to work without performance loss, even after bending hundreds of times," Yu said.

"Because they remain flexible and structurally consistent over their length, the fibers can also be woven into a crossing pattern into clothing for wearable devices in smart textiles." Chen said.

Such clothing could power biomedical monitoring devices a patient wears at home, providing information to a doctor at a hospital, Dai said. Woven into uniforms, the battery-like supercapacitors could power displays or transistors used for communication.

The researchers are now expanding their efforts. They plan to scale up the technology for low-cost, mass production of the fibers aimed at commercializing high-performance micro-supercapacitors.

In addition, "The team is also interested in testing these fibers for multifunctional applications, including batteries, solar cells, biofuel cells, and sensors for flexible and wearable optoelectronic systems," Dai said. "Thus, we have opened up many possibilities and still have a lot to do."

###

The Ministry of Education, Singapore and Asian Office of Aerospace Research and Development of the U.S. Air Force and the U.S, Air Force Office of Scientific Research funded the research.

####

For more information, please click here

Contacts:
Kevin Mayhood

216-368-4442

Copyright © Case Western Reserve University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Seeing quantum motion August 30th, 2015

Artificial leaf harnesses sunlight for efficient fuel production August 30th, 2015

Researchers use DNA 'clews' to shuttle CRISPR-Cas9 gene-editing tool into cells August 30th, 2015

Draw out of the predicted interatomic force August 30th, 2015

Graphene

Successful boron-doping of graphene nanoribbon August 27th, 2015

Developing Component Scale Composites Using Nanocarbons August 26th, 2015

Quantum diffraction at a breath of nothing: Physicists build stable diffraction structure in atomically thin graphene August 25th, 2015

Graphene oxide's secret properties revealed at atomic level: A research team found that graphene oxide's inherent defects give rise to a surprising mechanical property August 24th, 2015

Thin films

Electrospray solves longstanding problem in Langmuir-Blodgett assembly: The electrospray spreads water-soluble solvents on water while minimizing mixing August 20th, 2015

Scientists achieve major breakthrough in thin-film magnetism August 17th, 2015

Rice, Penn State open center for 2-D coatings: National Science Foundation selects universities to develop atom-thin materials with industry partners August 13th, 2015

Thin films offer promise for ferroelectric devices: Researchers at Tokyo Institute of Technology demystify the ferroelectric properties observed in hafnium-oxide-based thin films, revealing a potentially useful device material August 3rd, 2015

Govt.-Legislation/Regulation/Funding/Policy

Seeing quantum motion August 30th, 2015

Artificial leaf harnesses sunlight for efficient fuel production August 30th, 2015

Researchers use DNA 'clews' to shuttle CRISPR-Cas9 gene-editing tool into cells August 30th, 2015

Draw out of the predicted interatomic force August 30th, 2015

Nanotubes/Buckyballs/Fullerenes

Developing Component Scale Composites Using Nanocarbons August 26th, 2015

Southampton scientists find new way to detect ortho-para conversion in water August 25th, 2015

Revolutionary MIT-Developed Nanotechnology Company Showcases at CAMX in Dallas August 20th, 2015

Engineering a better 'Do: Purdue researchers are learning how August 4th, 2015

Nanomedicine

Researchers use DNA 'clews' to shuttle CRISPR-Cas9 gene-editing tool into cells August 30th, 2015

Iranian Scientists Use Artemisia Annua Plant to Produce Breast Cancer Drugs August 29th, 2015

Small but heading for the big time: Nanobiotix half year results for the six months ended 30 June 2015, in line with expectations: Major clinical achievements and corporate developments August 28th, 2015

A new technique to make drugs more soluble August 28th, 2015

Sensors

Successful boron-doping of graphene nanoribbon August 27th, 2015

Nanotechnology that will impact the Security & Defense sectors to be discussed at NanoSD2015 conference August 25th, 2015

High Precision, High Stability XYZ Microscope Stages, with Capacitive Feedback August 18th, 2015

Setting ground rules for nanotechnology research: Two new projects set the stage for nanotechnology research to move into Big Data August 18th, 2015

Discoveries

Seeing quantum motion August 30th, 2015

Artificial leaf harnesses sunlight for efficient fuel production August 30th, 2015

Researchers use DNA 'clews' to shuttle CRISPR-Cas9 gene-editing tool into cells August 30th, 2015

Draw out of the predicted interatomic force August 30th, 2015

Announcements

Seeing quantum motion August 30th, 2015

Artificial leaf harnesses sunlight for efficient fuel production August 30th, 2015

Researchers use DNA 'clews' to shuttle CRISPR-Cas9 gene-editing tool into cells August 30th, 2015

Draw out of the predicted interatomic force August 30th, 2015

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Seeing quantum motion August 30th, 2015

Researchers use DNA 'clews' to shuttle CRISPR-Cas9 gene-editing tool into cells August 30th, 2015

Draw out of the predicted interatomic force August 30th, 2015

Iranian Scientists Use Artemisia Annua Plant to Produce Breast Cancer Drugs August 29th, 2015

Military

Seeing quantum motion August 30th, 2015

These microscopic fish are 3-D-printed to do more than swim: Researchers demonstrate a novel method to build microscopic robots with complex shapes and functionalities August 26th, 2015

Nanotechnology that will impact the Security & Defense sectors to be discussed at NanoSD2015 conference August 25th, 2015

Industrial Nanotech, Inc. Provides Update On Hospital Project, PCAOB Audit, and New Heat Shield™ Line August 24th, 2015

Textiles/Clothing

Nanotechnology that will impact the Security & Defense sectors to be discussed at NanoSD2015 conference August 25th, 2015

Possibility to Produce Nanofibers with Controlled Size August 13th, 2015

Engineering a better 'Do: Purdue researchers are learning how August 4th, 2015

Nanoparticles Give Antibacterial Properties to Machine-Woven Carpets August 4th, 2015

Battery Technology/Capacitors/Generators/Piezoelectrics/Thermoelectrics/Energy storage

Artificial leaf harnesses sunlight for efficient fuel production August 30th, 2015

CWRU researchers efficiently charge a lithium-ion battery with solar cell: Coupling with perovskite solar cell holds potential for cleaner cars and more August 27th, 2015

'Diamonds from the sky' approach turns CO2 into valuable products August 19th, 2015

Drexel engineers 'sandwich' atomic layers to make new materials for energy storage August 15th, 2015

Research partnerships

Nanocatalysts improve processes for the petrochemical industry August 28th, 2015

Announcing Oxford Instruments and School of Physics signing a Memorandum of Understanding August 26th, 2015

Researchers combine disciplines, computational programs to determine atomic structure August 26th, 2015

Developing Component Scale Composites Using Nanocarbons August 26th, 2015

Solar/Photovoltaic

Artificial leaf harnesses sunlight for efficient fuel production August 30th, 2015

CWRU researchers efficiently charge a lithium-ion battery with solar cell: Coupling with perovskite solar cell holds potential for cleaner cars and more August 27th, 2015

Novel nanostructures for efficient long-range energy transport August 21st, 2015

Charge transport in hybrid silicon solar cells August 17th, 2015

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic