Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Nanowires plus nanotubes equals supercapacitance

Anatomy of a supercapacitor: two films combining Indium Oxide (In2O2) separated by a layer of Nafion film.
Anatomy of a supercapacitor: two films combining Indium Oxide (In2O2) separated by a layer of Nafion film.

Abstract:
It is a completely transparent and flexible energy conversion and storage device that you can bend and twist like a poker card.

Nanowires plus nanotubes equals supercapacitance

Los Angeles, CA | Posted on March 31st, 2009

It continues a line of prototype devices created at the USC Viterbi School of Engineering that can perform the electronic operations now usually handled by silicon chips using carbon nanotubes and metal nanowires set in indium oxide films, and can potentially do so at prices competitive with those of existing technologies.

The device is a supercapacitor, a circuit component that can temporarily store large amounts of electrical energy for release when needed. A team headed by Chongwu Zhou describes it a newly-published paper on "Flexible and Transparent Supercapacitor based on Indium Nanowire / Carbon Nanotube Heterogeneous Films" in the journal Applied Physics Letters (Vol.94, Issue 4, Page 043113, 2009).

Its creators believe the device points the way to further applications, such as flexible power supply components in "e-paper" displays and conformable products.

The device stores an energy density of 1.29 Watt-hour/kilogram with a specific capacitance of 64 Farad/gram. By contrast, conventional capacitors usually have an energy density of less than 0.1 Wh/kg and a storage capacitance of several tenth millifarads.

Zhou, who holds the Jack Munushiun Early Career Chair at the USC Ming Hsieh Department of Electrical Engineering, worked with USC graduate students Po-Chiang Chen and Sawalok Sukcharoenchoke, and post-doc Guozhen Shen.

The group incorporated metal oxide nanowires with carbon nanotubes (CNTs) to form heterogeneous films and further optimized the film thickness attaching on transparent plastic substrates to maintain the mechanical flexibility and optical transparency of the supercapacitors.

According to Zhou, the work, based on combing CNTs with metal nanowiers represents an advance on earlier attempts to produce supercapacitors using just CNTs or graphite.

Such efforts resulted in only modest performance compared to those using transition metal oxide materials, including such oxides of iron, manganese and rubidium. Moreover, energy storage devices made by these materials have neither mechanical flexibility nor optical transparency, which have confined their applications in the flexible and transparent electronics.

The critical improvement in performance, according to the research, can be attributed to the incorporation of metal oxide nanowires with CNT films. Indium oxide nanowire, with the properties of wide band gap, high aspect ratio, and short diffusion path length, can be one of the best candidates for transparent electrochemical capacitors. Professor Zhou's lab has pioneered this material over the past several years.

These new devices, by contrast, "demonstrated enhanced specific capacitance, power density, energy density, and long operation cycles, compared to those supercapacitors made only by CNTs," says the new release.

"We successfully produced a prototype of flexible and transparent supercapacitors built on two important nanostructured materials (including metal oxide nanowires and CNTs).

The researchers not only created metal oxide nanowire / CNT heterogeneous films as active materials and current collecting electrodes for the supercapacitors, but also examined the stability of the transparent and flexible supercapacitors through a large cycle number of charge/discharge measurements.

The paper contains description of how the new devices are made:

"CNT films were fabricated by vacuum filtration method. An adhesive and flat poly (dimethysiloxane) (PDMS) stamp was adapted to peel the CNT film off of the filtration membrane and then released it onto a polyethylene terephtalate (PET) substrate. In2O3 nanowires with a diameter of ~20 nm and a length of ~5 ìm were synthesized by a pulsed laser deposition (PLD) method. The as-grown nanowires were sonicated into IPA solutions and then dispersed upon transferred CNT films to form In2O3 nanowire /CNT heterogeneous film for transparent and flexible supercapacitor study.

"In addition, with the increasing amount of In2O3 nanowires dispersed upon CNT films, the specific capacitance of the heterogeneous supercapacitor can be dramatically improved up from 25.4 Farad/gram to 64 Farad/gram. In comparisons to supercapacitors made by other transition metal oxide nanostructured materials, this observation indicates a good stability of In2O3 nanowire / CNT heterogeneous films for long-term capacitor applications."

####

About USC
Located in Los Angeles, a global center for arts, technology and international trade, the University of Southern California is one of the world’s leading private research universities. USC enrolls more international students than any other U.S. university and offers extensive opportunities for internships and study abroad. With a strong tradition of integrating liberal and professional education, USC fosters a vibrant culture of public service and encourages students to cross academic as well as geographic boundaries in their pursuit of knowledge.

For more information, please click here

Copyright © USC

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

Industrial Nanotech, Inc. to Publish PCAOB Audited Financials July 31st, 2014

Nanostructured metal-oxide catalyst efficiently converts CO2 to methanol: Highly reactive sites at interface of 2 nanoscale components could help overcome hurdle of using CO2 as a starting point in producing useful products July 31st, 2014

Carnegie Mellon Chemists Create Nanofibers Using Unprecedented New Method July 31st, 2014

Pressure probing potential photoelectronic manufacturing compound July 31st, 2014

Possible Futures

IBM Announces $3 Billion Research Initiative to Tackle Chip Grand Challenges for Cloud and Big Data Systems: Scientists and engineers to push limits of silicon technology to 7 nanometers and below and create post-silicon future July 10th, 2014

Virus structure inspires novel understanding of onion-like carbon nanoparticles April 10th, 2014

Local girl does good March 22nd, 2014

Surface Characteristics Influence Cellular Growth on Semiconductor Material March 12th, 2014

Nanotubes/Buckyballs

SouthWest NanoTechnologies Names NanoSperse as A SWeNT Certified Compounder July 29th, 2014

A new way to make microstructured surfaces: Method can produce strong, lightweight materials with specific surface properties July 29th, 2014

UCF Nanotech Spinout Developing Revolutionary Battery Technology: Power the Next Generation of Electronics with Carbon July 23rd, 2014

University of Houston researchers create new method to draw molecules from live cells: Technique using magnetic nanomaterials offers promise for diagnosis, gene therapy July 17th, 2014

Announcements

Industrial Nanotech, Inc. to Publish PCAOB Audited Financials July 31st, 2014

Nanostructured metal-oxide catalyst efficiently converts CO2 to methanol: Highly reactive sites at interface of 2 nanoscale components could help overcome hurdle of using CO2 as a starting point in producing useful products July 31st, 2014

Carnegie Mellon Chemists Create Nanofibers Using Unprecedented New Method July 31st, 2014

Pressure probing potential photoelectronic manufacturing compound July 31st, 2014

Energy

Nanostructured metal-oxide catalyst efficiently converts CO2 to methanol: Highly reactive sites at interface of 2 nanoscale components could help overcome hurdle of using CO2 as a starting point in producing useful products July 31st, 2014

From Narrow to Broad July 30th, 2014

Oregon chemists eye improved thin films with metal substitution: Solution-based inorganic process could drive more efficient electronics and solar devices July 21st, 2014

Steam from the sun: New spongelike structure converts solar energy into steam July 21st, 2014

Battery Technology/Capacitors/Generators/Piezoelectrics/Thermoelectrics

Tough foam from tiny sheets: Rice University lab uses atom-thick materials to make ultralight foam July 29th, 2014

Stanford team achieves 'holy grail' of battery design: A stable lithium anode - Engineers use carbon nanospheres to protect lithium from the reactive and expansive problems that have restricted its use as an anode July 27th, 2014

Nano-supercapacitors for electric cars July 25th, 2014

Compact Vibration Harvester Power Supply with Highest Efficiency Opens Door to “Fix-and-Forget” Sensor Nodes July 23rd, 2014

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







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE