Featured Research

from universities, journals, and other organizations

Flexible, Transparent Supercapacitors Could Pave Way To E-Paper

Date:
April 6, 2009
Source:
University of Southern California
Summary:
A prototype high-performance device uses a novel architecture of carbon nanotubes and metal nanowires set in indium oxide films to temporarily store large amounts of electrical energy for release when needed.

Anatomy of a supercapacitor: two films combining Indium Oxide (In2O2) separated by a layer of Nafion film.
Credit: Image courtesy of University of Southern California

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

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 prices competitive with these existing technologies.

The latest device is a supercapacitor, a circuit component that can temporarily store large amounts of electrical energy for release when needed. 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 μm 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."

The National Science Foundation supported the research.


Story Source:

The above story is based on materials provided by University of Southern California. Note: Materials may be edited for content and length.


Journal Reference:

  1. Chongwu Zhou et al. Flexible and Transparent Supercapacitor based on Indium Nanowire / Carbon Nanotube Heterogeneous Films. Applied Physics Letters, Vol.94, Issue 4, Page 043113, 2009

Cite This Page:

University of Southern California. "Flexible, Transparent Supercapacitors Could Pave Way To E-Paper." ScienceDaily. ScienceDaily, 6 April 2009. <www.sciencedaily.com/releases/2009/03/090331091256.htm>.
University of Southern California. (2009, April 6). Flexible, Transparent Supercapacitors Could Pave Way To E-Paper. ScienceDaily. Retrieved April 20, 2014 from www.sciencedaily.com/releases/2009/03/090331091256.htm
University of Southern California. "Flexible, Transparent Supercapacitors Could Pave Way To E-Paper." ScienceDaily. www.sciencedaily.com/releases/2009/03/090331091256.htm (accessed April 20, 2014).

Share This



More Matter & Energy News

Sunday, April 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Small Reactors Could Be Future of Nuclear Energy

Small Reactors Could Be Future of Nuclear Energy

AP (Apr. 17, 2014) After the Fukushima nuclear disaster, the industry fell under intense scrutiny. Now, small underground nuclear power plants are being considered as the possible future of the nuclear energy. (April 17) Video provided by AP
Powered by NewsLook.com
Horseless Carriage Introduced at NY Auto Show

Horseless Carriage Introduced at NY Auto Show

AP (Apr. 17, 2014) An electric car that proponents hope will replace horse-drawn carriages in New York City has also been revealed at the auto show. (Apr. 17) Video provided by AP
Powered by NewsLook.com
Honda's New ASIMO Robot, More Human-Like Than Ever

Honda's New ASIMO Robot, More Human-Like Than Ever

AFP (Apr. 17, 2014) It walks and runs, even up and down stairs. It can open a bottle and serve a drink, and politely tries to shake hands with a stranger. Meet the latest ASIMO, Honda's humanoid robot. Duration: 00:54 Video provided by AFP
Powered by NewsLook.com
German Researchers Crack Samsung's Fingerprint Scanner

German Researchers Crack Samsung's Fingerprint Scanner

Newsy (Apr. 16, 2014) German researchers have used a fake fingerprint made from glue to bypass the fingerprint security system on Samsung's new Galaxy S5 smartphone. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins