Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > New fuel cell keeps going after the hydrogen runs out: Materials scientists demonstrate first SOFC capable of battery-like storage

Three possible mechanisms (left to right) can explain the operation of the vanadium oxide / platinum fuel cell after its fuel has been spent. The illustration represents a simplified cross-section of the SOFC: the top layer is the cathode (made of porous platinum), the middle layer is the electrolyte (yttria-stabilized zirconia, YSZ), and the bottom layer is the VOx anode. During normal operation, the hydrogen fuel would be at the bottom of this diagram. (Image courtesy of Quentin Van Overmeere.)
Three possible mechanisms (left to right) can explain the operation of the vanadium oxide / platinum fuel cell after its fuel has been spent. The illustration represents a simplified cross-section of the SOFC: the top layer is the cathode (made of porous platinum), the middle layer is the electrolyte (yttria-stabilized zirconia, YSZ), and the bottom layer is the VOx anode. During normal operation, the hydrogen fuel would be at the bottom of this diagram.

(Image courtesy of Quentin Van Overmeere.)

Abstract:
Imagine a kerosene lamp that continued to shine after the fuel was spent, or an electric stove that could remain hot during a power outage.

Materials scientists at Harvard have demonstrated an equivalent feat in clean energy generation with a solid-oxide fuel cell (SOFC) that converts hydrogen into electricity but can also store electrochemical energy like a battery. This fuel cell can continue to produce power for a short time after its fuel has run out.

New fuel cell keeps going after the hydrogen runs out: Materials scientists demonstrate first SOFC capable of battery-like storage

Cambridge, MA | Posted on June 30th, 2012

"This thin-film SOFC takes advantage of recent advances in low-temperature operation to incorporate a new and more versatile material," explains principal investigator Shriram Ramanathan, Associate Professor of Materials Science at the Harvard School of Engineering and Applied Sciences (SEAS). "Vanadium oxide (VOx) at the anode behaves as a multifunctional material, allowing the fuel cell to both generate and store energy."

The finding, which appears online in the journal Nano Letters, will be most important for small-scale, portable energy applications, where a very compact and lightweight power supply is essential and the fuel supply may be interrupted.

"Unmanned aerial vehicles, for instance, would really benefit from this," says lead author Quentin Van Overmeere, a postdoctoral fellow at SEAS. "When it's impossible to refuel in the field, an extra boost of stored energy could extend the device's lifespan significantly."

Ramanathan, Van Overmeere, and their coauthor Kian Kerman (a graduate student at SEAS) typically work on thin-film SOFCs that use platinum for the electrodes (the two "poles" known as the anode and the cathode). But when a platinum-anode SOFC runs out of fuel, it can continue to generate power for only about 15 seconds before the electrochemical reaction peters out.

The new SOFC uses a bilayer of platinum and VOx for the anode, which allows the cell to continue operating without fuel for up to 14 times as long (3 minutes, 30 seconds, at a current density of 0.2 mA/cm2). This early result is only a "proof of concept," according to Ramanathan, and his team predicts that future improvements to the composition of the VOx-platinum anode will further extend the cell's lifespan.

During normal operation, the amount of power produced by the new device is comparable to that produced by a platinum-anode SOFC. Meanwhile, the special nanostructured VOx layer sets up various chemical reactions that continue after the hydrogen fuel has run out.

"There are three reactions that potentially take place within the cell due to this vanadium oxide anode," says Ramanathan. "The first is the oxidation of vanadium ions, which we verified through XPS (X-ray photoelectron spectroscopy). The second is the storage of hydrogen within the VOx crystal lattice, which is gradually released and oxidized at the anode. And the third phenomenon we might see is that the concentration of oxygen ions differs from the anode to the cathode, so we may also have oxygen anions being oxidized, as in a concentration cell."

All three of those reactions are capable of feeding electrons into a circuit, but it is currently unclear exactly what allows the new fuel cell to keep running. Ramanathan's team has so far determined experimentally and quantitatively that at least two of three possible mechanisms are simultaneously at work.

Ramanathan and his colleagues estimate that a more advanced fuel cell of this type, capable of producing power without fuel for a longer period of time, will be available for applications testing (e.g., in micro-air vehicles) within 2 years.

This work was supported by the U.S. National Science Foundation (NSF), a postdoctoral scholarship from Le Fonds de la Recherche Scientifique-FNRS, and the U.S. Department of Defense's National Defense Science and Engineering Graduate Fellowship Program. The researchers also benefited from the resources of the Harvard University Center for Nanoscale Systems (a member of the NSF-funded National Nanotechnology Infrastructure Network) and the NSF-funded MRSEC Shared Experimental Facilities at MIT.

####

Contacts:
Caroline Perry
(617) 496-1351

Copyright © Harvard's School of Engineering and Applied Sciences (SEAS)

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

Nano Ruffles in Brain Matter: Freiburg researchers decipher the role of nanostructures around brain cells in central nervous system function October 31st, 2014

Gold nanoparticle chains confine light to the nanoscale October 31st, 2014

'Nanomotor lithography' answers call for affordable, simpler device manufacturing October 31st, 2014

Device invented at Johns Hopkins provides up-close look at cancer on the move: Microscopic view of metastasis could give insight about how to keep cancer in check October 31st, 2014

Thin films

New Compact SIMS at 61st AVS | Visit us on Booth 311 October 28th, 2014

Advancing thin film research with nanostructured AZO: Innovnano’s unique and cost-effective AZO sputtering targets for the production of transparent conducting oxides October 23rd, 2014

Strengthening thin-film bonds with ultrafast data collection October 23rd, 2014

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

Govt.-Legislation/Regulation/Funding/Policy

Gold nanoparticle chains confine light to the nanoscale October 31st, 2014

'Nanomotor lithography' answers call for affordable, simpler device manufacturing October 31st, 2014

Device invented at Johns Hopkins provides up-close look at cancer on the move: Microscopic view of metastasis could give insight about how to keep cancer in check October 31st, 2014

'Electronic skin' could improve early breast cancer detection October 29th, 2014

Discoveries

Nano Ruffles in Brain Matter: Freiburg researchers decipher the role of nanostructures around brain cells in central nervous system function October 31st, 2014

Gold nanoparticle chains confine light to the nanoscale October 31st, 2014

'Nanomotor lithography' answers call for affordable, simpler device manufacturing October 31st, 2014

Device invented at Johns Hopkins provides up-close look at cancer on the move: Microscopic view of metastasis could give insight about how to keep cancer in check October 31st, 2014

Announcements

Nano Ruffles in Brain Matter: Freiburg researchers decipher the role of nanostructures around brain cells in central nervous system function October 31st, 2014

Gold nanoparticle chains confine light to the nanoscale October 31st, 2014

'Nanomotor lithography' answers call for affordable, simpler device manufacturing October 31st, 2014

Device invented at Johns Hopkins provides up-close look at cancer on the move: Microscopic view of metastasis could give insight about how to keep cancer in check October 31st, 2014

Military

'Nanomotor lithography' answers call for affordable, simpler device manufacturing October 31st, 2014

Microrockets fueled by water neutralize chemical and biological warfare agents October 29th, 2014

Breakthrough in molecular electronics paves the way for DNA-based computer circuits in the future: DNA-based programmable circuits could be more sophisticated, cheaper and simpler to make October 27th, 2014

NanoTechnology for Defense (NT4D) October 22nd, 2014

Energy

Gold nanoparticle chains confine light to the nanoscale October 31st, 2014

Iranians Present Model to Predict Photocatalytic Process in Removal of Pollutants October 30th, 2014

New solar power material converts 90 percent of captured light into heat: SunShot Project aims to make solar cost competitive October 29th, 2014

New Compact SIMS at 61st AVS | Visit us on Booth 311 October 28th, 2014

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

Super stable garnet ceramics may be ideal for high-energy lithium batteries October 21st, 2014

Graphenea opens US branch October 16th, 2014

NTU develops ultra-fast charging batteries that last 20 years October 14th, 2014

Electrically conductive plastics promising for batteries, solar cells October 10th, 2014

Fuel Cells

National Synchrotron Light Source II Achieves 'First Light' October 23rd, 2014

Unique catalysts for hydrogen fuel cells synthesized in ordinary kitchen microwave oven October 14th, 2014

Researchers Pump Up Oil Accumulation in Plant Leaves: Method could greatly boost energy content of crops grown for fuel October 8th, 2014

Platinum meets its match in quantum dots from coal: Rice University's cheap hybrid outperforms rare metal as fuel-cell catalyst October 1st, 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