Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Oxygen Ions for Fuel Cells Get Loose at Low(er) Temperatures

27.06.2008
Seeking to understand a new fuel cell material, a research team working at the National Institute of Standards and Technology (NIST), in collaboration with the University of Liverpool, has uncovered a novel structure that moves oxygen ions through the cell at substantially lower temperatures than previously thought possible.

The finding announced this month in Nature Materials may be key to solving fuel cell reliability issues and lead to reduced operating costs in high-performance stationary fuel cells.

Electricity is produced in fuel cells from the electrochemical reaction between a hydrogen-rich fuel and oxygen that produces electric current and water. Research on small fuel cells for cars has dominated the news, but stationary fuel cells are the Goliaths—operating at up to 70 percent efficiency and providing enough electricity—up to 100 megawatts—to power small cities, hospitals, military installations or airports without relying on the electric power grid. Smaller versions are being considered for auxiliary power units in such applications as refrigeration trucks to reduce engine idling.

They are called “solid oxide” fuel cells (SOFCs) because the heart of the cell is a solid electrolyte that transports oxygen ions extracted from air to meet with hydrogen atoms. This alchemy traditionally requires high temperatures—about 850 degrees Celsius in conventional SOFCs—and therefore long startup times, ranging from 45 minutes to eight hours.

The high temperatures necessitate more expensive materials and higher operating costs, so stationary fuel cell research is focused on lowering operating temperatures as well as shortening startup times. The U.S. Department of Energy’s goal is to slash the startup time to two minutes.

Chemists at the University of Liverpool fabricated a new oxygen ion electrolyte material of lanthanum, strontium, gallium and oxygen and sent it to the NIST Center for Neutron Research (NCNR) to investigate with collaborators from NIST, the University of Maryland and University College London. Neutrons provide an atomic-scale view of materials so scientists can “see” what is happening at that level.

The oxygen ions in the new materials become mobile at 600 degrees C, much lower than previously studied materials. Researchers suspected the reason lay in the location of the oxygen ions in the crystal framework of the compound. The neutron probes allowed them to determine the basic crystal structure that held the lanthanum, strontium, gallium and oxygen atoms, however the exact nature of the extra oxygen ions was unclear.

NCNR researchers recommended borrowing a method from radio astronomy called maximum entropy analysis. “When astronomers are not able to visualize a specific part of an image because it constitutes such a small part of the total information collected, they utilize a part of applied mathematics called information theory to reconstruct a sharper image,” explains NCNR researcher Mark Green. “The combination of neutron diffraction and maximum entropy analysis not only allowed us to determine the location of additional oxygen ions outside of the basic framework, but revealed a new mechanism for ion conduction.”

“It allows us to take a fundamentally different approach in the design of future materials, so that we can harness this new mechanism for oxide ion conduction and produce lower operating fuel cells,” says Green. “This type of work is very important to us, which is why as part of the NCNR expansion we are developing a new materials diffractometer that will greatly enhance our capabilities in energy related research.”

* X. Kuang, M.A. Green, H. Niu, P Zajdel, C. Dickinson, J.B. Claridge, L. Jantsky and M.J. Rosseinsky. Interstitial oxide ion conductivity in the layered tetrahedral network melilite structure. Nature Materials, June 2008

Evelyn Brown | newswise
Further information:
http://www.nist.gov

More articles from Power and Electrical Engineering:

nachricht Nano-scale process may speed arrival of cheaper hi-tech products
09.11.2018 | University of Edinburgh

nachricht Nuclear fusion: wrestling with burning questions on the control of 'burning plasmas'
25.10.2018 | Lehigh University

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Nonstop Tranport of Cargo in Nanomachines

Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.

Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Coherence Tomography: German-Japanese Research Alliance hosted Medical Imaging Conference

19.11.2018 | Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

 
Latest News

Nonstop Tranport of Cargo in Nanomachines

20.11.2018 | Life Sciences

Researchers find social cultures in chimpanzees

20.11.2018 | Life Sciences

When AI and optoelectronics meet: Researchers take control of light properties

20.11.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>