Subscribe to our free daily newsletters
  Energy News  




Subscribe to our free daily newsletters



ENERGY TECH
How does oxygen get into a fuel cell
by Staff Writers
Vienna, Austria (SPX) Mar 30, 2017


The surface is created using pulsed lasers. Image courtesy TU Wien.

Fuel cells use a simple chemical reaction, such as the combination of oxygen and hydrogen to form water, to generate electricity. The question of which is the best material to use when making ceramic fuel cells is not a straightforward one, however. New materials are required that act as a catalyst for the chemical reaction required with maximum efficiency, but that also last as long as possible without their properties changing.

Previous efforts to develop materials that fulfil these requirements have largely been based on trial and error. However, teams at TU Wien have now managed to find a way to make targeted alterations to the surface of fuel cells on an atomic scale and take measurements at the same time. As a result, it is now possible to explain important phenomena for the first time, including the reasons why strontium atoms are problematic and the fact that cobalt can be useful in a fuel cell.

The oxygen supply bottleneck
At the cathode, the positive terminal of the fuel cell, oxygen is incorporated into the fuel cell material from the air. Electrically charged oxygen ions then have to travel through the material and react with the fuel, for example hydrogen, at the negatively charged side, the anode.

"The bottleneck within this whole process is the incorporation of oxygen at the cathode," explains Ghislain Rupp, from the research group led by Professor Jurgen Fleig at TU Wien's Institute of Chemical Technologies and Analytics. The team led by Professor Andreas Limbeck and based at the same institute was also involved in this research project.

Fuel cells need to be operated at extremely high temperatures, somewhere in the region of between 700 and 1000 degrees Celsius, in order to ensure that the oxygen is incorporated quickly enough. Researchers have long been trying to identify better cathode materials that will allow for the operating temperature to be reduced. "There are some well-known options that are of particular interest, including lanthanum strontium cobaltite, or LSC for short," explains Ghislain Rupp. The major problem in this case is that these materials do not remain stable in the long term. There is always a point at which the activity drops and the performance of the fuel cell dwindles. Until now, it has only been possible to guess at the precise reason for this.

Targeted surface alterations
One thing has always been clear: the surface of the cathode, where the oxygen is to settle before entering the fuel cell, has a crucial role to play. With this in mind, the teams at TU Wien developed a method of making targeted alterations to the surface that also allows for measurements to be taken at the same time in order to determine the effects of this on the electrical properties of the fuel cell.

"We use a laser pulse to vaporise various materials, which then accumulate in tiny volumes on the surface," explains Rupp. "This enables us to modify the composition of the cathode surface in small, precise doses, whilst also monitoring how this affects the resistance of the system."

The damaging effect of excessive strontium
In this way, we have been able to show that materials containing large volumes of strontium on the surface have a damaging effect: "If there are too many strontium atoms on the surface, oxygen is not incorporated very effectively at all," says Rupp. "The oxygen is taken up by the cathode surface very unevenly. At some preferential spots, for example where cobalt atoms are located, oxygen is incorporated effectively. However, at the points where strontium dominates, hardly any oxygen is able to enter the cathode." This also explains why the fuel cells deteriorate over time, as the strontium inside the material migrates to the surface and covers any active cobalt accumulations, ultimately keeping the air away from the fuel cell.

These findings provide important information on how oxygen is fundamentally incorporated into materials such as LSC and which processes cause the performance of fuel cells to deteriorate. "This research has taken us a huge step closer to the technical use of LSC as a fuel cell material," Rupp believes. "What's more, our new method of investigation combining ultra-precise coating with electrical measurement is sure to find other important applications within the field of solid state ionics."

Research paper

ENERGY TECH
New gel-like coating beefs up the performance of lithium-sulfur batteries
New Haven CT (SPX) Mar 23, 2017
Yale scientists have developed an ultra-thin coating material that has the potential to extend the life and improve the efficiency of lithium-sulfur batteries, one of the most promising areas of energy research today. In a study published online March 20 in the Proceedings of the National Academy of Sciences, researchers describe the new material - a dendrimer-graphene oxide composite film ... read more

Related Links
Vienna University of Technology
Powering The World in the 21st Century at Energy-Daily.com


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

ENERGY TECH
World Bank urges more investment for developing global electricity

US states begin legal action on Trump energy delay

Program to be axed saves energy in LA buildings

Energy demand metrics indicate strong U.S. economy

ENERGY TECH
How does oxygen get into a fuel cell

Clarifying how lithium ions ferry around in rechargeable batteries

Building a market for renewable thermal technologies

New gel-like coating beefs up the performance of lithium-sulfur batteries

ENERGY TECH
Japan scientist eyes energy burst from 'typhoon turbine'

Mega-wind farm offshore Denmark clears hurdle

North Carolina offshore wind hailed as job creator

North Carolina ready for offshore wind energy auction

ENERGY TECH
Report: Global renewable power capacity expanding

Financialization's negative effect on the American solar industry

Bio-inspired energy storage: A new light for solar power

First Solar to deliver 48Mw Manildra solar farm

ENERGY TECH
Toshiba's US nuclear unit files for bankruptcy protection

Toshiba execs under fire as loss forecast balloons

Westinghouse's woes spotlight US nuclear sector's decline

Japan high court rules nuclear reactors can restart

ENERGY TECH
Ridding the oceans of plastics by turning the waste into valuable fuel

Shell unveils giant new high-tech research lab in India

Hydrogen production: This is how green algae assemble their enzymes

Community in chaotic Jakarta goes green to fight eviction

ENERGY TECH
Gazprom boasts of expanding gas exports

Qatar to increase gas production by 10 percent

New technology could end costly crude oil pipeline blockages

Slow start for oil prices in the first trading day in April

ENERGY TECH
US climate science hearing descends into bullying 'food-fight'

Trump keeps world dangling on Paris climate pact

Trump moves to roll back Obama climate measures

China calls on US to honour climate commitments




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement