Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

ORNL microscopy generates new view of fuel cells

16.08.2011
A novel microscopy method at the Department of Energy's Oak Ridge National Laboratory is helping scientists probe the reactions that limit widespread deployment of fuel cell technologies.

ORNL researchers applied a technique called electrochemical strain microscopy that enables them to examine the dynamics of oxygen reduction/evolution reactions in fuel cell materials, which may reveal ways to redesign or cut the costs of the energy devices. The team's findings were published in Nature Chemistry.


A new ORNL microscopy technique allows researchers to study key reactions in fuel cells at an unprecedented scale. The overlay shows electrochemical activity of platinum (Pt) nanoparticles on an yttria-stabilized zirconia (YSZ) surface, revealing enhanced activity along the triple-phase boundaries (TPB).

"If we can find a way to understand the operation of the fuel cell on the basic elementary level and determine what will make it work in the most optimum fashion, it would create an entirely new window of opportunity for the development of better materials and devices," said co-author Amit Kumar, a research scientist at ORNL's Center for Nanophase Materials Sciences.

Although fuel cells have long been touted as a highly efficient way to convert chemical energy into electrical energy, their high cost -- in large part due to the use of platinum as a catalyst -- has constrained commercial production and consumption.

Large amounts of platinum are used to catalyze the fuel cell's key reaction -- -the oxygen-reduction reaction, which controls the efficiency and longevity of the cell. Yet exactly how and where the reaction takes place had not been probed because existing device-level electrochemical techniques are ill suited to study the reaction at the nanoscale. ORNL co-author Sergei Kalinin explains that certain methods like electron microscopy had failed to capture the dynamics of fuel cell operation because their resolution was effectively too high.

"When you want to understand how a fuel cell works, you are not interested in where single atoms are, you're interested in how they move in nanometer scale volumes," Kalinin said. "The mobile ions in these solids behave almost like a liquid. They don't stay in place. The faster these mobile ions move, the better the material is for a fuel cell application. Electrochemical strain microscopy is able to image this ion mobility."

Other electrochemical techniques are unable to study oxygen-reduction reactions because they are limited to resolutions of 10's of microns - 10,000 times larger than a nanometer.

"If the reaction is controlled by microstructure features that are much finer than a micron, let's say grain boundaries or single extended defects that are affecting the reaction, then you will never be able to catch what is giving rise to reduced or enhanced functionality of the fuel cell," said ORNL's Stephen Jesse, builder of the ESM microscope. "You would like to do this probing on a scale where you can identify each of these defects and correlate the functionality of the cell with these defects."

Although this study mainly focuses on the introduction of a technique, researchers explain their approach as a much-needed bridge between a theoretical and applied understanding of fuel cells.

"There is a huge gap between fundamental science and applied science for energy-related devices like fuel cells and batteries," Kalinin said. "The semiconducting industry, for example, is developing exponentially because the link between application and basic science is very well established. This is not the case in energy systems. They are usually much more complicated than semiconductors and therefore a lot of development is driven by trial and error type of work."

Co-authors on the study are University of Heidelberg's Francesco Ciucci and Anna Morozovska from the National Academy of Science of Ukraine, whose theoretical analysis was critical in explaining the ESM measurements.

This research was conducted at the Center for Nanophase Materials Sciences at ORNL. CNMS is one of the five DOE Nanoscale Science Research Centers supported by the DOE Office of Science, premier national user facilities for interdisciplinary research at the nanoscale. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE's Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge and Sandia and Los Alamos national laboratories.

For more information about the DOE NSRCs, please visit http://science.energy.gov/bes/suf/user-facilities/nanoscale-science-research-centers/. ORNL is managed by UT-Battelle for the Department of Energy's Office of Science.

Morgan McCorkle | EurekAlert!
Further information:
http://www.ornl.gov

More articles from Materials Sciences:

nachricht Flying: Efficiency thanks to Lightweight Air Nozzles
23.10.2017 | Technische Universität Chemnitz

nachricht Strange but true: Turning a material upside down can sometimes make it softer
20.10.2017 | Universitat Autonoma de Barcelona

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>