- Number 323 |
- October 25, 2010
A closer look at a fuel cell in operation
Model fuel cell measured in situ
Measuring a fuel cell’s overall performance is relatively easy, but measuring its components individually as they work together is a challenge. That’s because one of the best experimental techniques for investigating the details of an electrochemical device while it’s operating is x-ray photoelectron spectroscopy (XPS). Traditional XPS works only in a vacuum, while fuel cells need gases under pressure to function.
Now a team of scientists from DOE’s Lawrence Berkeley National Laboratory, the University of Maryland, and Sandia National Laboratories and has used a new kind of XPS, called ambient-pressure XPS (APXPS), to examine every feature of a working solid oxide electrochemical cell. The tests were made at the Advanced Light Source (ALS) while the sample cell operated in an atmosphere of hydrogen and water vapor at one millibar pressure (about one-thousandth atmospheric pressure) and at very high temperatures, up to 750° Celsius (1,382 degrees Fahrenheit).The in situ experiments allowed the team to pinpoint the electroactive regions, measure length scales of electron transport through mixed ionic-electronic conductors, and map out potential losses across the entire cell. The remarkable APXPS detectors invented at Berkeley Lab made the challenging measurements possible for the first time.
[Paul Preuss, 510.486.6249,