University of South Carolina and Clemson reseachers uncover clean interfaces
Scientists from South Carolina's leading public universities--the University of South Carolina and Clemson University--have made a discovery that could dramatically improve the efficiency of batteries and fuel cells.
The research, which is published in the journal Nature Communications, involves improving the transport of oxygen ions, a key component in converting chemical reactions into electricity. The team studied a well-known material, gadolinium doped ceria (GDC), which transports oxygen ions and is currently in use as a solid oxide fuel cell electrolyte. Through the use of additives and a "smart" chemical reaction, they demonstrated a greatly enhanced conductivity in GDC. The result is a faster and more efficient conversion into electricity.
"This breakthrough will pave the path to fabricate next generation energy conversion and storage devices with significantly enhanced performance, increasing energy efficiency and making energy environmentally benign and sustainable," said Fanglin (Frank) Chen, a chemical engineering professor at the University of South Carolina.
"The origin of the low grain boundary conductivity is known to be segregation of gadolinium (Gd) in the grain boundary which leads to a built-in charge at the interface referred to as the space charge effect," Chen said. "This built in charge serves as a barrier for ion transport at the interface. The challenge is how to effectively avoid the segregation of Gd in the grain boundary. The grain boundary is extremely narrow, on the order of a few nano-meters. Therefore, it is extremely difficult to characterize and rationally control the amount of Gd in such a narrow region."
"In order to make 'clean' grain boundaries and avoid the segregation of Gd at the interface we have added an electronic conductor cobalt iron spinel (CFO), resulting in a composite structure," said Kyle Brinkman, a professor at Clemson University and co-author of the work.
"The CFO reacts with the excess Gd present in the grain boundary of GDC to form a third phase. It was found that this new phase could also serve as an excellent oxygen ionic conductor. We further investigated the atomic microstructure around the grain boundary through a series of high resolution characterization techniques and found that Gd segregation in the grain boundary had been eliminated, leading to dramatic improvement in the grain boundary oxygen ionic conductivity of GDC."
The improved oxygen ionic conductivity of GDC has been demonstrated in an oxygen permeation experiment where the elevated oxygen ion transport was used to separate pure oxygen from air at elevated temperatures. The approach of targeting emergent phases resulting in clean interfaces can be applied to a number of essential materials for energy conversion and storage devices used in handheld electronics, vehicles, and power plants, making them more cost-effective, efficient and environmentally friendly.
Currently, ceramic composites consisting of ionic and electronic conductive components like those in this study are under consideration for membrane separation devices that provide oxygen for enhanced conversion of coal and natural gas, as well as for membrane reactors used in natural gas conversion and recovery.
Other team members include Ye Lin and Shumin Fang, both from the University of South Carolina and Dong Su, a scientist at Brookhaven National Laboratory who contributed to the electron microscopy investigations.
Jeff Stensland | idw - Informationsdienst Wissenschaft
NASA CubeSat to test miniaturized weather satellite technology
10.11.2017 | NASA/Goddard Space Flight Center
New approach uses light instead of robots to assemble electronic components
08.11.2017 | The Optical Society
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
21.11.2017 | Physics and Astronomy
21.11.2017 | Physics and Astronomy
21.11.2017 | Life Sciences