 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
| . |  |
. |
 by Staff Writers Chicago IL (SPX) Mar 06, 2018
Researchers from the University of Illinois at Chicago and Lawrence Berkeley National Laboratory have developed a new technique that lets them pinpoint the location of chemical reactions happening inside lithium-ion batteries in three dimensions at the nanoscale level. Their results are published in the journal Nature Communications. "Knowing the precise locations of chemical reactions within individual nanoparticles that are participating in those reactions helps us to identify how a battery operates and uncover how the battery might be optimized to make it work even better," said Jordi Cabana, associate professor of chemistry at UIC and co-corresponding author on the paper. As a battery charges and discharges, its electrodes - the materials where the reactions that produce energy take place - are alternately oxidized and reduced. The chemical pathways by which these reactions take place help determine how quickly a battery becomes depleted. Tools available to study these reactions can only provide information on the average composition of electrodes at any given point in time. For example, they can let a researcher know what percentage of the electrode has become permanently oxidized. But these tools cannot provide information on the location of oxidized portions in the electrode. Because of these limitations, it is not possible to tell if reactions are confined to a certain area of the electrode, such as the surface of the material, or if reactions are taking place uniformly throughout the electrode. "Being able to tell if there is a tendency for a reaction to take place in a specific part of the electrode, and better yet, the location of reactions within individual nanoparticles in the electrode, would be extremely useful because then you could understand how those localized reactions correlate with the behavior of the battery, such as its charging time or the number of recharge cycles it can undergo efficiently," Cabana said. The new technique, called X-ray ptychographic tomography, came about through a partnership between chemists at UIC and scientists at the Advanced Light Source, at Lawrence Berkeley National Laboratory in California. Advanced Light Source scientists developed the instrumentation and measurement algorithms, which were used to help answer fundamental questions about battery materials and behavior identified by the UIC team. Together, the two teams used the tomographic technique to look at tens of nanoparticles of lithium-iron phosphate recovered from a battery electrode that had been partially charged. The researchers used a coherent, nanoscale beam of X-rays generated by the high-flux synchrotron accelerator at the Advanced Light Source to interrogate each nanoparticle. The pattern of absorption of the beam by the material gave the researchers information about the oxidation state of iron in the nanoparticles in the X-ray beam. Because they were able to move the beam just a few nanometers over and run their interrogation again, the team could reconstruct chemical maps of the nanoparticles with a resolution of about 11 nanometers. By rotating the material in space, they could create a three-dimensional tomographic reconstruction of the oxidation states of each nanoparticle. In other words, they could tell the extent to which an individual nanoparticle of lithium iron phosphate had reacted. "Using our new technique, we could not only see that individual nanoparticles showed different extents of reaction at a given time, but also how the reaction worked its way through the interior of each nanoparticle," Cabana said.
A lithium battery that operates at -70 degrees Celsius, a record low Washington DC (SPX) Mar 02, 2018 Researchers in China have developed a battery with organic compound electrodes that can function at -70 degrees Celsius - far colder than the temperature at which lithium-ion batteries lose most of their ability to conduct and store energy. The findings, published February 28 in the journal Joule, could aid engineers in developing technology suited to withstand the coldest reaches of outer space or the most frigid regions on Earth. While batteries can operate in relatively cold climates, they have ... read more
|
|||||||||||||
|
|
| The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - 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. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |
del.icio.us
Digg
Reddit
Google
