Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Super stable garnet ceramics may be ideal for high-energy lithium batteries

22.10.2014

Scientists at the Department of Energy’s Oak Ridge National Laboratory have discovered exceptional properties in a garnet material that could enable development of higher-energy battery designs.

The ORNL-led team used scanning transmission electron microscopy to take an atomic-level look at a cubic garnet material called LLZO. The researchers found the material to be highly stable in a range of aqueous environments, making the compound a promising component in new battery configurations.


ORNL researchers used scanning transmission electron microscopy to take an atomic-level look at a cubic garnet material called LLZO that could help enable higher-energy battery designs.

Researchers frequently seek to improve a battery’s energy density by using a pure lithium anode, which offers the highest known theoretical capacity, and an aqueous electrolyte that can speedily transport lithium. The ORNL scientists believe the LLZO would be an ideal separator material, which is crucial.

“Many novel batteries adopt these two features [lithium anode and aqueous electrolyte], but if you integrate both into a single battery, a problem arises because the water is very reactive when in direct contact with lithium metal,” said ORNL postdoctoral associate Cheng Ma, first author on the team’s study published in Angewandte Chemie. “The reaction is very violent, which is why you need a protective layer around the lithium.”

Battery designers can use a solid electrolyte separator to shield the lithium, but their options are limited. Even the primary separator of choice, known as LAPT or LISICON, tends to break down under normal battery operating conditions.

“Researchers have searched for a suitable solid electrolyte separator material for years,” said ORNL’s Miaofang Chi, the study’s lead author. “The requirements for this type of material are very strict. It must be compatible with the lithium anode because lithium is reactive, and it also has to be stable over a wide pH range, because you can have an alkaline environment -- especially with lithium air batteries.”

The researchers used atomic resolution imaging to monitor structural changes in LLZO after the samples’ immersion in a range of aqueous solutions. The team’s observations showed that the compound remained structurally stable over time across neutral and extremely alkaline environments.

“This solid electrolyte separator remains stable even for a pH value higher than 14,” Ma said. “It gives battery designers more options for the selection of aqueous solutions and the catholyte.” Catholyte is the portion of the electrolyte close to the cathode.

In lithium-air batteries, for instance, researchers have previously tried to avoid the degradation of the separator by diluting the aqueous solutions, which only makes the battery heavier and bulkier. With this new type of solid electrolyte separator, there is no need to dilute the aqueous electrolyte, so it indirectly increases the battery’s energy density.

Higher-energy batteries are in demand for electrified transportation and electric grid energy storage applications, leading researchers to explore battery designs beyond the limits of lithium-ion technologies.

The researchers intend to continue their research by evaluating the LLZO garnet’s performance in an operating battery. Coauthors are ORNL’s Chengdu Liang, Karren More, Ezhiylmurugan Rangasamy, and Michigan State University’s Jeffrey Sakamoto. The study is published as “Excellent Stability of a Li-Ion-Conducting Solid Electrolyte upon Reversible Li+/H+ Exchange in Aqueous Solutions.”

This research was conducted in part at the Center for Nanophase Materials Sciences, a DOE Office of Science User Facility. The research was supported by DOE’s Office of Science.

UT-Battelle manages ORNL for the Department of Energy's Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit http://science.energy.gov/.

Morgan McCorkle | Eurek Alert!

More articles from Power and Electrical Engineering:

nachricht How protons move through a fuel cell
22.06.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

nachricht Fraunhofer IZFP acquires lucrative EU project for increasing nuclear power plant safety
21.06.2017 | Fraunhofer-Institut für Zerstörungsfreie Prüfverfahren IZFP

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>