Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Engineer Improves Rechargeable Batteries with MoS2 Nano 'Sandwich'

17.04.2015

The key to better cellphones and other rechargeable electronics may be in tiny "sandwiches" made of nanosheets, according to mechanical engineering research from Kansas State University.

Gurpreet Singh, assistant professor of mechanical and nuclear engineering, and his research team are improving rechargeable lithium-ion batteries. The team has focused on the lithium cycling of molybdenum disulfide, or MoS2, sheets, which Singh describes as a "sandwich" of one molybdenum atom between two sulfur atoms.


Kansas State University

Molybdenum disulfide sheets — which are "sandwiches" of one molybdenum atom between two sulfur atoms — may improve rechargeable lithium-ion batteries, according to the latest research from Gurpreet Singh, Kansas State University assistant professor of mechanical and nuclear engineering.

In the latest research, the team has found that silicon carbonitride-wrapped molybdenum disulfide sheets show improved stability as a battery electrode with little capacity fading.

The findings appear in Nature's Scientific Reports in the article "Polymer-Derived Ceramic Functionalized MoS2Composite Paper as a Stable Lithium-Ion Battery Electrode." Other Kansas State University researchers involved include Lamuel David, doctoral student in mechanical engineering, India; Uriel Barrera, senior in mechanical engineering, Olathe; and Romil Bhandavat, 2013 doctoral graduate in mechanical engineering.

In this latest publication, Singh's team observed that molybdenum disulfide sheets store more than twice as much lithium — or charge — than bulk molybdenum disulfide reported in previous studies. The researchers also found that the high lithium capacity of these sheets does not last long and drops after five charging cycles.

"This kind of behavior is similar to a lithium-sulfur type of battery, which uses sulfur as one of its electrodes," Singh said. "Sulfur is notoriously famous for forming intermediate polysulfides that dissolve in the organic electrolyte of the battery, which leads to capacity fading. We believe that the capacity drop observed in molybdenum disulfide sheets is also due to loss of sulfur into the electrolyte."

To reduce the dissolution of sulfur-based products into the electrolyte, the researchers wrapped the molybdenum disulfide sheets with a few layers of a ceramic called silicon carbonitride, or SiCN. The ceramic is a high-temperature, glassy material prepared by heating liquid silicon-based polymers and has much higher chemical resistance toward the liquid electrolyte, Singh said.

"The silicon carbonitride-wrapped molybdenum disulfide sheets show stable cycling of lithium-ions irrespective of whether the battery electrode is on copper foil-traditional method or as a self-supporting flexible paper as in bendable batteries," Singh said.

After the reactions, the research team also dissembled and observed the cells under the electron microscope, which provided evidence that the silicon carbonitride protected against mechanical and chemical degradation with liquid organic electrolyte.

Singh and his team now want to better understand how the molybdenum disulfide cells might behave in an everyday electronic device — such as a cellphone — that is recharged hundreds of times. The researchers will continue to test the molybdenum disulfide cells during recharging cycles to have more data to analyze and to better understand how to improve rechargeable batteries.

Other research by Singh's team may help improve high temperature coatings for aerospace and defense. The engineers are developing a coating material to protect electrode materials against harsh conditions, such as turbine blades and metals subjected to intense heat.

The research appears in the Journal of Physical Chemistry. The researchers showed that when silicon carbonitride and boron nitride nanosheets are combined, they have high temperature stability and improved electrical conductivity. Additionally, these silicon carbonitride/boron nitride nanosheets are better battery electrodes, Singh said.

"This was quite surprising because both silicon carbonitride and boron nitride are insulators and have little reversible capacity for lithium-ions," Singh said. "Further analysis showed that the electrical conductivity improved because of the formation of a percolation network of carbon atoms known as 'free carbon' that is present in the silicon carbonitride ceramic phase. This occurs only when boron nitride sheets are added to silicon carbonitride precursor in its liquid polymeric phase before curing is achieved."

For both projects, the researchers have received support from the National Science Foundation.

Read more at http://www.k-state.edu/media/newsreleases/apr15/singh41615.html

Contact Information
Gurpreet Singh
785-532-7085
gurpreet@k-state.edu

Gurpreet Singh | newswise

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: 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)...

Im Focus: Optoelectronic Inline Measurement – Accurate to the Nanometer

Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.

New Manufacturing Technologies for New Products

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

A new technique isolates neuronal activity during memory consolidation

22.06.2017 | Life Sciences

Plant inspiration could lead to flexible electronics

22.06.2017 | Materials Sciences

A rhodium-based catalyst for making organosilicon using less precious metal

22.06.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>