Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanomaterials: Peapod power

09.02.2011
A new type of composite material with peapod structures can help improve the performance of lithium-ion batteries

Lithium-ion batteries are used to power a wide range of electronic devices, including computers, cameras, digital audio players and calculators. Tremendous effort has been devoted to the development of lithium-ion batteries, especially in improving the efficiency and integrity of the battery electrodes.


Cobalt oxide nanoparticles embedded in carbon fibers (left) to form peapod-like structures improve the lifetime of electrodes in lithium-ion batteries.
Copyright : Left: 2010 ACS. Right: iStockphoto.com/pixhook

This is because during the discharging and charging processes, lithium ions are repeatedly incorporated into and extracted from the electrodes by alloy formation or chemical conversion. These recurring events are known to cause the progressive degradation of the electrodes, irreversibly damaging battery performance.

Yu Wang at the A*STAR Institute of Chemical and Engineering Sciences and co-workers[1] have now demonstrated an elegant strategy to reduce the degradation problem and increase the capacity retention of lithium-ion batteries over many charge–discharge cycles. The strategy involves the use of a composite material with a peapod structure comprising cobalt oxide (Co3O4) nanoparticles embedded in carbon fibers (see image).

Cobalt oxide is a promising material for anodes in lithium-ion batteries because its capacity for holding ions is higher than that of conventional electrode materials, such as tin. In addition, Co3O4 can be easily converted to LiCoO2, which is the material currently used in commercial cathodes. The researchers made the peapod structures by heating cobalt carbonate hydroxide nanobelts coated with layers of polymerized glucose in an inert atmosphere at 700 ºC and then in air at 250 ºC. Electrodes built using the peapod composite had enhanced lithium storage and capacity retention—delivering 91% of the total possible capacity after 50 charge–discharge cycles.

“The Co3O4 nanoparticles act as active materials to store lithium ions and the hollow carbon fibers protect and prevent the Co3O4 nanoparticles from aggregating and collapsing,” says Wang. The carbon fibers also play the role of conducting electrons from the nanoparticles.

According to Wang, aside from the promising application in lithium-ion batteries, the fabrication of the peapod composite is an achievement in itself, as it is the first time that such isolated magnetic nanoparticles embedded in hollow fibers have been produced. Scanning electron microscopy revealed that the peapod composite exhibits a uniform morphology, with pod lengths of up to several micrometers and pod diameters of as small as 50 nanometers. The researchers believe that their method could be extended to generate encapsulated nanoparticles using a wide range of materials with applications beyond lithium-ion batteries, for example, in gene engineering, catalysis, gas sensing and the manufacture of capacitors and magnets.

The A*STAR-affiliated researchers contributing to this research are from the Institute of Chemical and Engineering Sciences.

Journal information

[1] Wang, Y. et al. Designed functional systems from peapod-like Co@carbon to Co3O4@carbon nanocomposites. ACS Nano 4, 4753–4761 (2010).

Lee Swee Heng | Research asia research news
Further information:
http://www.research.a-star.edu.sg/research/6282
http://www.researchsea.com

More articles from Materials Sciences:

nachricht New design improves performance of flexible wearable electronics
23.06.2017 | North Carolina State University

nachricht Plant inspiration could lead to flexible electronics
22.06.2017 | American Chemical Society

All articles from Materials Sciences >>>

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

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

New photoacoustic technique detects gases at parts-per-quadrillion level

28.06.2017 | Physics and Astronomy

Funding of Collaborative Research Center developing nanomaterials for cancer immunotherapy extended

28.06.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>