Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sulfur in every pore

11.04.2012
Improved batteries with carbon nanoparticles

From smartphones to e-bikes, the number of mobile electronic devices is steadily growing around the world. As a result, there is an increased need for batteries that are small and light, yet powerful. As the potential for the further improvement of lithium-ion batteries is nearly exhausted, experts are now turning to a new and promising power storage device: lithium-sulfur batteries.

In an important step toward the further development of this type of battery, a team led by Professor Thomas Bein of LMU Munich and Linda Nazar of Waterloo University in Canada has developed porous carbon nanoparticles that utilize sulfur molecules to achieve the greatest possible efficiency. (Angewandte Chemie, April 2012)

In prototypes of the lithium-sulfur battery, lithium ions are exchanged between lithium- and sulfur-carbon electrodes. The sulfur plays a special role in this system: Under optimal circumstances, it can absorb two lithium ions per sulfur atom. It is therefore an excellent energy storage material due to its low weight. At the same time, sulfur is a poor conductor, meaning that electrons can only be transported with great difficulty during charging and discharging. To improve this battery's design the scientists at Nanosystems Initiative Munich (NIM) strive to generate sulfur phases with the greatest possible interface area for electron transfer by coupling them with a nanostructured conductive material.

To this end, Thomas Bein and his team at NIM first developed a network of porous carbon nanoparticles. The nanoparticles have 3- to 6-nanometer wide pores, allowing the sulfur to be evenly distributed. In this way, almost all of the sulfur atoms are available to accept lithium ions. At the same time they are also located close to the conductive carbon.

"The sulfur is very accessible electrically in these novel and highly porous carbon nanoparticles and is stabilized so that we can achieve a high initial capacity of 1200 mAh/g and good cycle stability," explains Thomas Bein. "Our results underscore the significance of nano-morphology for the performance of new energy storage concepts."

The carbon structure also reduces the so-called polysulfide problem. Polysulfides form as intermediate products of the electrochemical processes and can have a negative impact on the charging and discharging of the battery. The carbon network binds the polysulfides, however, until their conversion to the desired dilithium sulfide is achieved. The scientists were also able to coat the carbon material with a thin layer of silicon oxide which protects against polysulfides without reducing conductivity.

Incidentally, the scientists have also set a record with their new material: According to the latest data, their material has the largest internal pore volume (2.32 cm3/g) of all mesoporous carbon nanoparticles, and an extremely large surface area of 2445 m2/g. This corresponds roughly to an object with the volume of a sugar cube and the surface of ten tennis courts. Large surface areas like this might soon be hidden inside our batteries.

Publication:
"Spherical Ordered Mesoporous Carbon Nanoparticles with Extremely High Porosity for Lithium-Sulfur Batteries". Jörg Schuster, Guang He, Benjamin Mandlmeier, Taeeun Yim, Kyu Tae Lee, Thomas Bein and Linda F. Nazar.
In: Angewandte Chemie, Article first published online: 1 MAR 2012
doi: 10.1038/nm.2720
Contact:
Prof. Thomas Bein
Chair of Physical Chemistry
Phone: +49 89 2180 77621
Email: tbein@cup.uni-muenchen.de

Dr. Kathrin Bilgeri | EurekAlert!
Further information:
http://www.lmu.de
http://bein.cup.uni-muenchen.de

More articles from Life Sciences:

nachricht Research team creates new possibilities for medicine and materials sciences
22.01.2018 | Humboldt-Universität zu Berlin

nachricht Saarland University bioinformaticians compute gene sequences inherited from each parent
22.01.2018 | Universität des Saarlandes

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Thanks for the memory: NIST takes a deep look at memristors

22.01.2018 | Materials Sciences

Radioactivity from oil and gas wastewater persists in Pennsylvania stream sediments

22.01.2018 | Earth Sciences

Saarland University bioinformaticians compute gene sequences inherited from each parent

22.01.2018 | Life Sciences

VideoLinks Wissenschaft & Forschung
Overview of more VideoLinks >>>