Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Batteries with better performance and improved safety

23.11.2017

Researchers from Empa and the University of Geneva have developed a prototype of a novel solid sodium battery with the potential to store extra energy.

Phones, laptops, electric cars – batteries are everywhere. And to meet the expectations of today’s consumers, these batteries are increasin­gly lighter, more powerful and designed to last longer. Currently the core technology for these applications is lithium ion batteries. But the technology is expensive and contains a flammable liquid, which may represent a safety hazard, when the battery is abused.


Composition of the solid sodium battery.

Empa

To satisfy the growing demand from emerging markets (electric cars, for example, and renewable energy storage), researchers from Empa, the Swiss Federal Laboratories for Materials Science and Technology, and the University of Geneva (UNIGE) have devised a new battery prototype: known as «all-so­lid-state», this battery has the potential to store more energy while maintaining high safety and reliability levels. Furthermore, the bat­tery is based on sodium, a cheap alternative to lithium. Read about the research in more detail in the journal Energy and Environmental Science.

For a battery to work, it must have the following three key compo­nents: an anode (the negative pole), a cathode (the positive pole) and an electrolyte. Most of the batteries used in our electronic equip­ment today are based on lithium ions.

When the battery charges, the lithium ions leave the cathode and move to the anode. To prevent lithium dendrites forming – a kind of microscopic stalagmite that can induce short circuits in the battery that may cause fire – the anode in commercial batteries consists of graphite rather than metallic li­thium, even though this ultra-light metal would increase the amount of energy that can be stored.

The Empa and UNIGE researchers focused on the advantages of a «solid» battery to cope with the heightened demand from emerging markets and to make batteries with even better performance: fas­ter charging together with increased storage capacity and improved safety. Their battery uses a solid instead of a liquid electrolyte that enables the use of a metal anode by blocking the formation of den­drites, making it possible to store more energy while guaranteeing safety.

A non-flammable solid sodium battery

«But we still had to find a suitable solid ionic conductor that, as well as being non-toxic, was chemically and thermally stable, and that would allow the sodium to move easily between the anode and the cathode,» explains Hans Hagemann, professor in the Physical Che­mistry Department in UNIGE’s Faculty of Sciences. The researchers discovered that a boron-based substance, a closo-borane, enabled the sodium ions to circulate freely. Furthermore, since the closo-borane is an inorganic conductor, it removes the risk of the battery catching fire while recharging. It is a material, in other words, with numerous promising properties.

«The difficulty was establishing close contact between the battery’s three layers: the anode, consisting of solid metallic sodium; the ca­thode, a mixed sodium chromium oxide; and the electrolyte, the clo­so-borane,» states Léo Duchêne, a researcher at Empa’s Materials for Energy Conversion lab and a PhD student in the Department of Physical Chemistry at UNIGE’s Faculty of Science. The researchers dissolved part of the battery electrolyte in a solvent before adding the sodium chromium oxide powder. Once the solvent had evaporated, they stacked the cathode powder composite with the electrolyte and anode, compressing the various layers to form the battery.

The team then tested the battery. «The electro-chemical stability of the electrolyte we are using here can withstand three volts, whereas many solid electrolytes previously studied are damaged at the same voltage,» says Arndt Remhof, a re­searcher at Empa and leader of the project, which is supported by the Swiss National Science Foundation (SNSF) and the Swiss Competence Centre for Energy Research on Heat and Electricity Storage (SCCER-HaE).

The scientists also tested the battery over 250 charge and discharge cycles, after which 85% of the energy capacity was still functional. «But it needs 1,200 cycles before the battery can be put on the market», say the researchers. «In addition, we still have to test the battery at room temperature so we can confirm whether or not den­drites form, while increasing the voltage even more. Our experiments are still ongoing.»

Weitere Informationen:

https://www.empa.ch/web/s604/solid-state-battery

Karin Weinmann | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

Further reports about: battery better performance cathode conductor electric cars electrolyte ions lithium ions sodium

More articles from Power and Electrical Engineering:

nachricht Researchers take next step toward fusion energy
16.11.2017 | Texas A&M University

nachricht Desert solar to fuel centuries of air travel
16.11.2017 | SolarPACES

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: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>