My watch list
my.chemeurope.com  
Login  

Turbocharge for lithium batteries

11-Jun-2018

Copyright: Forschungszentrum Jülich / Sascha Kreklau

This is Prof. Dina Fattakhova-Rohlfing.

Lithium-ion batteries are the ultimate benchmark when it comes to mobile phones, tablet devices, and electric cars. Their storage capacity and power density are far superior to other rechargeable battery systems. Despite all the progress that has been made, however, smartphone batteries only last a day and electric cars need hours to be recharged. Scientists are therefore working on ways to improve the power densities and charging rates of all-round batteries. "An important factor is the anode material," explains Dina Fattakhova-Rohlfing from the Institute of Energy and Climate Research (IEK-1).

"In principle, anodes based on tin dioxide can achieve much higher specific capacities, and therefore store more energy, than the carbon anodes currently being used. They have the ability to absorb more lithium ions," says Fattakhova-Rohlfing. "Pure tin oxide, however, exhibits very weak cycle stability - the storage capability of the batteries steadily decreases and they can only be recharged a few times. The volume of the anode changes with each charging and discharging cycle, which leads to it crumbling."

One way of addressing this problem is hybrid materials or nanocomposites - composite materials that contain nanoparticles. The scientists developed a material comprising tin oxide nanoparticles enriched with antimony, on a base layer of graphene. The graphene basis aids the structural stability and conductivity of the material. The tin oxide particles are less than three nanometres in size - in other words less than three millionths of a millimetre - and are directly "grown" on the graphene. The small size of the particle and its good contact with the graphene layer also improves its tolerance to volume changes - the lithium cell becomes more stable and lasts longer.

Three times more energy in one hour

"Enriching the nanoparticles with antimony ensures the material is extremely conductive," explains Fattakhova-Rohlfing. "This makes the anode much quicker, meaning that it can store one-and-a-half times more energy in just one minute than would be possible with conventional graphite anodes. It can even store three times more energy for the usual charging time of one hour."

"Such high energy densities were only previously achieved with low charging rates," says Fattakhova-Rohlfing. "Faster charging cycles always led to a quick reduction in capacity." The antimony-doped anodes developed by the scientists, however, retain 77 % of their original capacity even after 1,000 cycles.

"The nanocomposite anodes can be produced in an easy and cost-effective way. And the applied concepts can also be used for the design of other anode materials for lithium-ion batteries," explains Fattakhova-Rohlfing. "We hope that our development will pave the way for lithium-ion batteries with a significantly increased energy density and very short charging time."

Facts, background information, dossiers
  • anode materials
More about Forschungszentrum Jülich
  • News

    Flipping the electron spin

    When lithium-ion batteries are charged too quickly, metallic lithium gets deposited on the anodes. This reduces battery capacity and lifespan and can even destroy the batteries. Scientists at the Forschungszentrum Jülich and the Technical University of Munich (TUM) have now presented a proc ... more

    The repulsion trick

    Jülich researchers have succeeded in controlling the growth of organic molecules using a special trick. Molecules that repel each other play a key role in this process: due to their opposing forces, they always keep a certain distance from their neighbours. Therefore, they mix easily with a ... more

    New electron source for materials analysis

    How can solar cells be made more efficient? How can solar and wind energy be best stored for later use? Technologies for the transformation of the German energy sector (Energiewende) require tailor-made materials which are both affordable and efficient. One important tool in the search for ... more

  • Companies

    Forschungszentrum Jülich GmbH, Projektträger Jülich

    Supporting the Federal Ministry of Education and Research (BMBF), Economics and Technology (BMWA), Environment (BMU) and several Federal States in funding of research. more

Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE