Developers from Bosch and scientists at the Technical University of Munich (TUM) are using neutrons to analyze the filling of lithium ion batteries for hybrid cars with electrolytes. Their experiments show that electrodes are wetted twice as fast in a vacuum as under normal pressure.
One of the most critical and time-consuming processes in battery production is the filling of lithium cells with electrolyte fluid following the placement the of electrodes in a battery cell. While the actual filling process takes only a few seconds, battery manufacturers often wait several hours to ensure the liquid is fully absorbed into the pores of the electrode stack.
The fact that neutrons are hardly absorbed by the metal battery housing makes them ideal for analyzing batteries. That is why Bosch employees, in collaboration with scientists from the TU Munich and the University of Erlangen-Nuremberg, investigated the filling process at the neutron imaging and tomography facility ANTARES of the research neutron source FRM II.
Faster in a vacuum
Manufacturers of lithium cells often fill the empty cells in a vacuum. The process is monitored indirectly using resistance measurements. "To make sure that all the pores of the electrodes are filled with the electrolyte, manufacturers build in large safety margins," says Bosch developer Dr. Wolfgang Weydanz. "That costs time and money."
In the light of the neutrons, the scientists recognized that in a vacuum the electrodes were wetted completely in just over 50 minutes. Under normal pressure, this takes around 100 minutes. The liquid spreads evenly in the battery cell from all four sides, from the outside in.
In addition, the electrodes absorb ten percent less electrolyte under normal pressure. The culprit is gases that hinder the wetting process, as the scientists were able to demonstrate for the first time using the neutrons.
Visualization of electrolyte filling process and influence of vacuum during filling for hard case prismatic lithium ion cells by neutron imaging to optimize the production process
W.J. Weydanz, H. Reisenweber, A. Gottschalk, M. Schulz, T. Knoche, G. Reinhart, M. Masuch, J. Franke, R. Gilles
Journal of Power Sources, Volume 380, 15 March 2018, Pages 126–134, https://doi.org/10.1016/j.jpowsour.2018.01.081
Dr. Ralph Gilles
Technical University Munich
Research-Neutronsource Heinz Maier-Leibnitz (FRM II)
Phone: +49 89 289 14665
https://www.tum.de/nc/en/about-tum/news/press-releases/detail/article/34531/ Link to the press release
Link to the video: Elektrolyt-Befüllung von Lithiumionen-Akkus im Licht eines Neutronenstrahls
Dr. Ulrich Marsch | Technische Universität München
Magnetization reversal achieved at room temperature using only an electric field
22.02.2019 | Tokyo Institute of Technology
The holy grail of nanowire production
20.02.2019 | Ecole Polytechnique Fédérale de Lausanne
An international research team including astronomers from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has combined radio telescopes from five continents to prove the existence of a narrow stream of material, a so-called jet, emerging from the only gravitational wave event involving two neutron stars observed so far. With its high sensitivity and excellent performance, the 100-m radio telescope in Effelsberg played an important role in the observations.
In August 2017, two neutron stars were observed colliding, producing gravitational waves that were detected by the American LIGO and European Virgo detectors....
Up to now, OLEDs have been used exclusively as a novel lighting technology for use in luminaires and lamps. However, flexible organic technology can offer much more: as an active lighting surface, it can be combined with a wide variety of materials, not just to modify but to revolutionize the functionality and design of countless existing products. To exemplify this, the Fraunhofer FEP together with the company EMDE development of light GmbH will be presenting hybrid flexible OLEDs integrated into textile designs within the EU-funded project PI-SCALE for the first time at LOPEC (March 19-21, 2019 in Munich, Germany) as examples of some of the many possible applications.
The Fraunhofer FEP, a provider of research and development services in the field of organic electronics, has long been involved in the development of...
For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.
The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...
Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens
Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...
Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light
When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...
11.02.2019 | Event News
30.01.2019 | Event News
16.01.2019 | Event News
22.02.2019 | Physics and Astronomy
22.02.2019 | Materials Sciences
22.02.2019 | Life Sciences