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nanotimes News in Brief
The Fraunhofer ITWM re- searchers have managed to simulate on macroscopic and microscopic level the entire battery cell as well as the transport and reac- tion processes of the lithi- um ions themselves. “We can show the microscopic structure of the electrodes. Every individual pore measuring 10 micrometers can be seen – something none of today’s off-the-shelf programs can do. The position and shape of the electrodes can also be va- ried,” says Zausch. By resolving the structure of the electrodes in three dimensions, parameters such as lithium ion concentrations and current density can be calculated. For these computations a specializes “Finite Volume” code is used that was developed and implemented at the ITWM. The distribution of the current flow provides an indication of heat pro- duction in the battery. Therefore, the software can pinpoint possible hotspots that may overheat and can lead to ignition of the battery. Aging effects can also be assessed using BEST. After all, temperature development within the battery affects its service life. The scientists intend to upgrade the program to include aging models which would make these kinds of studies even easier to conduct.
“Ultimately, BEST should help both automakers and manufacturers of electric storage devices to build robust, safe batteries with greater range and, at the same time, improved acceleration,” says Zausch in conclusion.
11-02/03 :: February / March 2011
© ITWM, FHG
Contact: Dr. Jochen Zausch, Fraunhofer Institute for Indus- trial Mathematics, Germany:
http://www.itwm.fraunhofer.de
Infectious diseases researchers at Umeå University in Sweden are studying the surface properties of bacteria together with materials scientists. Studies of the outermost parts of the cell walls of bacteria yield new information about the chemical composi- tion of structures that are important for the capacity of bacteria to infect organisms. Chemist Madeleine Ramstedt is pursuing research on a material with new properties that prevent bacteria from attaching to its surface. The new material would be optimal for equipment in health care, where biofilms of bacteria can be a source of infection. In her re- search, Madeleine Ramstedt uses spectroscopic methods, among others, that she is now making available to her colleagues in the research consorti- um Umeå Centre for Microbial Research, UCMR. Microbiologists Sun Nyunt Wai, Ryoma Nakao, and Bernt Eric Uhlin, together with chemists Jean-
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