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Specialized iNANO Lecture: Spatially Resolved Micro-XRF Applied on Electrodes for Li-Ion Batteries

Dr. Ulrike Boesenberg, PETRA III, Deutsches Elektronen-Synchrotron, Hamburg, Germany

Info about event

Time

Tuesday 9 December 2014,  at 11:15 - 12:00

Location

Meeting room 1590-213, iNANO, GGustav Wieds Vej 14, 8000 Aarhus C

Dr. Ulrike Boesenberg

Dr. Ulrike Boesenberg, PETRA III, Deutsches Elektronen-Synchrotron, Hamburg, Germany

Spatially Resolved Micro-XRF Applied on Electrodes for Li-Ion Batteries

Scanning X-ray microscopy is a very powerful tool to investigate the interior of an object without destructive sample preparation. At the P06 micro-endstation at the PETRA III storage ring at DESY in Hamburg, Germany, hard X-ray beam sizes down to the 300nm level are used for scanning microscopy with an optimized setup for µ-fluorescence imaging.

Visualization of spatial correlation between morphological properties and chemical phase can help to find origins of aging and failure mechanism in Li-ion batteries and finally, to build better batteries. Micro X-ray fluorescence analysis allows for chemical imaging of elemental distributions of multiple 3d elements simultaneously, or distribution of the state of charge. Making use of the fairly large penetration length of the X-rays, representative volumes of the electrodes can be studied.

Cutting edge instrumentation in this field is the Maia fluorescence detector. It allows for ultra- fast mapping of areas of multiple mm² area with sub-micron resolution within minutes. For the present study, samples of LiNi0.5Mn1.5O4 electrodes cycled vs. Li or graphite were investigated at beamline P06 at DESY, Hamburg. The experiments revealed significant inhomogeneities in the local Ni/Mn ratio upon cycling which is correlated to thinning of the electrode.


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Host: Assistant professor Dorthe Ravnsbæk, Interdisciplinary Nanoscience Center, Aarhus University