# Soft x-ray transmission microscopy on lithium-rich layered-oxide cathode materials

Sorrentino, Andrea; Simonelli, Laura; Kazzazi, Arefehsadat; Laszczynski, Nina; Birrozzi, Agnese; Mullaliu, Angelo; Pereiro, Eva; Passerini, Stefano; Giorgetti, Marco; Tonti, Dino

##### Abstract:
Energy-dependent full field transmission soft X-ray microscopy (TXM) is able to give a full picture at the nanometer scale of the chemical state and spatial distribution of oxygen and other elements relevant for battery materials, providing pixel-by-pixel absorption spectrum. We show different methods to localize chemical inhomogeneities in Li$_{1.2}$Mn$_{0.56}$Ni$_{0.16}$Co$_{0.08}$O$_{2}$ particles with and without VOx coating extracted from electrodes at different states of charge. Considering the 3d(Mn,Ni)-2p(O) hybridization, it has been possible to discriminate the chemical state of Mn and Ni in addition to the one of O. Different oxidation states correspond to specific features in the O-K spectra. To localize sample regions with specific compositions we apply two different methods. In the first, the pixel-by-pixel ratios of images collected at different key energies clearly highlight local inhomogeneities. In the second, introduced here for the first time, we directly correlate corresponding pixels of the two images on a xy scatter plot that we call phase map, where we can visualize the distributions as function of thickness as well as absorption artifacts. ... mehr

 Zugehörige Institution(en) am KIT Karlsruher Institut für Technologie (KIT) Publikationstyp Zeitschriftenaufsatz Publikationsjahr 2021 Sprache Englisch Identifikator ISSN: 2076-3417 KITopen-ID: 1000131402 Erschienen in Applied Sciences (Switzerland) Verlag MDPI Band 11 Heft 6 Seiten Art.-Nr.: 2791 Nachgewiesen in Scopus
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