Soft X-ray Transmission Microscopy on Lithium-Rich Layered-Oxide Cathode Materials
| Autor: | Laura Simonelli, Andrea Sorrentino, Stefano Passerini, Arefehsadat Kazzazi, Eva Pereiro, Dino Tonti, Agnese Birrozzi, Angelo Mullaliu, Nina Laszczynski, Marco Giorgetti |
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| Přispěvatelé: | Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Helmholtz Association, Sorrentino A., Simonelli L., Kazzazi A., Laszczynski N., Birrozzi A., Mullaliu A., Pereiro E., Passerini S., Giorgetti M., Tonti D. |
| Rok vydání: | 2021 |
| Předmět: |
Chemical imaging
DDC 540 / Chemistry & allied sciences Interkalation Ratio of normal variable full-field transmission microscopy 02 engineering and technology 01 natural sciences lcsh:Technology Spectral line Batterie lcsh:Chemistry Coating Microscopy Intercalation General Materials Science Composition distribution Arctangent Computer science information & general works Absorption (electromagnetic radiation) Instrumentation lcsh:QH301-705.5 Fluid Flow and Transfer Processes General Engineering Stray light Chemical mapping 021001 nanoscience & nanotechnology lcsh:QC1-999 Computer Science Applications composition distribution ddc:540 Intercalations chemical mapping 0210 nano-technology Materials science Absorption spectroscopy batteries Stray Radiation engineering.material 010402 general chemistry Molecular physics ratio of normal variables Batteries Ratio of normal variables intercalation stray light lcsh:T Process Chemistry and Technology Electric batteries 0104 chemical sciences Chemical state Full-field transmission microscopy lcsh:Biology (General) lcsh:QD1-999 arctangent lcsh:TA1-2040 ddc:000 engineering Particle lcsh:Engineering (General). Civil engineering (General) lcsh:Physics |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname Applied Sciences, Vol 11, Iss 2791, p 2791 (2021) Applied Sciences Volume 11 Issue 6 Applied Sciences (Switzerland), 11 (6), Art.-Nr.: 2791 |
| ISSN: | 2076-3417 |
| Popis: | 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 Li1.2Mn0.56Ni0.16Co0.08O2 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. We can select groups of pixels, and then map regions with similar spectral features. Core-shell distributions of composition are clearly shown in these samples. The coating appears in part to frustrate some of the usual chemical evolution. In addition, we could directly observe several further aspects, such as: distribution of conducting carbon; inhomogeneous state of charge within the electrode; molecular oxygen profiles within a particle. The latter suggests a surface loss with respect to the bulk but an accumulation layer at intermediate depth that could be assigned to retained O2. This research was funded by Spanish Government, through the “Severo Ochoa” Programme for Centers of Excellence in R&D (FUNFUTURE CEX2019-000917-S), and the projects MAT2017-91404-EXP, RTI2018-096273-B-I00 and RTI2018-097753-B-I00 with FEDER cofunding. D.T. participates in the FLOWBAT 2021 platforms promoted by the Spanish National Research Council (CSIC). The HIU authors acknowledge the basic funding from the Helmholtz Association. |
| Databáze: | OpenAIRE |
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