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MM: Fachverband Metall- und Materialphysik

MM 2: Computational Materials Modelling: Energy Materials

MM 2.6: Talk

Monday, September 5, 2022, 11:45–12:00, H44

Ab-initio core spectroscopy of LiCoO2 and CoO2 — Daniel Duarte Ruiz and •Caterina Cocchi — Carl von Ossietzky Universität Oldenburg, Institut für Physik, Oldenburg, Deutschland

X-ray absorption spectroscopy (XAS) is one of the most widely used technique to study the electronic structure of cathode active materials in operando conditions. From a theoretical point of view, many-body perturbation theory on top of density-functional theory [1] is the state of the art in the prediction of XAS and in the interpretation of corresponding experimental results. In this work, we investigate core spectroscopy in LiCoO2 and CoO2, considering excitations from the Co K- and L23-edges as well as from the O K-edge. Our results, in agreement with experimental data, indicate that excitonic effects are negligible for the absorption spectra. The spectral fingerprints are well reproduced already by the independent particle approximation and, on a qualitative level, by the atomic, orbital features in the projected density states. These findings suggest that monitoring the electronic structure of LiCoO2 during the delithiation process is sufficient to capture the evolution of XAS signatures even in a possible high-throughput fashion.

[1] C. Vorwerk et al. Electron. Struc. 1, 037001 (2019)