Disentangling the anionic and cationic redox in Li-rich layered oxide by XRS and XES

The aim of this proposal is to study the electronic state of the three redox centres (Mn, Ni, and O) involved in the electrochemical mechanism of Li1.2Mn0.6Ni0.2O2 (LLMNO), a Li-rich layered oxide high-capacity positive electrode material for Li-ion batteries. Mn and O will be probed by ex situ X-ray Raman Scattering (XRS) at the O K-edge and the Mn L2,3-edges, whereas the state of Ni will be studied by Kbeta X-ray emission spectroscopy (XES). By combining all the results, we aim to directly follow the charge contribution of the different cationic and anionic redox centres (Mn, Ni, and O) at different stages of the electrochemical cycling. By coupling these results to ab initio calculations, we will be able to monitor the reorganization of TMs unoccupied electronic states close to the Fermi level, providing a clear description of the electronic structure of the TM-O bonding during battery cycling.