141HIGHLIGHTS 2020

Fig. 122: a,b) Galvanostatic cycling of electrodes based on CeO2 (black) and Ce0.9Fe0.1O2 (red) in half-cell configuration, i.e., with metallic lithium serving as counter electrode. c,d) In-situ XRD analysis of (c) pure CeO2 and (d) Ce0.9Fe0.1O2 in the same cell configuration.

Fig. 123: a-c) Ex-situ XANES data obtained for CeO2 and Ce0.9Fe0.1O2: the Ce LIII-edge for the pristine material and after lithiation for (a) CeO2 and (b) Ce0.9Fe0.1O2; (c) the Fe K-edge for the pristine material and after lithiation.

d,e) Ex-situ EXAFS spectra and the corresponding multi-parameter fit for pristine and lithiated Ce0.9Fe0.1O2.