Fig. 4: Ex situ and in situ physicochemical characterizations of LMO and EI-LMO electrodes in the first Li metal coin cell cycle at 14.8 mA g-1 and 25°C.
From: Entropy-increased LiMn2O4-based positive electrodes for fast-charging lithium metal batteries
a, b Ex situ Mn K-edge XANES spectra of LMO a and EI-LMO b in pristine and 4.3 V-charged states. The 4.3 V-charged state represents the 100% state-of-charge. The insets highlight the variations in Mn valence states between the pristine and 100% SOC for both LMO and EI-LMO electrodes. c, d Ex situ Mn K-edge EXAFS spectra of LMO c and EI-LMO d in pristine and 4.3 V-charged states (100% SOC). e, f Waterfall plots for in situ high resolution XRD of LMO e and EI-LMO f, respectively. The purple curve in e shows the presence of new diffraction peaks. g, h Evolutions of the lattice parameter a and the cell voltage with the lithium content in the structure of LMO (g) and EI-LMO (h), respectively. The black circles in (g and h) and red squares in (g) represent the Li1-xMn2O4 and λ-MnO2 phases, respectively.
