Figure 1.

Mn chemical phases and their distribution within LRM-NMC particles cycled at C/10 rate between 4.9 and 2.5 V. Panels a to d: Representative 2D XANES chemical maps of Mn, as a function of cycling. The color maps were determined by fitting each of the single pixel XANES spectra (30 nm resolution; ∼10⁶ per field of view, created from energy stacks of images³⁶) to the reference spectra for the 200×-cycled or pristine electrodes, assigned to green or red, respectively. The scale bar shown in panel a is 10 μm. The X-ray near-edge spectra and magnified plots of the two end components, the pristine and 200×-cycled samples, are shown in panels e and f, respectively, as well as the corresponding data for a few known Mn-based compounds. The edge energies of the spectra are defined as the energies at half-height of the white-line peak.