2D X-ray Fluorescence Imaging as a Probe for Charge State Distribution of Manganese in Aged MnHCF-Based Electrodes

The contrast images of the different states of charge of manganese in a manganese hexacyanoferrate (MnHCF) cathode material are achieved with the synchrotron-based two-dimensional (2D) X-ray fluorescence (XRF) technique. XRF, otherwise known to be unable to differentiate between the various oxidation states of the elements, in this case becomes sensitive through the modification of the initial excitation energy due to the advantage of the particularly large energy gap between the K-edge energies of manganese species in the different oxidation states of MnHCF.