Understanding energy storage and charge transport mechanisms of halide-based cathode materials via XAS

We recently proposed amorphous Fe-based and V-based high ionic conductivity halide cathode materials, which can cycle at room temperature without the additional catholyte. Both halide cathode materials present multi-electron transfer reactions for lithium storage, as well as rapid ionic transport characteristics. To investigate redox reaction mechanism of Fe-based and V-based halide cathode materials, X-ray Absorption Spectroscopy (XAS) experiments are significant to investigate the changes in the valence states and the evolution of local coordination environment of the transition metal in amorphous materials. X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) spectra will confirm the valence state changes of Fe/V species and illustrate how Fe/V atoms coordinate with halide atoms. These results will provide an in-depth understanding of the synthesis and properties of halide cathode materials and may stimulate research in related fields.