Soft X-ray Absorption Spectroscopic Investigation of Li(Ni_0.8Co_0.1Mn_0.1)O₂ Cathode Materials

Herein, we report the soft X-ray absorption spectroscopic investigation for Li(Ni_0.8Co_0.1Mn_0.1)O₂ cathode material during charging and discharging. These measurements were carried out at the Mn L-, Co L-, and Ni L-edges during various stages of charging and discharging. Both the Mn and Co L-edge spectroscopic measurements reflect the invariance in the oxidation states of Mn and Co ions. The Ni L-edge measurements show the modification of the oxidation state of Ni ions during the charging and discharging process. These studies show that e states are affected dominantly in the case of Ni ions during the charging and discharging process. The O K-edge measurements reflect modulation of metal-oxygen hybridization as envisaged from the area-ratio variation of spectral features corresponding to t and e states.