Performing in-operando HERFD-XANES studies of the LiNi0.90Mn0.05Co0.05O2 cathode material to investigate the role of oxygen-vacancies on cap

The LiNi0.90Mn0.05Co0.05O2 (NMC900505) cathode material can be synthesised under different concentrations of O2, where lower O2 concentrations are likely to introduce higher oxygen-vacancy concentrations in the resulting phases. Here we will investigate samples synthesised under 3 different O2 concentrations and probe the effect that these oxygen-vacancies have on the electronic structure of the Ni, Mn and Co 3d transition metal ions during the 1st charging and discharging cycle. We will use HERFD-XANES measurements taken during operation of the cathode material in order to compare the changes seen for each of the 3 samples.