The experimental and theoretical results both demonstrate electrochemical activity of Ni and O redox during the charging process for all investigated materials. The prominent difference between the doped materials is that the 'O bound to Mg' acts as a redox active center, while no activity was found for 'O bound to Sc'. It is important to note that the latter conclusion is a result from the DFT calculations only. Sc XAS measurements were intended to support this finding. However, the low resolution of the measurement data did not provide specific information on the redox activity of 'O bound to Sc'. Overall, it appears that the Sc-doped material and the undoped material previous report. This causes the differences in the voltage profiles of the three materials during charging. Above 4 V, the voltage profile is more sloping in the case of Mg while it is a plateau for the Sc-doped and the undoped materials.