In this same region, Sc doping is found to maintain the high-voltage plateau, but with lower capacity. These differences can be more clearly seen from the different intensities of the oxidation peaks in the corresponding dQ/dV curves above 4.0 V (see Figure ), where O3-NaNMO shows the sharpest and highest intensity peak. The Scdoped material also shows a sharp oxidation feature but with lower intensity, and the Mg-doped material shows the lowest intensity and broadest feature in this region.