Fig. 5

In situ XRD characterization of Na_0.27MnO₂. Two CV scans were conducted between −1.25 V and 1.25 V at a scan rate of 0.75 mV s⁻¹, showing the changes of d-spacing for (001) basal diffraction plane and (020) Bragg diffraction plane and the contour plot peak variation of (001) plane during the charging (black) and discharging (blue) processes