Fig. 3: In situ HE-XRD characterization.

a, c Enlarged in operando synchrotron XRD contour plots and corresponding charging/discharging curves of pristine SC81 (a) and SC81-air (c) with crystal planes denotations. The batteries underwent two charge-discharge cycles at a specific current of 0.2 C (40 mA g−1) and a temperature of 25 ± 1 °C within the voltage ranges of 2.7–4.5 V. b, d The selected (003) reflection of pristine SC81 (b) and SC81-air (d) at different voltages during the first cycle. The arrow lines indicate the reaction direction and “active” phase evolution pathway.