fig8

Figure 8. (A) In situ XRD patterns of PNCNFs during the discharge/charge process. This figure is quoted with permission from Wang et al.^[92]. (B) In situ XRD patterns of Bi@N-CNCs during the first discharge/charge process; (C) Schematics of the phase change during the first discharge process. This figure is quoted with permission from Hu et al.^[124].