Fig. 6. (a) The STEM images and (b) corresponding line profiles of the NCT electrode at pristine (left), fully charged (middle) and fully discharged (right) stages. (c) In operando XRD patterns measured at 10 mA g⁻¹ and phase evolution during cycling. (d) Density difference electron density maps for different states produced by Fourier transforms. (e) Schematic plot of reversible TM migration upon cycling. (a)–(e) are reprinted with permission from ref. 105. Copyright 2019 Wiley.