Fig. 2

Structural evolution of NaCrS2 during sodium deintercalation and intercalation. a In situ XRD during the initial cycle for NaCrS2, corresponding voltage curve is shown on the right. The 2θ is converted to the corresponding angle for λ = 1.54 Å (Cu-Kα) from the real wavelength λ = 0.7747 Å used for synchrotron XRD experiments. Evolution of lattice parameters b a/b and c c calculated from the in situ XRD during the first charge/discharge process