Fig. 2. Operando XRD peak behaviour of each species rising and falling during the Li doping (blue) and removal (red) in MAPbBr₃. (Wavelength λ = 0.9918 Å, 12.5 keV) Blue data corresponds to peak changes during Li insertion and red data to Li removal. Peaks proceed from low to high colour intensity as indicated by arrow. Peaks correspond to: (a and b) (020) and (101) MAPbBr₃ (cubic space group Pm3̄m). The two orientations overlap and resolution is not sufficient to distinguish. (c and d) (111) Pb⁽⁰⁾ (cubic space group Fm3̄m). (e and f) (001) LiBr (hexagonal space group P6₃mc) (g and h) Behaviour of the (001) reflection of PbBr₂ during the first charge cycle (bottom red) and second lithiation (top blue) cycle. (orthorhombic space group Pnma.) The corresponding cell potential and doping concentrations for each peak are provided in colour bars at the top and bottom of the figure.