Rietveld analysis can be used to analyze the details of the structural changes occurring on charging RP-type phases within FIBs. From this analysis, weight fractions as well as lattice parameters of the individual phases can be extracted. The results of this analysis (performed on the patterns shown in Figure ) can provide a more detailed understanding of the charging process. From a close inspection of the shape of the reflections of the RP-type phases, it becomes clear that it is not possible to refine the pattern of the low-fluorine content phases by a single RP-type phase, and multiple RP-type phases were found to be required to obtain an acceptable fit of the diffraction pattern (see Figure 2). On increased charging, we find changes of the different modifications of RP-type phases present along with changes of their phase fractions (see Figure ). Partly, the lattice parameters and cell volumes of the individual phases can be slightly affected dependent on the detailed state of charge.