The potential change from 0.45 to 0.55 V proceeds over a capacity range of 20-30 mAh g -1 . This corresponds to a first oxidation of the transition metal-ions of the RPtype compound from fluoride-ion incorporation. The process only induces moderate changes of the lattice parameters (see later in this section), and is accompanied by broadening and asymmetry of the reflections (in special those with l≠0, e.g., shoulders appearing on the (103) reflection), see Figure . This likely originates from the lattice distortions occurring on inserting F -in the interstitial anion sites , and inhomogeneous F -distribution in the active material particles.