To analyze the chemical stability of KSC we derived possible decomposition products as described in the experimental section. In Figure Note again that in the presented grand canonical picture, we consider a Cl reservoir represented by the LiCl anode which accounts for the stoichiometrically missing Cl in the chemical equation. Furthermore, due to the mentioned inaccuracies of the above-presented convex hull analysis, it might well be possible that in addition to the just presented reactions some other species like Sn𝐶𝑙 2 or different K-Sn alloys may be involved in the reactions taking place during cycling. In order to analyze the potentially stable structures in more detail as a function of the electrode potential, ternary phase diagrams are displayed in Figures where green and red data points represent Ehull = 0 and Ehull > 0, respectively. Of the highlighted data points in Figure corresponding to K2SnClx only K2SnCl6 is determined to be stable whereas the reduced compounds (5 ≤ 𝑥 < 6) display Ehull values somewhat larger than 0 meV/atom.