Lithium-ion batteries (LIBs) have become the dominant power source for portable electronics and automotive applications. The depletion of lithium resources worldwide necessitates the exploration of alternative electroactive species that can be extracted from cheap and abundant raw materials to establish a sustainable and economically viable new chain in energy storage. Therefore, there has been a growing interest in post-Li batteries based on Na + , K + , Ca , and Zn 2+ cation shuttles as viable alternatives to LIBs. However, developing alternative battery systems with long cycle life and low cost, without sacrificing energy density, remains a challenge. Recently, there has been growing interest in rechargeable batteries based on an anion shuttle, such as chloride or fluoride batteries that operate at room temperature . CIBs show significant potential as future power sources due to their high theoretical energy density (~2500 Wh L -1 ). Despite their larger ionic radius compared to Li + , Mg + , O 2-and F -, Cl -ions offer higher ionic mobility in the electrolyte, which could lead to faster reaction kinetics. A typical CIB is composed of a metal chloride electrode that supplies chloride ions, an electrolyte for carrying the Cl -ions, and a counter electrode with a low reduction potential. In literature, several materials have been studied at the cathode side, however, stability issues arising from the dissolution of these materials in the applied organic electrolytes were often encountered, which precluded their application in chloride ion batteries. The development of a stable electrode material, which exhibits lower volume expansion than existing metal chlorides, remains an unresolved challenge. Metal oxychlorides such as FeOCl, BiOCl, and VOCl have recently been explored as cathode materials, offering improved electrochemical performance and stability over metal chloride-based cathodes. Furthermore, Sb4O5Cl2 and a Sb4O5Cl2/graphene aerogel composite (Sb4O5Cl2-GAG) were employed as anodes for aqueous CIBs and cathodes for non-aqueous CIBs, respectively. The ability of metal oxychlorides to function effectively as active material in both anodes and cathodes, depending on the working conditions, underscores their adaptability in CIB technology. Perovskites with a chemical formula of ABX3 possess valuable properties for batteries and supercapacitors, which has led to their use as electrodes and electrolytes. As an example, the promising potential of perovskite halides like CsSnCl3 and CsSn0.9In0.067Cl3 as chloride ion conductors were demonstrated. Despite this, there is a surprising lack of exploration into their specific application as electrodes within CIBs. This highlights the clear need for focused research into developing novel perovskite-based electrodes specifically designed for CIBs. In this study, we investigate KSC, as a new electrode material for non-aqueous chloride ion batteries. K2SnCl6 materials are synthesized by a one-pot mechanochemical ball-milling route which is, in comparison to high-temperature sintering techniques and organic solvent-assisted processes, a more effective way. The electrochemical performance of the anti-fluorite structured K2SnCl6 is investigated in non-aqueous electrolytes with lithium metal as anode. Furthermore, to understand the structural changes during cycling and the electrochemical reaction mechanism, ex-situ XRD and XPS measurements are conducted. The experimental insights were complemented by theoretical investigations within the framework of periodic density functional theory (DFT) where potential pathways for the electrode reaction were examined and based on a theoretical stability analysis a number of potential decomposition reactions were derived. The refined XRD pattern and crystal structure of as-synthesized KSC (dried) are displayed in Figures and respectively. Rietveld refinement of the KSC powder diffraction data using GSAS II revealed a cubic unit cell with space group Fm-3m (#225-1). The lattice parameters were refined to be a = b = c = 10.01390 Å with all angles α = β = γ = 90°. The unit cell volume was determined to be 1004.1757 Å 3 . A thermogravimetric analysis (TGA) curve was used to compare the weight loss of the as-synthesized and dried samples, the results are shown in Figure . These measurements confirmed the removal of small amounts of residual water in the temperature range between 50 and 250 °C for both samples (cf. inset in Figure ), with a larger loss for the as-synthesized sample (1.2 %) compared to the dried one (0.5 %), indicating a reduction of the water content in the dried sample. More structural features are revealed by the Raman spectra in Figure , in which three distinct bands are observed, each corresponding to specific vibrational modes. First, the F2g mode, associated with the in-plane bending of Sn-Cl-Sn bonds, was observed at approximately 170 cm -1 . The Eg mode at around 241 cm -1 is related to the asymmetric stretching of the Sn-Cl bonds. Finally, the A1g mode, corresponding to the symmetric stretching of the Sn-Cl bonds, is observed at ~ 322 cm -1 . The results of XPS measurements from KSC can be found in Figure in the Supporting Information. In brief, the detail spectra show in the K 2p, Sn 3d and Cl 2p regions single doublets (K 2p3/2, Sn 3d5/2 and Cl 2p3/2 peaks at 294.0, 488.0 and 199.4 eV, respectively) which can be assigned to KSC. Furthermore, energy-dispersive X-ray spectroscopy (EDX) mapping showed a homogenous distribution of the elements (Cl, K, and Sn) throughout the material. In addition, quantitative evaluation of the EDX spectrum (see Figure in the Supporting Information) corroborated the expected atomic ratio K, Sn and Cl, viz., 2:1:6 validates the composition of K2SnCl6 ₆ in the material studied. The transmission electron microscopy (TEM) analysis is employed to analyze the morphology and crystal structure of KSC on a nanoscopic length scale (Figure ). The selected area electron diffraction (SAED) ring pattern (Figure ) is indicative of a polycrystalline nature of the material. The SAED rings were indexed to the (311), (400), (420), and (440) crystal planes of the K2SnCl6 crystal structure, corresponding to d-spacings of 0.31, 0.25, 0.22, and 0.18 nm, respectively, further corroborating the XRD findings. High-resolution TEM image (Figure ) further confirms the crystalline nature of the material, with clearly visible lattice fringes. The spacing of the observed fringes was measured to be 0.31-0.32 nm, corresponding to the lattice spacing of the (311) set of planes of the K2SnCl6 crystal structure (ICSD collection code 1668). EDX analysis in scanning transmission electron microscopy (STEM) mode (Figure ) reveals a homogenous distribution of K, Sn, and Cl elements throughout the as-synthesized powder. The structure is polycrystalline, the composition is as expected for KSC could potentially impart the material with enhanced properties for a variety of energy storage-based applications.