Synthesis, Structural Analysis, and Degradation Behavior of Potassium Tin Chloride as Chloride‐Ion Batteries Conversion Electrode Material

Chloride–ion batteries (CIBs) offer a compelling alternative to conventional battery systems, particularly in applications demanding cost-effectiveness and resource sustainability. However, the development of tailored electrode materials remains a critical bottleneck for CIB advancement. In this study, an untapped class of perovskite-based material, potassium hexachlorostannate (K$_2$SnCl$_6$, denoted as KSC) is synthesized via a facile mechanochemical route for the first time. The prepared KSC is subjected to various characterization techniques to confirm its crystal structure and morphology. Herein, KSC exhibits intriguing electrochemical performance in a non-aqueous CIB configuration, utilizing a lithium metal counter electrode. Furthermore, ex situ X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis, reveal a conversion reaction mechanism involving chloride ion shuttling and provide insights into structural evolution during cycling. Moreover, the density functional theory (DFT) studies support additional degradation products that can potentially limit the performance of these materials as potential battery electrodes in CIBs.