Impact of PVDF Homo and Copolymer on Thiophosphate Solid Electrolyte Characteristics and Comprehensive Bulk‐To‐Surface Characterization

ABSTRACT Solid‐state batteries are widely regarded as the future of electrochemical energy storage; however, their progress is impeded by unresolved chemical and mechanical challenges related to the electrolyte composition preparation. Hybrid electrolytes (HE), produced by combining non‐conductive polymers with thiophosphates, are theoretically anticipated to enhance mechanical strength. The impact of polymer additives on thiophosphate characteristics—such as stability range and ionic conductivity—remains insufficiently understood. In this investigation, a small quantity of PVDF based polymer was manually blended with Li ₆ PS ₅ Cl solid electrolyte at ambient temperature via a dry process. Advanced multi‐scale characterization techniques revealed that the addition of minimal binder preserves high ionic conductivity and maintains a favourable electrochemical stability window, while simultaneously improving material toughness (evidenced by decreased dendrite growth and enhanced interface stability). Nevertheless, intimate mixing of these components induces surface chemical reactions, as demonstrated through comprehensive X‐ray diffraction and X‐ray photoemission spectroscopy.