“…21 Although ceramic electrolytes have certain advantages (electrochemical stability, Li + conductivity, and mechanical strength), their brittle nature, high electrolyte−electrode interfacial resistance, and high processing costs limit their commercial applications. 22 SPEs are a combination of polymers, e.g., poly(ethylene oxide) (PEO), polyvinylidene fluoride (PVDF), poly(vinyl alcohol) (PVA), polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP), poly(methyl methacrylate) (PMMA), poly(vinylpyrrolidone) (PVP), etc., and different Li-salts (LiTFSI, LiFSI, LiClO 4 ). 23,24 SPEs generally exhibit flexibility and good interfacial contact with the electrodes and can accommodate the volumetric expansion of electrodes during the charge−discharge cycle.…”