Conductivity studies on LiX–Li2S–Sb2S3–P2S5 (X = LiI or Li3PO4) glassy system

New sulfide glasses in the Li₂S–Sb₂S₃–P₂S₅ system have been prepared by classical quenching technique where glassy domain remains up to 50% molar addition of Li₂S and electrical conductivities have been determined by impedance spectroscopy. Room temperature DC conductivity vs Li₂S content exhibits two regions implying different conductivity mechanisms. The compositions of low lithium content presented low electronic conductivities close to 0.01 μS/cm at room temperature (due to Sb₂S₃ semiconducting properties). The compositions of medium lithium content could result to mixed ionic–electronic conductors with predominant ionic conductivity with a maximum close to 1 μS/cm; Arrhenius behavior is found between 25 °C and T _g for all glasses, but activation energy is found to be somehow above most similar systems. A comparative study with glasses belonging to the other chalcogenide systems has been undertaken and values of the decoupling index are reported, and in order to validate conductivity data, a circuit equivalent circuit was proposed and fitted parameters were calculated with good agreement.