Synthesis, Short-Range Order Structure, and Thermal Properties of Mixed Oxy-sulfide Nitride (MOSN) Glasses

Nitrogen doping has been shown to greatly improve the stability of solid electrolyte (SE) materials at the anode and cathode interfaces in all solid-state batteries (ASSBs) as widely demonstrated by the LiPON family of compositions. In an effort to expand the use of nitrogen in SEs, in this study, mixed oxy-sulfide nitride (MOSN) glasses were prepared by direct ammonolysis of the sodium oxy-sulfide phosphate Na₄P₂S_7-O (NaPSO) glass series to understand the combined effects that oxygen and sulfur have on the incorporation of nitrogen. The short-range order (SRO) structures of the Na₄P₂S_(7-ON (NaPSON) glasses were investigated with Raman and infrared (IR) spectroscopies to understand the effect that nitrogen has in the glass structure. The N content of the glasses was quantified by elemental analysis and confirmed through weight change measurements. By combining this information, it was further possible to determine the anion exchange ratio, z, for the N substitution of O and S as a function of the base NaPSO glass chemistry, x. The composition-dependent glass transition temperature, T_g(x), measured with differential scanning calorimetry (DSC), was found to correlate well with the measured N/P ratio, y, in the NaPSON glasses.