Structure and electrical properties of a new thio-phosphorus oxynitride glass electrolyte

• A new sulfur and nitrogen containing lithium phosphate glass has been obtained.
• Both N and S substitute for oxygen positions in the Li-phosphate glass.
• The conductivity is 1.5 orders of magnitude higher than that of the parent glass.
• This new Li-P-O-S-N is highly stable in air due to the presence of nitrogen.

For the first time, a thio-phosphorus oxynitride glass containing nitrogen and sulfur, LiPOSN, has been prepared by a melting process in two steps and its manipulation is possible in air without any decomposition. The anionic substitution of oxygen by sulfur and nitrogen in the phosphate glass structure has been confirmed by 1D 31P solid state NMR and XPS. The 2D 31P DQ-SQ experiment indicates that S bearing phosphate groups are integrated into the global phosphate network and do not form clusters. Through the study of the properties of this glass, it was verified a decrease of the glass transition temperature, due to the depolymerization of the phosphate network when lithium sulfide is introduced into the oxynitride glass, along with a pronounced increase of the ionic conductivity, that suggest that this glass can be considered as a new highly conductive and corrosion resistant glass electrolyte.