hydrolytic stability

The oxidative and hydrolytic stability of the precursors Li2S and P2S5 for the synthesis of sulfide solid electrolytes was studied using gravimetric analysis. The study was conducted in air with different water content and dry argon. It was established that the water content in air significantly affects the stability of materials. Li2S and P2S5 are unstable even in air with the water content of 5 ppm. Moreover, it was found that the oxidative-hydrolytic stability of Li2S depends on the presence of impurities.

The hydrolytic and oxidative stability of sulfide solid electrolytes Li7P3S11 and Li3PS4 at different humidity of the gas environment (air and argon) was studied. It was found that increasing the air humidity the oxidation rate of sulfide solid electrolytes also increases. It was shown that the oxidation rate of sulfide solid electrolytes depends on their composition. Thus, Li7P3S11 electrolyte has higher oxidation stability in the humid air compared to Li3PS4. Lithium sulfate is the main oxidation product of sulfide solid electrolytes.