Fig. 2: Structural characterizations of amorphous Na3PS4−xOx (x = 0, 0.15, 0.30, and 0.60) SEs.

Spectra from a Synchrotron X-ray diffraction, b Raman, c 31P NMR, d Structural units and their relative mole percentage, e Fourier transform-infrared spectra (FTIR), and f O 1 s X-ray photoelectron (XPS).