Extended Data Fig. 2: 6Li MAS NMR spectra of the cathodic mixtures and anodic mixtures.

6Li MAS NMR spectra of the cathodic mixtures (a-d) and anodic mixtures (e–g) of Li6PS5Cl in the In|LPSC|LPSC-C and Li-In|LPSC|LPSC-C solid-state batteries respectively. After first charge of the In|LPSC|LPSC-C solid-state cell, formation of LiCl is observed (b). First discharge shows formation at a new resonance frequency corresponding to Li3PS4 (c, d). The solid state cell, which starts from lithiation process (f), results in formation of Li2S, confirmed with the spectrum of the reference Li2S (g).