Fig. . Li NMR spectra before and after lithiation. a Li NMR spectrum recorded for the "collapsed" oxysulphide phase (Batch 1) and b after its electrochemical lithiation (i.e. after discharge down to 0.5 V (vs. Li/Li + ) corresponding to the intercalation of 1.75 equiv. of Li; see Fig. ) and c after chemical lithiation (i.e. after addition of 1.5 equiv. n-BuLi; see Fig. ). Each spectrum was deconvoluted (black line: observed, red line: fit) into Gaussian or Lorentzian peaks and their hyperfine shifts were interpreted in terms of the Li local structure as well as the Mn 2+ /Mn 3+ ratio. Sidebands of the peak at 0 ppm (due to diamagnetic impurities) are labelled with a *. See Fig. for their whole spectra. d Three possible local environment around Li. Black thick lines highlight connectivity between Li and four nearby Mn 2+/3+ cations. Mn 2+/3+ cations are either sandwiched symmetrically by S 2-anions at apexes of tetrahedra, or asymmetrically by S 2-apexes and S2 dimers. In the latter case, charge transfer from S2 dimers to Mn leads to stronger Mn-S- Li interactions.