In the S2p region, Li deposition leads to an additional peak at about 161.6 eV (STFSI,dec-2, yellow), which had previously been assigned to Li2S-like species. This assignment will be discussed in more detail in section 3.2.2. Furthermore, the broadening of the TFSI-related peak to lower BEs points to the formation of another component with slightly lower BE. Deconvolution results in a peak centered at 168.0 eV (STFSI,dec-1, blue-yellow), in addition to the TFSI-related STFSI+Li peak at 169.5 eV. Upon annealing to 400 K, 450 K and 500 K, we find little change in the total S2p intensity, resembling the behavior of the N1s core levels. Also the different components do not change significantly, neither in intensity nor in BE. Only upon annealing to 650 K we find a drastic decrease of the high-BE peaks (STFSI+Li and STFSI,dec-1), accompanied by a significant increase of the low-BE STFSI,dec-2 peak. Obviously, under these conditions a large fraction of the molecular species in the high-BE peaks react to the species responsible for the low-BE peak. Furthermore, based on the significant loss in total intensity, also desorption of species volatile under these conditions takes place as competing process. Annealing to 700 K finally results in the complete disappearance of the high-BE peak, while the low-BE peak seems to be stable. The apparent increase in intensity of the STFSI,dec-1 peak (yellow) at this point may be due to desorption of S-free covering species, as its intensity increase is more than the transfer from the former high-BE peak could account for.