For the F1s region, we find a significant loss in intensity of the FTFSI+Li peak (cyan) upon annealing to 500 K, and it completely disappeared upon annealing to 650 K. In this latter annealing step, also the low BE FTFSI,dec-1 peak, which in previous steps had grown due to the decomposition of the molecular species represented by the FTFSI+Li peak, lost much of its intensity. Apparently, the underlying binary compound, most likely adsorbed LiF-like species, started to (reactively) desorb under these conditions.