Upon further annealing cycles to 450 K, 500 K and 650 K, the decomposition processes continue, resulting in a further loss of total intensity and in the intensity of the higher BE NBMP+Li (red) and NTFSI+Li/NBMP,dec-1 (cyan-green) peaks. Here it should be kept in mind that the evaporation temperature of neat BMP-TFSI during deposition was 450 K, which resulted in deposition rates of about 0.1 ML min -1 , and temperatures between 450 and 500 K were reported also for second layer desorption of BMP-TFSI from HOPG. Therefore, at temperatures 450 K adsorbed BMP-TFSI can exist only if stabilized by interactions with the graphite surface or, more likely, with coadsorbed Li. The molecular species represented by the NBMP+Li (red) and NTFSI+Li / NBMP,dec-1 (cyan-green) peaks largely disappeared upon annealing to 450 K and were completely absent after annealing to 500 K, forming either volatile compounds or decomposing into smaller solid fragments and finally into the compounds represented by the NTFSI,dec-1 (blue-yellow) and NTFSI,dec-2 (yellow) peaks. Here we assign the NTFSI,dec-2 peak to one or more rather stable binary compounds, most likely LiCN (see discussion in section 3.2.2).