Finally, the Li1s spectra do not show any peak shifts or broadening up to 500 K annealing, Hence, up to that point, the electronic state of the Li species, which based on its BE of 56.4 eV is strongly positively charged (Li + ), is stable. Annealing to 650 K leads to a broadening of the Li1s peak at the lower-BE side. After annealing to 700 K, which goes along with a significant intensity loss, only a narrow peak with its maximum at about 55.9 eV remains. This behavior, which closely resembles that in the Li1s monolayer spectra, can be explained in a similar way, namely by (reactive) desorption of most of the Li-containing BMP-TFSI decomposition products upon annealing to 650 K and 700 K, leaving mostly adsorbed or dissolved Li 0 species on the graphite surface.