Spectra recorded upon RT deposition of a thick multilayer film (10 ML) of BMP-TFSI, followed by post-deposition of Li (3.6 ML) at RT and finally stepwise annealing of that surface up to 700 K, are presented in Figure . Since spectra recorded upon RT deposition of BMP-TFSI and increasing post-deposition of Li, up to 3.6 ML, were already presented and discussed previously, the trends during these phases will only be summarized in the following. After RT deposition of BMP-TFSI, the spectra closely resemble those obtained on a monolayer film covered sample, except for a slight up-shift to higher BEs by about 0.6 -0.7 eV and the absence of the pronounced peak in the C1s region at 284.6 eV related to the graphite (0001) substrate (see section 3.1.1). The BEs (see Table ) and the intensity ratios of the different peaks underline that also for thicker films BMP-TFSI adsorbs molecularly intact at RT. The up-shift in BE relative to the monolayer peaks can be attributed to a vacuum level pinning effect, where the core level states of the weakly binding adsorbate are coupled to the vacuum level rather than to the Fermi level of the substrate. Upon Li post-deposition (3.6 ML) and subsequent annealing, the BMP-TFSI related peaks stepwise decay in intensity and additional peaks emerge at lower BEs. Different from reaction with the adsorbed monolayer, there is no general Li-induced shift of the peaks related to the BMP-TFSI bulk. Only for the higher-BE NBMP peak, we find a small up-shift (see below). The absence of a general shift can be rationalized by the absence of the surface dipole generated by the charge transfer from adsorbed Li + to the topmost graphite (0001) layer. Accordingly, the shift of the NBMP+Li peak (red) must be due to a direct chemical interaction between Li and BMP. reference ).