Finally, the Li1s peak, which is located at 56.7 eV upon Li deposition, remains about constant in BE upon annealing to 400 K and 450 K, while the intensity seems to increase slightly. Most simply, this increase in intensity is due to the desorption of volatile F-and N-containing species discussed above. The considerable intensity increase upon annealing to 500 K is at least partly due to the generally higher intensity in this measurement (see above). In addition, the peak seems to broaden to lower BEs. Annealing to 650 K, finally, leads to the formation of an asymmetric peak shape with its maximum at lower BE, at 55.5 eV, together with a significant intensity loss. This peak, which would be compatible with a metallic Li 0 component, seems to form already during annealing to 500 K, where it leads to the peak broadening. Both the peak shift and the loss in intensity can be explained by decomposition of Li containing compounds, leaving Li 0 species in the surface region and below. The loss of Li intensity is then due to Li 0 dissolution into deeper regions, where it is less or no more visible by XPS.