Abstract: To investigate the formation of a solid electrolyte interface (SEI) on the Li V O electrode surface in the 11x 3 8 thermodynamic stability range of the organic electrolyte, we applied scanning photoelectron microscopy (SPEM) to a pristine electrode and to an electrode after ten cycles. The F K-edge absorption spectrum of the cycled electrode showed that LiF forms on the electrode surface during the lithium insertion