Figures show the AFM images and topographic profiles of the HOPG surface taken during the CV shown in Figure . At the OCP (Figures and) it can be observed the characteristic steps and terraces of the HOPG. After the cathodic scan, at 2.0 V, a deposit of Li 2 O 2 nanoparticles (~3 nm height) covers uniformly the HOPG surface (Figure ). After the anodic scan, at 4.8 V, small holes appear in the deposit, revealing the oxidation of Li 2 O 2 , while the rest of the deposits remain stable (Figure ).