In summary, we developed an experimental technique, called Flow Electrochemical Atomic Force Microscopy, which allows the in-situ characterization of Li 2 O 2 morphology during its formation and electrochemical oxidation. This experimental setup does not require placing the AFM inside a glove box, representing an advantage against the EC-AFM used in the previous works aforementioned. The system was tested with a model cell of the LOB in which a HOPG was used as cathode and a 0.5 M solution of LiTFSI in DMSO O 2 -saturated as electrolyte. This cell allows us to visualise the oxidation process in thin Li 2 O 2 deposits, which begins in the thinnest areas of the deposit and then proceeds laterally in the thickest areas. Additionally, it was observed the formation of larger nanoparticles with elongated and spherical globular shape, attributed to the solution mechanism of Li 2 O 2 formation. The oxidation of these nanoparticles, on the other hand,