The importance to study separately the composition and properties of the solid electrolyte interphase (SEI) on basal and cross-section planes of graphite particles is demonstrated. The lateral distribution of SEI forming compounds at submicron resolution is presented for the first time. It was found that Li and F are the main constituents of the SEI cross-section. The SEI on the solution-side surface of the basal plane contains much more organic materials than that of the cross-section one. The SEI on the HOPG can be described as non-homogeneous. The SEI cross-section is dominated by Li and F, with one to several dozen micron-sized regions where Li and F are almost absent. The distribution of C2H (and other C x H y -based fragments), O, C2H3O2 (59), and C2H3O (43), shows full coverage and is fairly homogeneous. The true lateral size of the microphases is about 1μm. TOF SIMS measurements provide direct evidence for the existence of polymers in the basal SEI.