Stratigraphic analysis of intercalated graphite electrodes in aqueous inorganic acid solutions

Abstract A detailed stratigraphic investigation of the intercalation mechanism when graphite electrodes are immersed inside diluted perchloric (HClO 4 ) and sulfuric (H 2 SO electrolytes is obtained by comparing results crystals simply in same acid solutions. By combining time-of-flight secondary ion mass spectrometry (ToF-SIMS) in-situ atomic force microscopy (AFM), we provide a picture chemical species involved reaction. The depth intensity profile signals along electrode crystal clearly shows more complex for process, where local morphology basal plane plays crucial role. Solvated anions mostly located within first tens nanometers graphite, but also diffuse buried layers hundreds nanometers, latter process aided presence mesoscopic defects. Residual material from electrolyte solution was found localized well-defined circular spots, which represent preferential interaction areas. Interestingly, blister-like micro-structures similar to those observed on highly oriented pyrolytic (HOPG) surface were layers, confirming equivalence condition underneath layers.