Electrochemical intercalation of bromine into graphite in an aqueous electrolyte solution

By electrochemical oxidation of a graphite sheet in an aqueous solution of potassium bromide, the intercalation of bromine was observed. It was confirmed by the measurements of weight increase of about 10%, decrease in relative electrical resistivity down to 0.69, and enlargement of average interlayer spacing. On the graphite sheet pre-electrolyzed in KBr solution, the chronopotentiogram in K2SO4 aqueous solution showed some plateaux corresponding to the reduction of graphite intercalation compounds with bromine. The longest time on a plateau was observed on the graphite sheet pre-electrolyzed in a potential region of bromine gas evolution, where the most pronounced decrease in electrical resistivity of graphite sheet was detected.