Preparation of air-stable and highly conductive potassium-intercalated graphite sheet

Abstract Potassium–graphite intercalation compounds with chemical compositions of KC 84 , KC 48 , KC 36 and KC 8 were prepared from PGS graphite sheet and then treated with 6 M-HCl aqueous solution. After washing with water and drying under open air, chemical composition, stage structure and electrical conductivity of the resulting air-stable compounds were determined. It was found that about 40% of potassium in the starting potassium–graphite intercalation compounds remained in the matrix after treated with 6 M-HCl aqueous solution for KC 84 , KC 48 and KC 36 , while 15% for KC 8 . The room temperature electrical conductivity of an air-stable compound, containing potassium of 0.008 in molar ratio of potassium to carbon, was determined to be 1.3×10 5  Scm −1 . This is comparable to that of iron (1.0×10 5  Scm −1 ) and about 1/3 of that of aluminum (3.6×10 5  Scm −1 ).