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

Potassium–graphite intercalation compounds with chemical compositions of KC84, KC48, KC36 and KC8 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 KC84, KC48 and KC36, while 15% for KC8. 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 1.3×105 Scm−1. This is comparable to that of iron (1.0×105 Scm−1) and about 1/3 of that of aluminum (3.6×105 Scm−1).