Electrochemical synthesis and characterization of formic acid graphite intercalation compound

A formic acid-graphite intercalation compound (HCOOH-GIC) has been successfully synthesized by an electrochemical process whereby formic acid solution serves as both the electrolyte and the intercalate source. Stage structures of 3, 4 and 5 have been revealed by both X-ray diffraction and Raman spectroscopy. Formation of HCOOH-GIC was achieved by controlling the apparent anodic current density in the range of 5-10 mA cm(-2) and the reaction duration for 5 to 10 hours. The synthesized compounds can be exfoliated by rapid heating to a relatively low temperature (similar to 400 degrees C). Their expansion volume reaches 150 to 300 ml g(-1) with the specific surface area of 20 to 50 m(2) g(-1). Since no sulfur is involved in this process, formic acid-GIC can produce flexible graphite for elevated temperature sealing without any corrosive elements. Electrochemical intercalation of other organic acids into graphite has also been investigated in this work. (C) 1997 Elsevier Science Ltd.