On the controlled electrochemical preparation of R4N+ graphite intercalation compounds and their host structural deformation effects

We present electrochemical studies of tetraalkylammonium (R ₄N⁺) reduction chemistry at Highly Orientated Pyrolytic Graphite (HOPG) and glassy carbon (GC) electrodes. We show that by electrochemically controlled intercalation and formation of a graphite intercalation complex (GIC) into layered HOPG, the irreversible reduction of the tetraalkylammonium cation can be prevented and subsequent de-intercalation of the GIC via the use of potentiostatic control is achievable. R₄N ⁺ cations with varying alkyl chain lengths (methyl, ethyl and butyl) have been shown to exhibit excellent charge recovery effects during charge/discharge studies. Finally the effects of electrode expansion on the degree of recovered charge have been investigated and the observed effects of R₄N⁺ intercalation on the graphite cathode have been probed by scanning electron microscopy (SEM) and X-ray diffraction (XRD).