ELECTROCHEMICAL PROPERTIES OF NICL2-INTERCALATED AND REDUCED-NICL2-INTERCALATED GRAPHITE

The feasibility of modifying graphite, by intercalation, to reduce galvanic reactions in carbon fiber reinforced metal matrix composites is investigated. A nickel chloride intercalation ComPound (NiCl2-GIC) and a reduced nickel chloride intercalation compound were prepared (r-NiCl2-GIC), and their electrochemical properties studied in deaerated 0.1 N NaCl. The open-circuit potential of NiCl2-GIC is about 0.500 V more positive than that of natural graphite while that of r-NiCl2-GIC is about 700 V more negative than that of natural graphite. In the latter case, the potential difference relative to aluminum is reduced by about 50%. Distinct changes in the cathodic behavior of graphite upon intercalation and reduction are also observed. Results are discussed in terms of the effects of these changes on galvanic interactions with aluminum alloy Al 6061-T6.