Corrosion of graphite intercalation compounds

✍ Scribed by F. Beck; H. Krohn; E. Zimmer

• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 496 KB
• Volume: 31
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(86)80092-5

✦ Synopsis

HzS04 and 1-12 M HCIO, has been investigated withcharged graphite (80 wt %)/polypropylene (20 wt %) composite electrodes "CPP". An electrochemical mechanism is found for the process. The anodic reaction is the slow oxidation of the graphite surface to C-COOH, CO and CO*. This has been studied by anodic current voltage measurements in dilute acids. Cathodic reaction is reversible deintercalation of GIC. The rate is determined by the anodic process, while corrosion potential is near the intercalation potential. Opencircuit potential/time curves with charged CPP electrodes in various electrolytes lead to life times in excess of loo0 h, corresponding to average corrosion rates below 1 fi cm-' for c~~so. 2 6 M and CHCQ > 4 M. This agrees with the corrected anodic current voltage curve. The corrosion rates are appreciably enhanced in the case of high surface concentrations of anions in GIC (rapidly charged electrodes) and of localized cell action in contact with uncharged graphite.