ABSTRACT
Figure 8 Detailed XPS spectrum (Cls region) for a carbon electrode passi vated in KF • 2HF by 20 scans at v = 0.4 V s-1 in the potential range 0 .5-9 .5 V; t = 85°C. C(l) and C(2) correspond to two kinds of C -0 bonds, according to Ref. 36. (Courtesy of H. Groult, C.N.R.S., Paris.)
evaluated to be about 1 |xm. The external layers constitute a thin perfluorinated insulating film, a few angstroms thick, through which the current flows by tunnel effect. This hypothesis of a nonhomogeneous film of CFX has been proposed by other authors studying the anode overvoltage in fluorine cells [21].
