Rotating disc studies of the vitreous carbon—sodium polysulphide interphase

Steady-state current-potential measurements have been made at the vitreous carbon-sodium polysulphide (liquid) interphase at temperatures of 305 and 350°C. Molten Na₂S₃ and Na₂S₅ were employed; the results obtained were not very dependent on melt composition.Evidence was found for at least three electrode processes: (a) near the equilibrium potential a diffusion-controlled redox reaction occurs; (b) at cathodic potentials a diffusion-limited reaction proceeds at an electrode covered by a sodium polysulphide film; and (c) at anodic potentials globules of sulphur are produced on the electrode surface.