Record Details
Field | Value |
---|---|
Title | The discharge and recovery of the vanadium pentoxide electrode |
Names |
Watson, Naola VanOrden
(creator) Scott, Allen B. (advisor) |
Date Issued | 1963-08-06 (iso8601) |
Note | Graduation date: 1964 |
Abstract | Vanadium pentoxide electrodes were prepared by melting the powdered oxide around a platinum foil in a pyrex tube. The electrode was discharged, and the discharge product was studied, but not identified, by means of chemical and x-ray diffraction analysis. A study was made of the relationship between the electrode potential and the pH of the electrolyte solution. It was found that the number of electrons per hydrogen ion in the discharge reaction was unity at a pH between two and five. The electrode potential during discharge was plotted against the time of discharge and the resulting curves were compared with curves calculated upon a theory based upon diffusion of the reduction product into the solid electrode. It was found that the diffusion equation predicted the shape of the experimental curves. The diffusion coefficient for the discharge product was calculated from experimental discharge curves and the equations for diffusion. A diffusion coefficient of 3 x 10⁻¹⁸ cm² per sec was obtained. A mechanism for the discharge and recovery of the vanadium pentoxide electrode is proposed. It is suggested that the discharge consists of the reduction of the vanadium pentoxide to a lower oxy-hydroxide accompanied by an effective diffusion of the oxy-hydroxide by the migration of protons and electrons into the body of the electrode. The electrode potential is dependent upon the composition of the solid solution formed between the pentoxide and the oxy-hydroxide on the surface of the electrode. The recovery, after the discharge current is removed, consists of the further diffusion of the oxy-hydroxide away from the surface and the resulting increase in the activity of the pentoxide on the surface, until the composition is uniform throughout the electrode. |
Genre | Thesis/Dissertation |
Topic | Electrodes |
Identifier | http://hdl.handle.net/1957/49037 |