Kinetics of metal-oxygen reaction by solid oxide electrolyte cells

Chronopotentiometric curves, generated by galvanostatic single steps, applied to solid oxide electrolyte cells, have been analysed on the basis of a dimensionless equation derived on the assumption that a scale of oxide grows at one of the electrode-electrolyte interfaces. This process is rate limiting for developing the charge transfer-diffusion overvoltage, and Wagner's theory on tarnishing under retarding electric field conditions, has been assumed for treating the kinetics of the growing scale. At constant temperature, the oxidation rate and oxidation rate constant have been measured as a function of the oxygen partial pressure in the range of pressures near the equilibrium pressure of the metal-oxide system.