Solid Bielectrolyte Cells for Thermodynamic Measurements

Abstract

Galvanic cells utilizing two mixed conducting solid electrolytes in intimate contact with each other, and in which transport occurs by a common ion, have been analyzed. The voltage of such cells depends on the nonmetal (or metal) chemical potential at the interface between the electrolytes. A method for calculating the chemical potential at the interface from steady‐state transference conditions has been described and example calculations for a bielectrolyte cell have been presented. Voltages less than the thermodynamic value must be expected for bielectrolyte cells when one or both electrolytes exhibit and their partial electronic conductivities are comparable. The bielectrolyte cell arrangement seems to offer no outstanding advantages for thermodynamic measurements over a single electrolyte cell with a properly chosen reference electrode.