Application of the general transport theory to solid state galvanic cells

Application of the general transport theory to solid state galvanic cells Let us once again consider, as a specific example, the cell Pt/FeO, Fe3 04/Zr02(-1-Me0)/Fe304, Fe203/Pt 

This cell, which was discussed previously, is shown in Fig. 9-5. We shall examine how the chemical, electrical (Galvani-), and electrochemical potentials (/if, r vary across this cell. 

The knowledge which we gain can then be directly applied to other cells. According to the Gibbs phase rule, the chemical potentials of all particles in the two-phase electrode compartments are constant. The two-phase mixtures are electronic conductors, and so the transport number of the electronic charge carriers is unity. Therefore, the electrical and electrochemical potentials of all partners in the electrode compartments are constant. 

According to eq. (5-13), the following transport equations apply within the solid electrolyte  

The transport number t i of the oxygen ions in the electrolyte is assumed to be unity. The transport numbers of the cations are negligible for this material. Furthermore, at open circuit the total current density / = 2,- Fj in the electrolyte must vanish. From these two conditions 

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