The electrode resistance of ZrO₂-Y₂O₃(-Bi₂O₃) solid electrolytes with Pt electrodes

The electrode resistance (R_e1) at low over-voltages has been determined for Bi₂O₃ free and Bi₂O₃ doped yttria-stabilized zirconia with sputtered platinum electrodes. The anode and cathode resistances are measured separately and are equal. Bi₂O₃ causes a decrease of the electrode resistance at small overvoltage and with 5×10⁻⁴<P_O2 ≤, 1 atm. The rate determining step for the electrode reaction under the measuring conditions probably is a charge-transfer process in which oxygen adsorbs dissociatively on the bismuth free and associatively on the bismuth doped samples. The complex impedance behaviour of the electrode reaction can be interpreted in terms of R-C circuits in the PO₂ range of 10⁻²−1 atm.