A symmetrical electrochemical cell Bi3Ru3O11−35 wt % Bi2O3 porous electrode|Bi2O3−0.2 wt % B2O3 solid-molten electrolyte|Bi3Ru3O11−35 wt % Bi2O3 porous electrode is developed. The values of the cell ohmic and polarization resistances, Faraday efficiency, and oxygen permeation flux of the cell were measured using impedance spectroscopy and Coulomb volumetric technique at 740°C. These values are 0.046 and 0.077 Ω cm2, 97%, and 5×10–7 mol cm–2 s–1, respectively. The effect of wetting of the porous electrode surface on the polarization resistance was analyzed. The Bi3Ru3O11−35 wt % Bi2O3 and solid-molten Bi2O3−0.2 wt % B2O3 composites have a great potential to be used as the electrode and electrolyte materials in electrochemical oxygen generators.