Electrical conductivity, oxygen ion transference numbers and thermal e
xpansion of solid solutions Bi(Zr,Y)O-1.5 and Bi(Y,Pr)O-1.5 have been
investigated from the standpoint of their use for high temperature oxy
gen pumps. It has been found that use of solid electrolytes of ternary
system Bi2O3-ZrO2-Y2O3, having high ionic conductivity, offers reduct
ion in the polarization resistance of electrochemical cells with silve
r electrodes, as compared with electrolytes Bi(Y)O-1.5. Formation of c
ontinuous series of solid solutions with mixed ionic and electronic co
nductivity has been ascertained for the system (Bi(1-x)YxO(1.5))(1-y)(
PrO1.833)(y) at x=0.25-0.50 and y=0-0.15. Oxygen ion transference numb
ers for the ceramics containing praseodimia are 0.85+/-0.10. Cermet el
ectrodes containing silver and cobaltites Ln(Sr)CoO3-delta (Ln is a ra
re earth element) possess much higher electrochemical activity than el
ectrodes containing cobaltite only, and show better mechanical strengt
h in comparison with silver electrodes.