Doped with tantalum cations a new prospective cathode material for solid oxide fuel cells of lanthanum strontium cobaltite was synthesized. High-temperature oxygen desorption was studied using the quasi-equilibrium oxygen release method, the ranges of oxygen nonstoichiometry were determined, and the values of thermodynamic functions of the system were obtained in the temperature ranges (600–850°C) and oxygen partial pressures (∼10−5– 0.2 atm).
