Thermochemical redox processes involving novel oxygen ion conducting materials with perovskites structure are studied to evaluate their application potential for solar energy storage in concentrated solar power plants. A series of Ba and Sr containing perovskites was synthesized via modified Pechini method and their crystal structure was characterized by XRD. The thermochemical reduction-oxidation steps of the redox cycle and oxygen exchange capacity of the perovskites were investigated by thermogravimetric (TG) analysis. The results revealed that Co-based perovskites are the most promising candidates for solar thermochemical energy storage application. The O-2 release/absorption of Co-based perovskites is completed in a reversible way when reaching a given temperature. BaCoO3 reduction occurs promptly when the temperature reaches 900 degrees C in Ar atmosphere (pO(2) = 10(-6) atm), and the oxidation proceeds completely as soon as the gas is switched from Ar to 20% O-2 at 600 degrees C. In these conditions, the amount of monatomic oxygen released captured reaches 0.47/0.49 mol per mol BaCoO3. Part substitution in A site improves the O-2 exchange capacity of Ba0.5Sr0.5FeO3-delta but not Ba0.5Sr0.5CoO3-delta, while part substitution in B-site improves the O-2 exchange capacity of SrCo0.8Fe0.2O3-delta and SrCo0.2Fe0.8O3-delta. Part substitution together in A-site and B-site of perovskites does not improve the O-2 exchange capacity of Ba0.5Sr0.5Co0.8Fe0.2O3-delta and Ba0.5Sr0.5Co0.2Fe0.8O3-delta. The Fe-based perovskites generally exhibit continuous non-stoichiometry changes according to the temperature change suggesting continuous topotactic evolution, while the non-stoichiometry of Mn-based systems is almost not changed at the considered temperatures. Ba containing systems (BaCoO3, BaFeO3 and Ba0.5Sr0.5CoO3) show the largest oxygen release ability under inert (pO(2) = 10(-6) atm) or oxidizing atmosphere (pO(2) = 0.2 atm) up to 1050 degrees C, while only BaCoO3 can be fully re-oxidized at 600 degrees C in a 20% O-2 atmosphere, with an energy storage capacity of 292 J/g. (C) 2016 Elsevier Ltd. All rights reserved.