Perovskite has been considered a promising thermochemical energy storage material. Such materials can perform redox reactions reversibly under the control of oxygen partial pressure over a wide range of temperatures. Layered perovskites have been poorly studied as energy storage material, although their oxygen species exhibit good oxidation activity. In this work, Ruddlesden-Popper-type quasi-2D perovskite Sr 3 Fe 2 O 7-δ and 3D perovskite SrFeO 3-δ were prepared for the testing of thermochemical energy storage properties. It was shown that the degree of reduction reaction for Sr 3 Fe 2 O 7-δ was much greater than that of SrFeO 3-δ , with change of non-stoichiometry up to 0.79. The combined effect of thermodynamic parameters for samples on heat storage behavior was studied by Van't Hoff method. The reduction entropy of Sr 3 Fe 2 O 7-δ is much higher than that of SrFeO 3-δ , which explains the large promotion in the reaction degree of SrFeO 3-δ . The total reduction enthalpy of Sr 3 Fe 2 O 7-δ is about 2.8 times that of SrFeO 3-δ , with both reduction enthalpy and reaction entropy affecting the heat storage capacity. Sr 3 Fe 2 O 7-δ also has an attractive spectral absorption of 96.92% in the range of 300-2500 nm, which makes it advantageous in volumetric solar collector. Overall, Sr 3 Fe 2 O 7-δ offers improved performance in terms of thermochemical energy storage compared to SrFeO 3-δ .