are highly desirable. [2] The intermittent nature of renewable electricity generated from wind and solar requires considerable compensation from other energy sources, limiting their shares in the power grid. [3][4][5][6] Therefore, energy storage systems, which reduce the temporal and spatial imbalances between electricity generation and consumption, will play a critical role in accelerating the renewable transition. [7] Various energy storage approaches have been proposed to store different forms of energy, such as pumped hydro, batteries, compressed air, flywheels, and thermal energy storage (TES). [8,9] Among these, TES is considered to be one of the most cost-effective approaches to overcoming the intermittency of concentrated solar power. [10,11] In addition, TES can directly utilize the widely available heat resources from industrial processes such as steel mills, glass furnaces, and thermal power plants. [12,13] By 2022, TES has the secondhighest installed capacity of 234 GWh and is expected to reach 800 GWh by 2030. [14] TES technology can be further categorized into three different types, i.e., sensible thermal energy storage (STES), latent thermal energy storage (LTES), and thermochemical energy storage (TCES). At present, the only commercially available TES technology is molten salt-based STES. [15] However, the solidification issue at low temperatures and the instability at high temperatures are the main barriers to the molten salt-based STES. [16] The operating temperature window for molten salt-based STES is typically limited to 200-600 °C, leading to a small energy density of 36-180 kJ kg −1 . [17][18][19] LTES technology relies on the heat uptake and release of phase change materials (PCMs), which can achieve a two to three times larger energy density within a narrower temperature window. [20] To date, medium (100-300 °C)/ high (>300 °C) temperature LTES has yet to be implemented due to various technical challenges such as the high-capital cost, poor thermal conductivity, and equipment corrosion by the liquid PCMs. [21][22][23] Over the past decade, TCES, which stores thermal heat via reversible chemical reactions, has become an important research direction owing to its promise in wide operating temperature ranges and high energy storage density. [24,25] Moreover, since the energy is stored in a chemical form, TCES is capable of long-term, long-distance, and even seasonal energyThe structural and compositional flexibility of perovskite oxides and their complex yet tunable redox properties offer unique optimization opportunities for thermochemical energy storage (TCES). To improve the relatively inefficient and empirical-based approaches, a high-throughput combinatorial approach for accelerated development and optimization of perovskite oxides for TCES is reported here. Specifically, thermodynamic-based screening criteria are applied to the high-throughput density functional theory (DFT) simulation results of over 2000 A/B-site doped SrFeO 3−δ . 61 promising TCES candidates are selected based on th...