Thermochemical energy storage via isothermal carbonation-calcination cycles of MgO-stabilized SrO in the range of 1000–1100 °C

The reversible gas-solid thermochemical reaction between CO 2 and SrO to form SrCO 3 is considered for storing high-temperature heat delivered by concentrated solar energy systems. To maintain cycling stability, MgO-stabilized SrO-based materials were synthetized with various precursors and support contents by the co-precipitation, sol–gel, wet-mixing and dry-mixing production methods. Samples were analysed by thermogravimetry over multiple consecutive carbonation-calcination cycles in the range of 1000–1100 °C. The best performance was obtained by using the wet-mixing method with strontium acetate hemihydrate and porous magnesium oxide as precursors: the formulation with 40 wt% SrO featured stable chemical conversion over 100 consecutive carbonation-calcination cycles at 1000 °C and yielded gravimetric energy density of 0.81 MJ/kg.