Solar power (CSP) systems in the s-CO2 Brayton cycle use large mirror areas to concentrate solar radiation onto the receiver and provide this energy to a heat transfer medium for producing electricity in a conventional steam cycle. For the heat transfer media, solid particles offer a tremendous advantage over air because they can be directly used as thermal storage media. However, besides heat transfer properties, particles’ structural integrity at an elevated temperature is crucial because they must withstand extreme mechanical loads at a high temperature. Here, we propose the ICME approach to understand the microstructure-property relationships of the solid particles with the focus on the multiscale materials modeling to quantitatively describe how microstructural features of solid particles govern their mechanical properties at elevated temperatures and various strain rates. The knowledge gained can shorten the time required for designing the microstructure of solid particles with an improved lifetime.