The operating temperature of thermal energy storage medium is required to reach over 1 000 ℃ in supercritical carbon dioxide(S-CO_2) cycle for concentrated solar power. This can effectively improve the efficiency of solar thermal power generation and reduce the cost of solar thermal power generation. Solid particles can be used as working medium for heat collection and storage at high temperature

and investigations on their properties and selection are very important for the development of S-CO_2 solar thermal power generation technology. This paper summarizes the studies on various thermal energy storage particles and their properties applied in the field of solar thermal power generation in recent years

including optical properties

thermophysical properties

thermal stability and abrasion resistance. Furthermore

key issues on studies on solid particles in S-CO_2 solar thermal power generation system are discussed. It points out that

the future study should be strengthened in comprehensive analysis of the properties of solid particles

and the preparation of particles with high absorptance via surface modification or adding pigments becomes the new hot subject. Moreover

it is necessary to carry out further research on thermal cycling stability of specific heat capacity and thermal conductivity of the particles

as well as the cost taking into account the particles properties and the shortening of service life due to abrasion and invalidation.