Supercritical carbon dioxide(S-CO_2) cycle has attracted extensive attention due to its clean

high-efficiency and low-carbon characteristics. The working fluid used in semi-closed S-CO_2 cycle is CO_2 mixtures

so a deeper understanding and description of thermodynamic properties of the CO_2 mixutres is required during the research. Based on a critical review

the present knowledge gaps in the experimental data and calculation models of the mixtures containing CO_2 are identified. The analysis shows that

basic experimental data of single-phase density(i.e. PVTx property)

specific heat capacity and sound velocity of CO_2 mixure system are very scarce. The accuracy of the existing semi-theoretical equation of state needs further improvement. The multi-parameter equation of state needs to improve the effective application range. It is recommended to carry out well-targeted experimental and theoretical research to meet the requirements of the S-CO_2 cycle.