As a new type of heat storage and heat transfer medium

molten salt has been widely used in concentrating solar power (CSP) system due to its wide working temperature range

relatively high specific and strong heat storage capacity. Increasing the specific heat capacity of the molten salt can significantly increase its heat storage density. Nanofluids were synthesized by dispersing 20 nm SiO2 and MgO particles to binary carbonate eutectic (Li2CO3 and K2CO3). The specific heat capacity effect of nanoparticles on molten salt was characterized by DSC measurement. Results show that mass fraction of 20 nm nanoparticles significantly enhanced the specific heat of binary carbonate eutectic. Compared with the base salt

the average specific heat improved with 20 nm MgO and SiO2 nanoparticles was found to be 27.5%-34.1%

11%-20.7%

respectively. The change rate of the specific heat values of the two nanofluids is lower than 4.31% after multiple solid-liquid cycles. The molten salt nanofluids showed good thermal stability. The microstructure of nanofluids was characterized by scanning electron microscopy (SEM). The images of nanofluids in solid state showed that special nanostructures were formed on the surface of molten salts.