Abstract: In order to increase the specific heat capacity of molten salt，a low-melting-point molten salt nanocomposite was obtained through ultrasonic dispersion and microwave method，by doping SiO2 nanoparticles with an average size of 20 nm into the independently developed quaternary mixed nitrates . The mass concentration of SiO2 was 1%. The specific heat capacity of molten salt nanocomposite was measured with a differential scanning calorimeter（DSC）. The experimental results showed that the specific heat capacity of nanocomposite could be enhanced by about 38.8%，which was much higher than that of nanocomposite prepared by traditional drying method which can be increased by only 19.4%. The microstructure characterization of the molten salt nanocomposite was analyzed by a scanning electron microscope（SEM）， which showed that the special nanostructure（resembling chain-like nanostructure）formed on the surface of the solid salt who was dried by microwave. The special nanostructure with large specific surface area and high surface energy can enhance the specific heat capacity. Furthermore，the microwave drying can improve the preparation efficiency of the molten salt nanocomposite.

Key words:  , heat storage material；molten salt；nanoparticles；microwave drying；nanostructure；specific heat capacity